Abstract:
The invention relates to a sintered alloy. This sintered alloy includes 3-13.4 wt % of W, 0.4-5.6 wt % or 0.8-5.9 wt % of V, 0.2-5.6 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, 0.6-2.2 wt % of C, and a balance of Fe. The sintered alloy includes first and second phase which are distributed therein, in a form of spots, respectively. The second phase is in an amount of from 20 to 80 wt %, based on the total weight of the first and second phases. The first phase contains 3-7 wt % of W, 0.5-1.5 wt % of optional V, up to 1 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe. The second phase contains 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.1-0.6 wt % or 0.6-5.0 wt % of Si, 0.1-0.6 wt % or 0.2-1.0 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe. When the manganese contents of the first and second phases and the total of the sintered alloy are respectively in a range of from 0.2 to 1.0 wt %, sulfur is respectively contained therein in an amount of from 0.1 to 0.6 wt %. The sintered alloy has wear-resistant at high temperature and good compatibility without damaging mating part that is in contact with the sintered alloy.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates to an iron-based sintered alloy which is wear-resistant at high temperature. Such sintered alloy is preferably used as a material for mechanical parts (e.g., such as valve seat insert used in internal combustion engine) that require wear resistance at high temperature. 
     There are various conventional wear resistant materials. For example, Japanese Patent Examined Publication JP-B-5-55593 and Japanese Patent Unexamined Publication JP-A-7-233454 disclose high-temperature wear-resistant sintered alloys each being high in cobalt content. However, the production cost of these sintered alloys is high, due to the use of relatively large amounts of cobalt. 
     JP-A-5-9667 discloses an iron-based sintered alloy containing an iron-based matrix and an iron-based hard phase dispersed in the matrix. The hard phase contains C, Cr, Mo, W, V, Si, and Mn. JP-B-1-51539 discloses an iron-based sintered alloy containing an iron-based matrix and a dispersed phase containing Cr, C, Mo, Si, and at least one selected from Nb, Ta, Ti and V. According to these patent publications &#39;667 and &#39;539, however, it is difficult to prepare a sintered alloy that is superior in wear resistance and at the same time is weak in the property of damaging another member that is in contact with the sintered alloy. 
     SUMMARY OF THE INVENTION 
     It is therefore an object of the present invention to provide a sintered alloy that has wear-resistance at high temperature and good compatibility without damaging mating part that is in contact with the sintered alloy. 
     According to the following first to eighth aspects of the present invention, the sintered alloy has wear-resistance at high temperature and good compatibility without damaging mating part that is in contact with the sintered alloy. 
     According to the first aspect of the present invention, there is provided a high-temperature wear-resistant sintered alloy comprising, based on a total weight of said sintered alloy, 3-13.4 wt % of W, 0.4-5.6 wt % of V, 0.2-5.6 wt % of Cr, 0.1-0.6 wt % of Si, 0.1-0.6 wt % of Mn, 0.6-2.2 wt % of C, and a balance of Fe. This sintered alloy includes a first phase comprising, based on a total weight of said first phase, 3-7 wt % of W, up to 1 wt % of Cr, 0.1-0.6 wt % of Si, 0.1-0.6 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe; and a second phase comprising, based on a total weight of said second phase, 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.1-0.6 wt % of Si, 0.1-0.6 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe, said second phase being in an amount of from 20 to 80 wt %, based on a total weight of said first and second phases. 
     According to the second aspect of the present invention, there is provided a high-temperature wear-resistant sintered alloy comprising, based on a total weight of said sintered alloy, 3-13.4 wt % of W, 0.8-5.9 wt % of V, 0.2-5.6 wt % of Cr, 0.1-0.6 wt % of Si, 0.1-0.6 wt % of Mn, 0.6-2.2 wt % of C, and a balance of Fe. This sintered alloy includes a first phase comprising, based on a total weight of said first phase, 3-7 wt % of W, 0.5-1.5 wt % of V, up to 1 wt % of Cr, 0.1-0.6 wt % of Si, 0.1-0.6 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe; and a second phase comprising, based on a total weight of said second phase, 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.1-0.6 wt % of Si, 0.1-0.6 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe, said second phase being in an amount of from 20 to 80 wt %, based on a total weight of said first and second phases. 
     According to the third aspect of the present invention, there is provided a high-temperature wear-resistant sintered alloy comprising, based on a total weight of said sintered alloy, 3-13.4 wt % of W, 0.4-5.6 wt % of V, 0.2-5.6 wt % of Cr, 0.1-0.6 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, 0.6-2.2 wt % of C, and a balance of Fe. This sintered alloy includes a first phase comprising, based on a total weight of said first phase, 3-7 wt % of W, up to 1 wt % of Cr, 0.1-0.6 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, up to 2.2 wt % of C, and a balance of Fe; and a second phase comprising, based on a total weight of said second phase, 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.1-0.6 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, up to 2.2 wt % of C, and a balance of Fe, said second phase being in an amount of from 20 to 80 wt %, based on a total weight of said first and second phases. 
     According to the fourth aspect of the present invention, there is provided a high-temperature wear-resistant sintered alloy comprising, based on a total weight of said sintered alloy, 3-13.4 wt % of W, 0.8-5.9 wt % of V, 0.2-5.6 wt % of Cr, 0.1-0.6 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, 0.6-2.2 wt % of C, and a balance of Fe. This sintered alloy includes a first phase comprising, based on a total weight of said first phase, 3-7 wt % of W, 0.5-1.5 wt % of V, up to 1 wt % of Cr, 0.1-0.6 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, up to 2.2 wt % of C, and a balance of Fe; and a second phase comprising, based on a total weight of said second phase, 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.1-0.6 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, up to 2.2 wt % of C, and a balance of Fe, said second phase being in an amount of from 20 to 80 wt %, based on a total weight of said first and second phases. 
     According to the fifth aspect of the present invention, there is provided a high-temperature wear-resistant sintered alloy comprising, based on a total weight of said sintered alloy, 3-13.4 wt % of W, 0.4-5.6 wt % of V, 0.2-5.6 wt % of Cr, 0.6-5.0 wt % of Si, 0.1-0.6 wt % of Mn, 0.6-2.2 wt % of C, and a balance of Fe. This sintered alloy includes a first phase comprising, based on a total weight of said first phase, 3-7 wt % of W, up to 1 wt % of Cr, 0.6-5.0 wt % of Si, 0.1-0.6 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe; and a second phase comprising, based on a total weight of said second phase, 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.6-5.0 wt % of Si, 0.1-0.6 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe, said second phase being in an amount of from 20 to 80 wt %, based on a total weight of said first and second phases. 
     According to the sixth aspect of the present invention, there is provided a high-temperature wear-resistant sintered alloy comprising, based on a total weight of said sintered alloy, 3-13.4 wt % of W, 0.8-5.9 wt % of V, 0.2-5.6 wt % of Cr, 0.6-5.0 wt % of Si, 0.1-0.6 wt % of Mn, 0.6-2.2 wt % of C, and a balance of Fe. This sintered alloy includes a first phase comprising, based on a total weight of said first phase, 3-7 wt % of W, 0.5-1.5 wt % of V, up to 1 wt % of Cr, 0.6-5.0 wt % of Si, 0.1-0.6 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe; and a second phase comprising, based on a total weight of said second phase, 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.6-5.0 wt % of Si, 0.1-0.6 wt % of Mn, up to 2.2 wt % of C, and a balance of Fe, said second phase being in an amount of from 20 to 80 wt %, based on a total weight of said first and second phases. 
     According to the seventh aspect of the present invention, there is provided a high-temperature wear-resistant sintered alloy comprising, based on a total weight of said sintered alloy, 3-13.4 wt % of W, 0.4-5.6 wt % of V, 0.2-5.6 wt % of Cr, 0.6-5.0 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, 0.6-2.2 wt % of C, and a balance of Fe. This sintered alloy includes a first phase comprising, based on a total weight of said first phase, 3-7 wt % of W, up to 1 wt % of Cr, 0.6-5.0 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, up to 2.2 wt % of C, and a balance of Fe; and a second phase comprising, based on a total weight of said second phase, 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.6-5.0 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, up to 2.2 wt % of C, and a balance of Fe, said second phase being in an amount of from 20 to 80 wt %, based on a total weight of said first and second phases. 
     According to the eighth aspect of the present invention, there is provided a high-temperature wear-resistant sintered alloy comprising, based on a total weight of said sintered alloy, 3-13.4 wt % of W, 0.8-5.9 wt % of V, 0.2-5.6 wt % of Cr, 0.6-5.0 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, 0.6-2.2 wt % of C, and a balance of Fe. This sintered alloy includes a first phase comprising, based on a total weight of said first phase, 3-7 wt % of W, 0.5-1.5 wt % of V, up to 1 wt % of Cr, 0.6-5.0 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, up to 2.2 wt % of C, and a balance of Fe; and a second phase comprising, based on a total weight of said second phase, 3-15 wt % of W, 2-7 wt % of V, 1-7 wt % of Cr, 0.6-5.0 wt % of Si, 0.2-1.0 wt % of Mn, 0.1-0.6 wt % of S, up to 2.2 wt % of C, and a balance of Fe, said second phase being in an amount of from 20 to 80 wt %, based on a total weight of said first and second phases. 
     According to each of the first to eighth aspects of the present invention, the first and second phases of the sintered alloy are distributed therein, in the form of spots, respectively. 
     According to the ninth aspect of the present invention, the sintered alloy of the first, second, fifth or sixth aspect of the present invention may comprise 0.3-1.6 wt % of MnS that is distributed in a boundary between a first grain of the first phase and a second grain of the second phase and/or in a pore of the sintered alloy. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a graph showing the wears of valve seat insert, valve and their total, under the use of unleaded gasoline, versus the tungsten content of the first phase of each sintered alloy; 
     FIG. 2 is a graph similar to FIG. 1, but showing those versus that of the second phase thereof; 
     FIG. 3 is a graph similar to FIG. 1, but showing those versus the vanadium content of the second phase thereof; 
     FIG. 4 is a graph similar to FIG. 3, but showing those versus that of the first phase thereof; 
     FIG. 5 is a graph similar to FIG. 4, but showing the wears thereof under the use of leaded gasoline versus that of the first phase thereof; 
     FIG. 6 is a graph similar to FIG. 1, but showing those versus the chromium content of the second phase thereof; 
     FIG. 7 is a graph similar to FIG. 7, but showing those versus that of the first phase thereof; 
     FIG. 8 is a graph similar to FIG. 1, but showing those versus the weight percent of the second phase, based on the total weight of the first and second phases; 
     FIG. 9 is a graph similar to FIG. 1, but showing those under the use of leaded gasoline versus the silicon content of the first or second phase thereof; 
     FIG. 10 is a graph similar to FIG. 9, but showing the radial crushing strength of each sintered alloy versus that; 
     FIG. 11 is a graph similar to FIG. 10, but showing that versus the manganese content of the first or second phase thereof; 
     FIG. 12 is a graph similar to FIG. 10, but showing that versus the precipitated MnS content of the first or second phase thereof; 
     FIG. 13 is a graph similar to FIG. 12, but showing the density of the compact of each powder mixture versus that; 
     FIG. 14 is a graph similar to FIG. 12, but showing the maximum cutting force of each sintered alloy versus that; 
     FIG. 14a is a graph similar to FIG. 10, but showing that versus the added MnS content of the first or second phase thereof; 
     FIG. 14b is a graph similar to FIG. 14a, but showing the density of the compact of each powder mixture versus that; 
     FIG. 14c is a graph similar to FIG. 14a, but showing the maximum cutting force of each sintered alloy versus that; 
     FIG. 15 is a graph similar to FIG. 1, but showing those under the use of leaded gasoline versus that; 
     FIG. 16 is a graph similar to FIG. 15, but showing those versus the tungsten content of the second phase thereof; 
     FIG. 17 is a graph similar to FIG. 15, but showing those versus the vanadium content of the second phase thereof; 
     FIG. 18 is a graph similar to FIG. 15, but showing those versus the chromium content of the second phase thereof; 
     FIG. 19 is a graph similar to FIG. 15, but showing those versus the chromium content of the first phase thereof; 
     FIG. 20 is a graph similar to FIG. 15, but showing those versus the weight percent of the second phase, based on the total weight of the first and second phases; 
     FIG. 21 is a graph similar to FIG. 15, but showing those versus the silicon content of the first or second phase thereof; 
     FIGS. 22-26 are graphs respectively similar to FIGS. 10-14, but showing the data of other samples of the sintered alloys; and 
     FIGS. 26a-26c are graphs respectively similar to FIGS. 14a-14c, but showing the data of other samples of the sintered alloys. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     According to each of the above-mentioned first, second, fifth and sixth aspects of the present invention, the sintered alloy may contain 0.3-1.6 wt % of MnS that is distributed in a boundary between first grains of the first phase and second grains of the second phase and/or in pores of the sintered alloy. Due to the inclusion of this MnS, the sintered alloy can be substantially improved in machinability. 
     According to each of the above-mentioned first to ninth aspects of the present invention, the sintered alloy may contain a first metal that is one of metallic copper and a copper alloy. This first metal may be contained in the sintered alloy in a manner that the first metal is incorporated into the sintered alloy by infiltrating pores of the sintered alloy with a first melt of the first metal. Thus, according to the first, second, fifth and sixth aspects of the present invention, the sintered alloy may contain both of the first metal and 0.3-1.6 wt % of the MnS. According to each of the above-mentioned first to ninth aspects of the present invention, the sintered alloy may contain a second metal that is one of metallic lead and a lead alloy. The second metal may be contained in the sintered alloy in a manner to impregnate pores of the sintered alloy with the melted second metal. Thus, according to the first, second, fifth and sixth aspects of the present invention, the sintered alloy may contain both of the second metal and 0.3-1.6 wt % of the MnS. According to each of the above-mentioned first to ninth aspects of the present invention, the sintered alloy may contain an acrylic resin that is incorporated thereinto in a manner that is the same as that of the second metals. Thus, according to the first, second, fifth and sixth aspects of the present invention, the sintered alloy may contain both of the acrylic resin and 0.3-1.6 wt % of the MnS. Due to the inclusion of the first or second metal as above, the sintered alloy can be far superior in wear resistance. Due to the inclusion of the second metal or acrylic resin as above, the sintered alloy can be further improved in machinability. 
     According to each of the fifth to eighth aspects of the present invention, the silicon content of each of the total of the sintered alloy and its first and second phases is adjusted to a range of from 0.6 to 5.0 wt %. According to each of the second, fourth, sixth and eighth aspects of the present invention, the vanadium content of the first phase of the sintered alloy is adjusted to a range of from 0.5 to 1.5 wt %. With these adjustments, the sintered alloy of each of the second and the fourth to eighth aspects of the present invention can be further improved in wear resistance even under a condition that this sintered alloy is used, for example, as a valve seat insert of an internal combustion engine running with leaded gasoline. By the above adjustment of the silicon content, the sintered alloys according to the fifth and seventh aspects of the present invention are respectively more improved in corrosion resistance, as compared with the sintered alloy according to the first aspect of the present invention, although these sintered alloys and the powder mixtures for preparing the same respectively become lower, in hardness and compressibility, than the sintered alloy of the first aspect of the present invention and than the powder mixture for preparing the same. By the above adjustment of the silicon content, the sintered alloys according to the sixth and eighth aspects of the present invention are also respectively more improved in corrosion resistance, as compared with the sintered alloy according to the second aspect of the present invention, although these sintered alloys and the powder mixtures for preparing the same respectively become lower, in hardness and compressibility, than the sintered alloy of the second aspect of the present invention and than the powder mixture for preparing the same. Thus, as stated above, the sintered alloy according to each of the fifth to eighth aspects of the present invention becomes superior in wear resistance under the above condition in which leaded gasoline is used. According to each of the fifth to eighth aspects of the present invention, if the silicon content is greater than 5.0 wt %, the sintered alloy becomes low in hardness. Furthermore, the powder mixture for preparing sintered alloy becomes substantially low in compressibility. If the silicon content is lower than 0.6 wt %, the sintered alloy does not sufficiently improved in corrosion resistance. According to each of the second, fourth, sixth and eighth aspects of the present invention, if the vanadium content of the first phase is lower than 0.5 wt %, the sintered alloy becomes low in wear resistance, due to the insufficient corrosion resistance. If it is higher than 1.5 wt %, the sintered alloy used as the valve seat insert becomes strong in the property of damaging the valve. 
     According to the third, fourth, seventh and eighth aspects of the present invention, the manganese and sulfur contents of each of the total of the sintered alloy and its first and second phases are respectively adjusted to a range of from 0.2 to 1.0 wt % and a range of from 0.1 to 0.6 wt %. With these adjustments, MnS precipitates in the first and second phases of the corresponding sintered alloys. Therefore, the sintered alloy can be substantially improved in machinability. If the manganese and sulfur contents are respectively higher than 1.0 wt % and 0.6 wt %, the powder mixture for preparing the sintered alloy becomes low in compressibility. With this, the sintered alloy becomes low in hardness. If the manganese and sulfur contents are respectively lower than 0.2 wt % and 0.1 wt %, MnS does not precipitate in a sufficient amount. Therefore, the sintered alloy does not sufficiently improved in machinability. 
     As compared with conventional sintered alloys containing large amounts of cobalt, the sintered alloy according to the present invention can be much more economically produced and is substantially improved in wear resistance. 
     According to each of the first to eighth aspects of the present invention, the first and second phases of the sintered alloy may respectively have first and second grains each of which has an average particle diameter of from 20 to 150 μm. 
     According to the first aspect of the present invention, the sintered alloy may have a first phase that is M 6  C-type tungsten carbide dispersed in the sintered alloy, and a second phase which is from 20 to 150 μm in average particle diameter, is reinforced with chromium, and is made of M 6  C-type tungsten carbide and MC-type vanadium carbide that are uniformly dispersed therein. With these first and second phases, when the sintered alloy is used as a valve seat insert of an internal combustion engine, it can be sufficiently weak in the property of damaging the valve. 
     In the present invention, if the tungsten content of the first phase of the sintered alloy is greater than 7 wt %, the sintered alloy used as the valve seat insert becomes strong in the property of damaging the valve. If the tungsten content thereof is less than 3 wt %, the sintered alloy used as the valve seat insert becomes inferior in wear resistance. As the chromium content of the first phase of the sintered alloy increases, the sintered alloy used as the valve seat insert becomes stronger in the property of damaging the valve. Thus, chromium may be omitted in the first phase of the sintered alloy, but the first phase may contain up to 1 wt % of chromium generated by the diffusion from the second phase into the first phase, at the time of sintering. 
     In the present invention, if the tungsten and vanadium contents of the second phase of the sintered alloy are respectively greater than 15 wt % and 7 wt %, the sintered alloy used as the valve seat insert becomes strong in the property of damaging the valve. If they are respectively lower than 3 wt % and 2 wt %, it becomes inferior in wear resistance. Due to the inclusion of 1-7 wt % of chromium in the second phase of the sintered alloy, the sintered alloy becomes improved in harden ability. Furthermore, the MC-type vanadium carbide deposits in the second phase, and thus the second phase becomes harder than the first phase. Therefore, the sintered alloy becomes uneven in hardness and thus becomes superior in wear resistance. If the chromium content of the second phase is greater than 7 wt %, the sintered alloy used as the valve seat insert becomes strong in the property of damaging the valve. If it is lower than 1 wt %, it becomes inferior in wear resistance. 
     According to the first to fourth aspects of the present invention, the silicon content of each of the total of the sintered alloy and its first and second phases is adjusted to a range of from 0.1 to 0.6 wt %, as mentioned above. If it is greater than 0.6 wt %, the sintered alloy becomes low in hardness. If it is lower than 0.1 wt %, it becomes low in hardness, too, due to the inferior sinterability. 
     According to the first, second, fifth and sixth aspects of the present invention, the manganese content of each of the total of the sintered alloy and its first and second phases is adjusted to a range of from 0.1 to 0.6 wt %, as mentioned above. Due to this adjustment, the sintered alloy becomes high in hardness. If it is greater than 0.6 wt %, it becomes low in hardness, due to the inferior sinterability. 
     In the invention, the weight ratio of the second phase to the first phase in the sintered alloy is in a range of from 20:100 to 80:100. If it is lower than 20:100, the sintered alloy used as the valve seat insert becomes low in wear resistance. If it is greater than 80:100, it becomes strong in the property of damaging the valve. 
     According to the second aspect of the present invention, the vanadium content of the first phase of the sintered alloy is adjusted to a range of from 0.5 to 1.5 wt %. With this, the sintered alloy is further improved in corrosion resistance, and thus is superior in wear resistance under the use of leaded gasoline. If it is less than 0.5 wt %, the sintered alloy becomes low in wear resistance, due to insufficient corrosion resistance. If it is greater than 1.5 wt %, the sintered alloy used as the valve seat insert becomes strong in the property of damaging the valve. 
     As stated above, according to each of the fifth to eighth aspects of the present invention, the silicon content of each of the total of the sintered alloy and its first and second phases is adjusted to a range of from 0.6 to 5.0 wt %. 
     The following nonlimitative example is illustrative of the present invention. 
     EXAMPLE 
     At first, powders (G1-G113), each having an average particle diameter of from 20 to 150 μm and a chemical composition as shown in Table 1, were prepared. Then, as shown in Table 2, each powder mixture was prepared by blending a powder for preparing the first phase, another powder for preparing the second phase, a graphite powder, and zinc stearate used as a lubricant, for 30 min, using a mixer. Then, each powder mixture was subjected to a pressure of 6.5 ton f/cm 2 , thereby to prepare a powder compact having an inner diameter of 20 mm, an outer diameter of 40 mm, and a thickness of 10 mm. After that, the powder compacts were sintered in an atmosphere of a destructive ammonia gas at 1180° C. for 30 min, thereby to obtain sintered alloys having sample numbers of from 1 to 138 and chemical compositions as shown in Tables 3a-3m. 
     As shown in Table 6, each of the sintered alloys of sample nos. 4, 22, 58, 124, 46, 112, 63 and 129 was infiltrated with melted copper by putting a copper powder compact on each sintered alloy, then by keeping it in an atmosphere of a destructive ammonia gas at 1140° C. for 30 min. Furthermore, each of these sintered alloys was impregnated with lead by immersing in a vacuum each sintered alloy into a lead melt heated at 550° C., followed by a pressurization to 8 atmospheric pressure through an enclosure of nitrogen gas. Still furthermore, each of these sintered alloys was impregnated with an acrylic resin by a vacuum impregnation method, followed by curing in hot water heated at 100° C. In Table 6, for example, sample nos. of 4, 4-Cu, 4-Pb, and 4-Resin respectively represent a sintered alloy of No. 4 with no impregnation, a sintered alloy of No. 4 impregnated with copper, that impregnated with lead, and that impregnated with an acrylic resin. 
     EVALUATION TESTS 
     A wear resistance test on the sintered alloys was conducted, as follows, in order to evaluate wear resistance of each sintered alloy. At first, the sintered alloys were formed into a shape of a valve seat insert of an internal combustion engine. In this test, each valve seat insert was installed on an exhaust port side of an internal combustion engine having in-line four cylinders with 16 valves and a displacement of 1,600 cc. These valves were made of SUH-36, and their valve faces were coated with stellite #32. The wear resistance test was conducted by operating the engine for 300 hr, with an engine rotation speed of 6,000 rpm, using an unleaded regular gasoline or a leaded gasoline. After the test, there was measured wear of each valve seat insert of the invention and of the corresponding valve. 
     A machinability test on the sintered alloys was conducted, as follows. In this test, outer surfaces of 50 pieces of each sintered alloy having an outer diameter of 40 mm and a thickness of 10 mm were cut by an Ohkuma-type lathe, with a rotation speed of 525 rpm, a machining stock of 0.5 mm, a running speed of 0.1 mm per revolution, and a super hard chip, without using any cutting oil. In this test, the maximum cutting force of the lathe was recorded as the result. 
     Radial crushing strength of each sintered alloy having an outer diameter of 40 mm, an inner diameter of 20 mm, and a thickness of 10 mm was determined with an autograph under a condition of a cross head speed of 0.5 mm/min. 
     The evaluation of compressibility of each powder mixture was conducted as follows. At first, each powder mixture was compacted under a load of 6 ton f, with an Amsler type testing machine, using a mold having a diameter of 11.3 mm. Then, the density of the powder compact was determined. 
     In each of FIGS. 1-26c, the numerals added in the graph represent the sample numbers of the sintered alloys. 
     The results of the above tests were interpreted as follows. As shown in FIG. 1 and the corresponding upper half of Table 4a, it was interpreted that the wear under the use of unleaded gasoline becomes sufficiently low by adjusting the tungsten content of the first phase to a range of from 3 to 7 wt %. Furthermore, as shown in FIG. 15 and the corresponding upper half of Table 4e, it was also interpreted that the wear under the use of leaded gasoline becomes sufficiently low by adjusting the tungsten content of the first phase to a range of from 3 to 7 wt %. As shown in FIG. 2 and the corresponding lower half of Table 4a, it was interpreted that the wear under the use of unleaded gasoline becomes sufficiently low by adjusting the tungsten content of the second phase to a range of from 3 to 15 wt %. Furthermore, as shown in FIG. 16 and the corresponding lower half of Table 4e, it was also interpreted that the wear under the use of leaded gasoline becomes sufficiently low by adjusting the tungsten content of the second phase to a range of from 3 to 15 wt %. As shown in FIG. 3 and the corresponding upper half of Table 4b, it was interpreted that the wear under the use of unleaded gasoline becomes sufficiently low by adjusting the vanadium content of the second phase to a range of from 2 to 7 wt %. Furthermore, as shown in FIG. 17 and the corresponding upper half of Table 4f, it was interpreted that the wear under the use of leaded gasoline becomes sufficiently low by adjusting the vanadium content of the second phase to a range of from 2 to 7 wt %. As shown in FIGS. 4 and 5 and the corresponding lower half of Table 4b, it was interpreted that the wear under the uses of unleaded and leaded gasolines becomes sufficiently low by adjusting the vanadium content of the first phase to a range of up to 1.5 wt %. As shown in FIG. 6 and the corresponding upper half of Table 4c, it was interpreted that the wear under the use of unleaded gasoline becomes sufficiently low by adjusting the chromium content of the second phase to a range of from 1 to 7 wt %. Furthermore, as shown in FIG. 18 and the corresponding lower half of Table 4f, it was interpreted that the wear under the use of leaded gasoline becomes sufficiently low by adjusting the chromium content of the second phase to a range of from 1 to 7 wt %. As shown in FIG. 7 and the corresponding lower half of Table 4c, it was interpreted that the wear under the use of unleaded gasoline becomes sufficiently low by adjusting the chromium content of the first phase to a range of up to 1 wt %. Furthermore, as shown in FIG. 19 and the corresponding upper half of Table 4g, it was interpreted that the wear under the use of leaded gasoline becomes sufficiently low by adjusting the chromium content of the first phase to a range of up to 1 wt %. As shown in FIG. 8 and the corresponding upper half of Table 4d, it was interpreted that the wear under the use of unleaded gasoline becomes sufficiently low by adjusting the weight ratio of the first phase to the second phase to a range of from 20:80 to 80:20. Furthermore, as shown in FIG. 20 and the corresponding lower half of Table 4g, it was also interpreted that the wear under the use of leaded gasoline becomes sufficiently low by adjusting the weight ratio of the first phase to the second phase to a range of from 20:80 to 80:20. As shown in FIGS. 9-10 and the corresponding upper half of Table 5a and FIGS. 21-22 and the corresponding upper half of Table 5d, it was interpreted that the wear resistance under the use of leaded gasoline and the radial crushing strength become sufficiently high by adjusting the silicon content of the first or second phase to a range of from 0.1 to 5.0 wt %. As shown in FIG. 11 and the corresponding lower half of Table 5a and FIG. 23 and the corresponding lower half of Table 5d, it was interpreted that the radial crushing strength becomes sufficiently high by adjusting the manganese content of the first or second phase to a range of from 0.1 to 0.6 wt %. 
     
                       TABLE 1______________________________________Powder Powder Composition (wt %)No.   Fe      W      V   Cr   Si   Mn   S    C    O______________________________________G1    Balance 0      0   0    0.3  0.3  0    0.6  0.3G2    Balance 2      0   0    0.3  0.3  0    0.6  0.3G3    Balance 3      0   0    0.3  0.3  0    0.6  0.3G4    Balance 5      0   0    0.3  0.3  0    0.6  0.3G5    Balance 7      0   0    0.3  0.3  0    0.6  0.3G6    Balance 8      0   0    0.3  0.3  0    0.6  0.3G7    Balance 10     0   0    0.3  0.3  0    0.6  0.3G8    Balance 5      0.5 0    0.3  0.3  0    0.6  0.3G9    Balance 5      1   0    0.3  0.3  0    0.6  0.3G10   Balance 5      1.5 0    0.3  0.3  0    0.6  0.3G11   Balance 5      2   0    0.3  0.3  0    0.6  0.3G12   Balance 5      5   0    0.3  0.3  0    0.6  0.3G13   Balance 5      0   0.9  0.3  0.3  0    0.6  0.3G14   Balance 5      0   1.4  0.3  0.3  0    0.6  0.3G15   Balance 5      0   4    0.3  0.3  0    0.6  0.3G16   Balance 5      0   0    0.05 0.3  0    0.6  0.3G17   Balance 5      0   0    0.1  0.3  0    0.6  0.3G18   Balance 5      0   0    0.6  0.3  0    0.6  0.3G19   Balance 5      0   0    0.7  0.3  0    0.6  0.3G20   Balance 5      0   0    2    0.3  0    0.6  0.3G21   Balance 5      0   0    5    0.3  0    0.6  0.3G22   Balance 5      0   0    7    0.3  0    0.6  0.3G23   Balance 5      0   0    0.3  0.05 0    0.6  0.3G24   Balance 5      0   0    0.3  0.1  0    0.6  0.3G25   Balance 5      0   0    0.3  0.2  0    0.6  0.3G26   Balance 5      0   0    0.3  0.6  0    0.6  0.3G27   Balance 5      0   0    0.3  0.7  0    0.6  0.3G28   Balance 5      0   0    0.3  1    0    0.6  0.3G29   Balance 5      0   0    0.3  0.05 0.03 0.6  0.3G30   Balance 5      0   0    0.3  0.1  0.07 0.6  0.3G31   Balance 5      0   0    0.3  0.2  0.13 0.6  0.3G32   Balance 5      0   0    0.3  0.3  0.2  0.6  0.3G33   Balance 5      0   0    0.3  0.6  0.4  0.6  0.3G34   Balance 5      0   0    0.3  0.7  0.47 0.6  0.3G35   Balance 5      0   0    0.3  1    0.67 0.6  0.3G36   Balance 5      0   0    0.3  1.5  1    0.6  0.3G37   Balance 0      5   4    0.3  0.3  0    0.6  0.3G38   Balance 2      5   4    0.3  0.3  0    0.6  0.3G39   Balance 3      5   4    0.3  0.3  0    0.6  0.3G40   Balance 7      5   4    0.3  0.3  0    0.6  0.3G41   Balance 12     5   4    0.3  0.3  0    0.6  0.3G42   Balance 15     5   4    0.3  0.3  0    0.6  0.3G43   Balance 16     5   4    0.3  0.3  0    0.6  0.3G44   Balance 18     5   4    0.3  0.3  0    0.6  0.3G45   Balance 12     0   4    0.3  0.3  0    0.6  0.3G46   Balance 12     1   4    0.3  0.3  0    0.6  0.3G47   Balance 12     2   4    0.3  0.3  0    0.6  0.3G48   Balance 12     7   4    0.3  0.3  0    0.6  0.3G49   Balance 12     8   4    0.3  0.3  0    0.6  0.3G50   Balance 12     10  4    0.3  0.3  0    0.6  0.3G51   Balance 12     5   0    0.3  0.3  0    0.6  0.3G52   Balance 12     5   1    0.3  0.3  0    0.6  0.3G53   Balance 12     2   2    0.3  0.3  0    0.6  0.3G54   Balance 12     7   7    0.3  0.3  0    0.6  0.3G55   Balance 12     8   8    0.3  0.1  0    0.6  0.3G56   Balance 12     10  10   0.3  0.2  0    0.6  0.3G57   Balance 12     5   4    0.05 0.3  0    0.6  0.3G58   Balance 12     5   4    0.1  0.3  0    0.6  0.3G59   Balance 12     5   4    0.6  0.3  0    0.6  0.3G60   Balance 12     5   4    0.7  0.3  0    0.6  0.3G61   Balance 12     5   4    2    0.3  0    0.6  0.3G62   Balance 12     5   4    5    0.3  0    0.6  0.3G63   Balance 12     5   4    7    0.3  0    0.6  0.3G64   Balance 12     5   4    0.3  0.05 0    0.6  0.3G65   Balance 12     5   4    0.3  0.1  0    0.6  0.3G66   Balance 12     5   4    0.3  0.2  0    0.6  0.3G67   Balance 12     5   4    0.3  0.6  0    0.6  0.3G68   Balance 12     5   4    0.3  0.7  0    0.6  0.3G69   Balance 12     5   4    0.3  1    0    0.6  0.3G70   Balance 12     5   4    0.3  0.05 0.03 0.6  0.3G71   Balance 12     5   4    0.3  0.1  0.07 0.6  0.3G72   Balance 12     5   4    0.3  0.2  0.13 0.6  0.3G73   Balance 12     5   4    0.3  0.3  0.2  0.6  0.3G74   Balance 12     5   4    0.3  0.6  0.4  0.6  0.3G75   Balance 12     5   4    0.3  0.7  0.47 0.6  0.3G76   Balance 12     5   4    0.3  1    0.67 0.6  0.3G77   Balance 12     5   4    0.3  1.5  1    0.6  0.3G78   Balance 0      1   0    0.3  0.3  0    0.6  0.3G79   Balance 2      1   0    0.3  0.3  0    0.6  0.3G80   Balance 3      1   0    0.3  0.3  0    0.6  0.3G81   Balance 7      1   0    0.3  0.3  0    0.6  0.3G82   Balance 8      1   0    0.3  0.3  0    0.6  0.3G83   Balance 10     1   0    0.3  0.3  0    0.6  0.3G84   Balance 5      1   0.9  0.3  0.3  0    0.6  0.3G85   Balance 5      1   1.4  0.3  0.3  0    0.6  0.3G86   Balance 5      1   4    0.3  0.3  0    0.6  0.3G87   Balance 5      1   0    0.05 0.3  0    0.6  0.3G88   Balance 5      1   0    0.1  0.3  0    0.6  0.3G89   Balance 5      1   0    0.6  0.3  0    0.6  0.3G90   Balance 5      1   0    0.7  0.3  0    0.6  0.3G91   Balance 5      1   0    2    0.3  0    0.6  0.3G92   Balance 5      1   0    5    0.3  0    0.6  0.3G93   Balance 5      1   0    7    0.3  0    0.6  0.3G94   Balance 5      1   0    0.3  0.05 0    0.6  0.3G95   Balance 5      1   0    0.3  0.1  0    0.6  0.3G96   Balance 5      1   0    0.3  0.2  0    0.6  0.3G97   Balance 5      1   0    0.3  0.6  0    0.6  0.3G98   Balance 5      1   0    0.3  0.7  0    0.6  0.3G99   Balance 5      1   0    0.3  1    0    0.6  0.3G100  Balance 5      1   0    0.3  0.05 0.03 0.6  0.3G101  Balance 5      1   0    0.3  0.1  0.07 0.6  0.3G102  Balance 5      1   0    0.3  0.2  0.13 0.6  0.3G103  Balance 5      1   0    0.3  0.3  0.2  0.6  0.3G104  Balance 5      1   0    0.3  0.6  0.4  0.6  0.3G105  Balance 5      1   0    0.3  0.7  0.47 0.6  0.3G106  Balance 5      1   0    0.3  1    0.67 0.6  0.3G107  Balance 5      1   0    0.3  1.5  1    0.6  0.3G108  Balance 5      0   0    2    0.3  0.2  0.6  0.3G109  Balance 5      1   0    2    0.3  0.2  0.6  0.3G110  Balance 12     5   4    2    0.3  0.2  0.6  0.3G111  Balance of Fe, 6.5 wt % Co, 1.5 wt % Ni, and 1.5 wt % MoG112  Balance of Co, 28 wt % Mo, 8.5 wt % Cr, and 2.5 wt % SiG113  MnS Powder______________________________________ 
    
     
                       TABLE 2______________________________________     Powder Mixture Composition (parts by weight)                         Gra- Lubri-       Powder   Powder   phite                              cant   MnSSample      for 1st  for 2nd  Pow- (Zinc  Pow-No.         Phase    Phase    der  Stearate)                                     der______________________________________W cont.in 1stPhase(wt %)0       1       G1 (50)  G41 (50)                           0.85 0.5    --2       2       G2 (50)  G41 (50)                           0.86 0.5    --3       3       G3 (50)  G41 (50)                           0.87 0.5    --5       4       G4 (50)  G41 (50)                           0.88 0.5    --7       5       G5 (50)  G41 (50)                           0.89 0.5    --8       6       G6 (50)  G41 (50)                           0.89 0.5    --10      7       G7 (50)  G41 (50)                           0.90 0.5    --W cont. in2nd Phase(wt %)0       8       G4 (50)  G37 (50)                           0.82 0.5    --2       9       G4 (50)  G38 (50)                           0.83 0.5    --3       10      G4 (50)  G39 (50)                           0.83 0.5    --7       11      G4 (50)  G40 (50)                           0.85 0.5    --12      4       G4 (50)  G41 (50)                           0.88 0.5    --15      12      G4 (50)  G42 (50)                           0.89 0.5    --16      13      G4 (50)  G43 (50)                           0.90 0.5    --18      14      G4 (50)  G44 (50)                           0.91 0.5    --V cont. in2nd Phase(wt %)0       15      G4 (50)  G45 (50)                           0.59 0.5    --1       16      G4 (50)  G46 (50)                           0.64 0.5    --2       17      G4 (50)  G47 (50)                           0.70 0.5    --5       4       G4 (50)  G41 (50)                           0.88 0.5    --7       18      G4 (50)  G48 (50)                           0.99 0.5    --8       19      G4 (50)  G49 (50)                           1.05 0.5    --V cont. in.2nd Phase(wt %)10      20      G4 (50)  G50 (50)                           1.17 0.5    --V cont. in1st Phase(wt %)0       4       G4 (50)  G41 (50)                           0.88 0.5    --0.5     21      G8 (50)  G41 (50)                           0.90 0.5    --1       22      G9 (50)  G41 (50)                           0.93 0.5    --1.5     23      G10 (50) G41 (50)                           0.96 0.5    --2       24      G11 (50) G41 (50)                           0.99 0.5    --5       25      G12 (50) G41 (50)                           1.17 0.5    --Cr cont. in2nd Phase(wt %)0       26      G4 (50)  G51 (50)                           0.88 0.5    --1       27      G4 (50)  G52 (50)                           0.88 0.5    --2       28      G4 (50)  G53 (50)                           0.88 0.5    --4       4       G4 (50)  G41 (50)                           0.88 0.5    --7       29      G4 (50)  G54 (50)                           0.88 0.5    --8       30      G4 (50)  G55 (50)                           0.88 0.5    --10      31      G12 (50) G56 (50)                           0.88 0.5    --Cr cont.in 1stPhase(wt %)0       4       G4 (50)  G41 (50)                           0.88 0.5    --0.9     32      G13 (50) G41 (50)                           0.88 0.5    --1.4     33      G14 (50) G41 (50)                           0.88 0.5    --4       34      G1S (50) G41 (50)                           0.88 0.5    --4       35      G1S (50) G51 (50)                           0.88 0.5    --Ratio of 1stPhase to 2ndPhase by wt.100:0   36      G4       --     0.55 0.5    --90:10   37      G4       G41    0.62 0.5    --80:20   38      G4       G41    0.68 0.5    --50:50   4       G4       G41    0.88 0.5    --20:80   39      G4       G41    1.07 0.5    --10:90   40      G4       G41    1.14 0.5    --0:100   41      --       G41    1.20 0.5    --Com.        G111 (84.15), G112                     0.85   0.5    --Sam-        (15), and Stampedple A       Lead Powder (2)Si cont.in 1st or 2ndPhase (wt %)0.05    42      G16 (50) G57 (50)                           0.88 0.5    --0.1     43      G17 (50) G58 (50)                           0.88 0.5    --0.3     4       G4 (50)  G41 (50)                           0.88 0.5    --0.6     44      G18 (50) G59 (50)                           0.88 0.5    --0.7     45      G19 (50) G60 (50)                           0.88 0.5    --2       46      G20 (50) G61 (50)                           0.88 0.5    --5       47      G21 (50) G62 (50)                           0.88 0.5    --7       48      G22 (50) G63 (50)                           0.88 0.5    --Mn cont.in 1st or 2ndPhase (wt %)0.05    49      G23 (50) G64 (50)                           0.88 0.5    --0.1     50      G24 (50) G65 (50)                           0.88 0.5    --0.2     51      G25 (50) G66 (50)                           0.88 0.5    --0.3     4       G4 (50)  G41 (50)                           0.88 0.5    --0.6     52      G26 (50) G67 (50)                           0.88 0.5    --0.7     53      G27 (50) G68 (50)                           0.88 0.5    --1       54      G28 (50) G69 (50)                           0.88 0.5    --PrecipitatedMnS cont.in 1st or 2ndPhase (wt %)0.08    55      G29 (50) G70 (50)                           0.88 0.5    --0.17    56      G30 (50) G71 (50)                           0.88 0.5    --0.33    57      G31 (50) G72 (50)                           0.88 0.5    --0.5     58      G32 (50) G73 (50)                           0.88 0.5    --1       59      G33 (50) G74 (50)                           0.88 0.5    --1.17    60      G34 (50) G75 (50)                           0.88 0.5    --1.67    61      G35 (50) G76 (50)                           0.88 0.5    --2.5     62      G36 (50) G77 (50)                           0.88 0.5    --(MnS + Si)cont. in 1stor2nd Phase(wt %)0.3     4       G4 (50)  G41 (50)                           0.88 0.5    --2.5     63      G108 (50)                    G110 (50)                           0.88 0.5    --MnS Powder(parts byweight)0       4       G4 (50)  G41 (50)                           0.88 0.5    00.1     64                                  0.10.2     65                                  0.20.3     66                                  0.30.5     67                                  0.51.0     68                                  1.01.2     69                                  1.21.6     70                                  1.62.5     71                                  2.5MnSPowder &amp;Si in 1stand 2ndPhases(parts bywt.)0.3     4       G4 (50)  G41 (50)                           0.88 0.5    02.5     72      G20 (50) G61 (50)                           0.88 0.5    0.5W cont.in 1stPhase(wt %)0       73      G78 (50) G41 (50)                           0.91 0.5    --2       74      G79 (50) G41 (50)                           0.92 0.5    --3       75      G80 (50) G41 (50)                           0.92 0.5    --5       22      G9 (50)  G41 (50)                           0.93 0.5    --7       76      G81 (50) G44 (50)                           0.94 0.5    --8       77      G82 (50) G41 (50)                           0.95 0.5    --10      78      G83 (50) G41 (50)                           0.96 0.5    --W cont.in 2ndPhase(wt %)0       79      G9 (50)  G37 (50)                           0.87 0.5    --2       80      G9 (50)  G38 (50)                           0.88 0.5    --3       81      G9 (50)  G39 (50)                           0.89 0.5    --7       82      G9 (50)  G40 (50)                           0.91 0.5    --12      22      G9 (50)  G41 (50)                           0.93 0.5    --15      83      G9 (50)  G42 (50)                           0.95 0.5    --16      84      G9 (50)  G43 (50)                           0.95 0.5    --18      85      G9 (50)  G44 (50)                           0.96 0.5    --V cont.in 2ndPhase(wt %)0       86      G9 (50)  G45 (50)                           0.64 0.5    --1       87      G9 (50)  G46 (50)                           0.70 0.5    --2       88      G9 (50)  G47 (50)                           0.76 0.5    --5       22      G9 (50)  G41 (50)                           0.93 0.5    --7       89      G9 (50)  G48 (50)                           1.05 0.5    --8       90      G9 (50)  G49 (50)                           1.11 0.5    --10      91      G9 (50)  GSO (50)                           1.22 0.5    --Cr cont.in 2ndPhase(wt %)0       92      G9 (50)  G51 (50)                           0.93 0.5    --1       93      G9 (50)  G52 (50)                           0.93 0.5    --2       94      G9 (50)  G53 (50)                           0.93 0.5    --4       22      G9 (50)  G41 (50)                           0.93 0.5    --7       95      G9 (50)  G54 (50)                           0.93 0.5    --8       96      G9 (50)  G55 (50)                           0.93 0.5    --10      97      G9 (50)  G56 (50)                           0.93 0.5    --Cr cont.in 1stPhase(wt %)0.2     22      G9 (50)  G41 (50)                           0.93 0.5    --1       98      G84 (50) G41 (50)                           0.93 0.5    --1.5     99      G85 (50) G41 (50)                           0.93 0.5    --4       100     G86 (50) G41 (50)                           0.93 0.5    --4       101     G86 (50) G51 (50)                           0.93 0.5    --Ratio of 1stPhase to 2ndPhase by wt.100:0   102     G9       --     0.57 0.5    --90:10   103     G9       G41    0.72 0.5    --80:20   104     G9       G41    0.77 0.5    --50:50   22      G9       G41    0.93 0.5    --20:80   105     G9       G41    1.09 0.5    --10:90   106     G9       G41    1.15 0.5    --0:100   107     --       G41    1.20 0.5    --Si cont.in 1st or 2ndPhase (wt %)0.05    108     G87 (50) G57 (50)                           0.93 0.5    --0.1     109     G88 (50) G58 (50)                           0.93 0.5    --0.3     22      G9 (50)  G41 (50)                           0.93 0.5    --0.6     110     G89 (50) G59 (50)                           0.93 0.5    --0.7     111     G90 (50) G60 (50)                           0.93 0.5    --2       112     G91 (50) G61 (50)                           0.93 0.5    --5       113     G92 (50) G62 (50)                           0.93 0.5    --7       114     G93 (50) G63 (50)                           0.93 0.5    --Mn cont.in 1st or 2ndPhase (wt %)0.05    115     G94 (50) G64 (50)                           0.93 0.5    --0.1     116     G95 (50) G65 (50)                           0.93 0.5    --0.2     117     G96 (50) G66 (50)                           0.93 0.5    --0.3     22      G9 (50)  G41 (50)                           0.93 0.5    --0.6     118     G97 (50) G67 (50)                           0.93 0.5    --0.7     119     G98 (50) G68 (50)                           0.93 0.5    --1       120     G99 (50) G69 (50)                           0.93 0.5    --PrecipitatedMnS cont.in 1st or 2ndPhase (wt %)0.08    121     G100 (50)                    G70 (50)                           0.93 0.5    --0.17    122     G101 (50)                    G71 (50)                           0.93 0.5    --0.33    123     G102 (50)                    G72 (50)                           0.93 0.5    --0.5     124     G103 (50)                    G73 (50)                           0.93 0.5    --1       125     G104 (50)                    G74 (50)                           0.93 0.5    --1.17    126     G105 (50)                    G75 (50)                           0.93 0.5    --1.67    127     G106 (50)                    G76 (50)                           0.93 0.5    --2.5     128     G107 (50)                    G77 (50)                           0.93 0.5    --(MnS + Si)cont. in 1stor 2nd Phase(wt %)0.3     22      G9 (50)  G41 (50)                           0.93 0.5    --2.5     129     G109 (50)                    G110 (50)                           0.93 0.5    --MnS Powder(parts byweight)0       22      G9 (50)  G41 (50)                           0.93 0.5    00.1     130                                 0.10.2     131                                 0.20.3     132                                 0.30.5     133                                 0.51.0     134                                 1.01.2     135                                 1.21.6     136                                 1.62.5     137                                 2.5MnSPowder &amp;Si in 1stand 2ndPhases(parts bywt.)0.3     22      G9 (50)  G41 (50)                           0.93 0.5    02.5     138     G91 (50) G61 (50)                           0.93 0.5    0.5______________________________________ 
    
     
                                           TABLE 3a__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase      Total  No.     Fe W V Cr Si Mn S Fe W  V Cr                                 Si Mn S C__________________________________________________________________________W cont. in 1stPhase (wt %)0      1  Bal.        0 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.152      2  Bal.        2 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.163      3  Bal.        3 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.175      4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.187      5  Bal.        7 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.198      6  Bal.        8 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.1910     7  Bal.        10          0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.20W cont. in2nd Phase(wt %)0      8  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          0  5 4 0.3                                    0.3                                       0 1.122      9  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          2  5 4 0.3                                    0.3                                       0 1.133      10 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          3  5 4 0.3                                    0.3                                       0 1.137      11 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          7  5 4 0.3                                    0.3                                       0 1.1512     4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.1815     12 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          15 5 4 0.3                                    0.3                                       0 1.1916     13 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          16 5 4 0.3                                    0.3                                       0 1.2018     14 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          18 5 4 0.3                                    0.3                                       0 1.21__________________________________________________________________________ 
    
     
                                           TABLE 3b__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase      Total  No.     Fe W V Cr Si Mn S Fe W  V Cr                                 Si Mn S C__________________________________________________________________________V cont. in 2ndPhase (wt %)0      15 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 0 4 0.3                                    0.3                                       0 0.891      16 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 1 4 0.3                                    0.3                                       0 0.942      17 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 2 4 0.3                                    0.3                                       0 1.005      4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.187      18 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 7 4 0.3                                    0.3                                       0 1.298      19 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 8 4 0.3                                    0.3                                       0 1.3510     20 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 10                               4 0.3                                    0.3                                       0 1.47V cont. in 1stPhase (wt %)0      4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.8                                       0 1.180.5    21 Bal.        5 0.5            0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.201      22 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.231.5    23 Bal.        5 1.5            0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.262      24 Bal.        5 2 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.295      25 Bal.        5 5 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.47__________________________________________________________________________ 
    
     
                                           TABLE 3c__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase      Total  No.     Fe W V Cr Si Mn S Fe W  V Cr                                 Si Mn S C__________________________________________________________________________Cr cont. in2nd Phase(wt %)0      26 Bal.        5 0 0  0.3                  0.3                     0 Bal.                          12 5 0 0.3                                    0.3                                       0 1.181      27 Bal.        5 0 0.05               0.3                  0.3                     0 Bal.                          12 5 1 0.3                                    0.3                                       0 1.182      28 Bal.        5 0 0.1               0.3                  0.3                     0 Bal.                          12 5 2 0.3                                    0.3                                       0 1.184      4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.187      29 Bal.        5 0 0.35               0.3                  0.3                     0 Bal.                          12 5 7 0.3                                    0.3                                       0 1.188      30 Bal.        5 0 0.4               0.3                  0.3                     0 Bal.                          12 5 8 0.3                                    0.3                                       0 1.1810     31 Bal.        5 0 0.s               0.3                  0.3                     0 Bal.                          12 5 10                                 0.3                                    0.3                                       0 1.15Cr cont. in1st Phase(wt %)0      4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.180.9    32 Bal.        5 0 1  0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.181.4    33 Bal.        5 0 1.5               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.184      34 Bal.        5 0 4  0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.184      35 Bal.        5 0 4  0.3                  0.3                     0 Bal.                          12 5 0.2                                 0.3                                    0.3                                       0 1.18__________________________________________________________________________ 
    
     
                                           TABLE 3d__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase      Total  No.     Fe W V Cr Si Mn S Fe W  V Cr                                 Si Mn S C__________________________________________________________________________Ratio of 1stPhase to 2ndPhase by wt.100:0  36 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 0.8590:10  37 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 0.9280:20  38 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 0.9850:50  4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.1820:80  39 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.3710:90  40 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.440:100  41 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.50Comparative  Fe-6.5Co-1.5Ni-1.5Mo-0.6Pb + 15%Co-28Mo-8.5Cr-2.5Si, with Pb  impregnationSample A__________________________________________________________________________ 
    
     
                                           TABLE 3e__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase      Total  No.     Fe W V Cr Si Mn S Fe W  V Cr                                 Si Mn S C__________________________________________________________________________Si cont. in 1stor 2nd Phase(wt %)0.05   42 Bal.        5 0 0.2               0.05                  0.3                     0 Bal.                          12 5 4 0.05                                    0.3                                       0 1.180.1    43 Bal.        5 0 0.2               0.1                  0.3                     0 Bal.                          12 5 4 0.1                                    0.3                                       0 1.180.3    4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.180.6    44 Bal.        5 0 0.2               0.6                  0.3                     0 Bal.                          12 5 4 0.6                                    0.3                                       0 1.180.7    45 Bal.        5 0 0.2               0.7                  0.3                     0 Bal.                          12 5 4 0.7                                    0.3                                       0 1.182      46 Bal.        5 0 0.2               2  0.3                     0 Bal.                          12 5 4 2  0.3                                       0 1.185      47 Bal.        5 0 0.2               5  0.3                     0 Bal.                          12 5 4 5  0.3                                       0 1.187      48 Bal.        5 0 0.2               7  0.3                     0 Bal.                          12 5 4 7  0.3                                       0 1.18Mn cont. in1st or 2ndPhase (wt %)0.05   49 Bal.        5 0 0.2               0.3                  0.05                     0 Bal.                          12 5 4 0.3                                    0.05                                       0 1.180.1    50 Bal.        5 0 0.2               0.3                  0.1                     0 Bal.                          12 5 4 0.3                                    0.1                                       0 1.180.2    51 Bal.        5 0 0.2               0.3                  0.2                     0 Bal.                          12 5 4 0.3                                    0.2                                       0 1.180.3    4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.180.6    52 Bal.        5 0 0.2               0.3                  0.6                     0 Bal.                          12 5 4 0.3                                    0.6                                       0 1.180.7    53 Bal.        5 0 0.2               0.3                  0.7                     0 Bal.                          12 5 4 0.3                                    0.7                                       0 1.181      54 Bal.        5 0 0.2               0.3                  1  0 Bal.                          12 5 4 0.3                                    1  0 1.18__________________________________________________________________________ 
    
     
                                           TABLE 3f__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase        Second Phase     Total  No.     Fe W V Cr Si Mn S  Fe W V Cr                                 Si                                   Mn S  C__________________________________________________________________________PrecipitatedMnS cont.in 1st or 2ndPhase (wt %)0.08   55 Bal.        5 0 0.2               0.3                  0.05                     0.03                        Bal.                           12                             5 4 0.3                                   0.05                                      0.03                                         1.180.17   56 Bal.        5 0 0.2               0.3                  0.1                     0.07                        Bal.                           12                             5 4 0.3                                   0.1                                      0.07                                         1.180.33   57 Bal.        5 0 0.2               0.3                  0.2                     0.13                        Bal.                           12                             5 4 0.3                                   0.2                                      0.13                                         1.180.5    58 Bal.        5 0 0.2               0.3                  0.3                     0.2                        Bal.                           12                             5 4 0.3                                   0.3                                      0.2                                         1.181      59 Bal.        5 0 0.2               0.3                  0.6                     0.4                        Bal.                           12                             5 4 0.3                                   0.6                                      0.4                                         1.181.17   60 Bal.        5 0 0.2               0.3                  0.7                     0.47                        Bal.                           12                             5 4 0.3                                   0.7                                      0.47                                         1.181.67   61 Bal.        5 0 0.2               0.3                  1  0.67                        Bal.                           12                             5 4 0.3                                   1  0.67                                         1.182.5    62 Bal.        5 0 0.2               0.3                  1.5                     1  Bal.                           12                             5 4 0.3                                   1.5                                      1  1.18PrecipitatedMnS + Si)cont. in 1st or2nd Phase(wt %)0.3    4  Bal.        5 0 0.2               0.3                  0.05                     0  Bal.                           12                             5 4 0.3                                   0.05                                      0  1.182.5    63 Bal.        5 0 0.2               0.3                  0.1                     0  Bal.                           12                             5 4 0.3                                   0.1                                      0  1.18__________________________________________________________________________ 
    
     
                                           TABLE 3g__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase      Total  No.     Fe W V Cr Si Mn S Fe W  V Cr                                 Si Mn S C__________________________________________________________________________Added MnSPowder (partsby weight)0      4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.180.1    64 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.180.2    65 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.180.3    66 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.180.5    67 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.181.0    68 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.181.2    69 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.181.6    70 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.182.5    71 Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.18Added MnSPowder &amp; Si in1st and 2ndPhases(parts by wt.)0.3    4  Bal.        5 0 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.182.5    72 Bal.        5 0 0.2               2  0.3                     0 Bal.                          12 5 4 2  0.3                                       0 1.18__________________________________________________________________________ 
    
     
                                           TABLE 3h__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase      Total  No.     Fe W V Cr Si Mn S Fe W  V Cr                                 Si Mn S C__________________________________________________________________________W cont. in 1stPhase (wt %)0      73 Bal.        0 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.212      74 Bal.        2 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.223      75 Bal.        3 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.225      22 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.237      76 Bal.        7 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.248      77 Bal.        8 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.2510     78 Bal.        10          1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.26W cont. in 2ndPhase (wt %)0      79 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          0  5 4 0.3                                    0.3                                       0 1.172      80 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          2  5 4 0.3                                    0.3                                       0 1.183      81 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          3  5 4 0.3                                    0.3                                       0 1.197      82 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          7  5 4 0.3                                    0.3                                       0 1.2112     22 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.2315     83 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          15 5 4 0.3                                    0.3                                       0 1.2516     84 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          16 5 4 0.3                                    0.3                                       0 1.2518     85 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          18 5 4 0.3                                    0.3                                       0 1.26__________________________________________________________________________ 
    
     
                                           TABLE 3i__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase      Total  No.     Fe W V Cr Si Mn S Fe W  V Cr                                 Si Mn S C__________________________________________________________________________V cont. in 2ndPhase (wt %)0      86 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 0 4 0.3                                    0.3                                       0 0.941      87 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 1 4 0.3                                    0.3                                       0 1.002      88 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 2 4 0.3                                    0.3                                       0 1.065      22 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.237      89 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 7 4 0.3                                    0.3                                       0 1.358      90 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 8 4 0.3                                    0.3                                       0 1.4110     91 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 10                               4 0.3                                    0.3                                       0 1.52Cr cont. in 2ndPhase (wt %)0      92 Bal.        5 1 0  0.3                  0.3                     0 Bal.                          12 5 0 0.3                                    0.3                                       0 1.231      93 Bal.        5 1 0.05               0.3                  0.3                     0 Bal.                          12 5 1 0.3                                    0.3                                       0 1.232      94 Bal.        5 1 0.1               0.3                  0.3                     0 Bal.                          12 5 2 0.3                                    0.3                                       0 1.234      22 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.237      95 Bal.        5 1 0.35               0.3                  0.3                     0 Bal.                          12 5 7 0.3                                    0.3                                       0 1.238      96 Bal.        5 1 0.4               0.3                  0.3                     0 Bal.                          12 5 8 0.3                                    0.3                                       0 1.2310     97 Bal.        5 1 0.5               0.3                  0.3                     0 Bal.                          12 5 10                                 0.3                                    0.3                                       0 1.23__________________________________________________________________________ 
    
     
                                           TABLE 3j__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase      Total  No.     Fe W V Cr Si Mn S Fe W  V Cr                                 Si Mn S C__________________________________________________________________________Cr cont. in 1stPhase (wt %)0.2    22 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.231      98 Bal.        5 1 1  0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.231.5    99 Bal.        5 1 1.5               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.234      100     Bal.        5 1 4  0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.234      101     Bal.        5 1 4  0.3                  0.3                     0 Bal.                          12 5 0 0.3                                    0.3                                       0 1.23Ratio of 1stPhase to 2ndPhase by wt.100:0  102     Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 0.9790:10  103     Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.0280:20  104     Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.0750:50  22 Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.2320:80  105     Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.3910:90  106     Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.450:100  107     Bal.        5 1 0.2               0.3                  0.3                     0 Bal.                          12 5 4 0.3                                    0.3                                       0 1.50__________________________________________________________________________ 
    
     
                                           TABLE 3k__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase  No.     Fe W V  Cr               Si Mn S Fe W V  Cr                                 Si Mn S C__________________________________________________________________________Si cont. in 1stor 2nd Phase(wt %)0.05   108     Bal.        5 1  0.2               0.05                  0.3                     0 Bal.                          12                            5  4 0.05                                    0.3                                       0 1.230.1    109     Bal.        5 1  0.2               0.1                  0.3                     0 Bal.                          12                            5  4 0.1                                    0.3                                       0 1.230.3    22 Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.230.6    110     Bal.        5 1  0.2               0.6                  0.3                     0 Bal.                          12                            5  4 0.6                                    0.3                                       0 1.230.7    111     Bal.        5 1  0.2               0.7                  0.3                     0 Bal.                          12                            5  4 0.7                                    0.3                                       0 1.232      112     Bal.        5 1  0.2               2  0.3                     0 Bal.                          12                            5  4 2  0.3                                       0 1.235      113     Bal.        5 1  0.2               5  0.3                     0 Bal.                          12                            5  4 5  0.3                                       0 1.237      114     Bal.        5 1  0.2               7  0.3                     0 Bal.                          12                            5  4 7  0.3                                       0 1.23Mn cont. in 1stor 2nd Phase(wt %)0.05   115     Bal.        5 1  0.2               0.3                  0.05                     0 Bal.                          12                            5  4 0.3                                    0.05                                       0 1.230.1    116     Bal.        5 1  0.2               0.3                  0.1                     0 Bal.                          12                            5  4 0.3                                    0.1                                       0 1.230.2    117     Bal.        5 1  0.2               0.3                  0.2                     0 Bal.                          12                            5  4 0.3                                    0.2                                       0 1.230.3    22 Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.230.6    118     Bal.        5 1  0.2               0.3                  0.6                     0 Bal.                          12                            5  4 0.3                                    0.6                                       0 1.230.7    119     BaI.        5 1  0.2               0.3                  0.7                     0 Bal.                          12                            5  4 0.3                                    0.7                                       0 1.231      120     Bal.        5 1  0.2               0.3                  1  0 Bal.                          12                            5  4 0.3                                    1  0 1.23__________________________________________________________________________ 
    
     
                                           TABLE 3l__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase         Second Phase  No.     Fe W V  Cr Si Mn S  Fe W V  Cr                                   Si                                     Mn S  C__________________________________________________________________________PrecipitatedMnS cont. in1st or 2ndPhase (wt %)0.08   121     Bal.        5 1  0.2                0.3                   0.05                      0.03                         Bal.                            12                              5  4 0.3                                     0.05                                        0.03                                           1.230.17   122     Bal.        5 1  0.2                0.3                   0.1                      0.07                         Bal.                            12                              5  4 0.3                                     0.1                                        0.07                                           1.230.33   123     Bal.        5 1  0.2                0.3                   0.2                      0.13                         Bal.                            12                              5  4 0.3                                     0.2                                        0.13                                           1.230.5    124     Bal.        5 1  0.2                0.3                   0.3                      0.2                         Bal.                            12                              5  4 0.3                                     0.3                                        0.2                                           1.231      125     Bal.        5 1  0.2                0.3                   0.6                      0.4                         Bal.                            12                              5  4 0.3                                     0.6                                        0.4                                           1.231.17   126     Bal.        5 1  0.2                0.3                   0.7                      0.47                         Bal.                            12                              5  4 0.3                                     0.7                                        0.47                                           1.231.67   127     Bal.        5 1  0.2                0.3                   1  0.67                         Bal.                            12                              5  4 0.3                                     1  0.67                                           1.232.5    128     Bal.        5 1  0.2                0.3                   1.5                      1  Bal.                            12                              5  4 0.3                                     1.5                                        1  1.23(PrecipitatedMnS + Si)cont.in 1st or 2ndPhase (wt %)0.3    22 Bal.        5 1  0.2                0.3                   0.3                      0  Bal.                            12                              5  4 0.3                                     0.3                                        0  1.232.5    129     Bal.        5 1  0.2                2  0.3                      0.2                         Bal.                            12                              5  4 2 0.3                                        0.2                                           1.23__________________________________________________________________________ 
    
     
                                           TABLE 3m__________________________________________________________________________  Sam-     Sintered Alloy Composition (wt %)  ple     First Phase       Second Phase  No.     Fe W V  Cr               Si Mn S Fe W V  Cr                                 Si Mn S C__________________________________________________________________________Added MnSPowder (partsby weight)0      22 Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.230.1    130     Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.230.2    131     Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.230.3    132     Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.230.5    133     Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.231.0    134     Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.231.2    135     Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.231.6    136     Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.232.5    137     Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.23Added MnSPowder &amp; Si in1st and 2ndPhases(parts by wt.)0.3    22 Bal.        5 1  0.2               0.3                  0.3                     0 Bal.                          12                            5  4 0.3                                    0.3                                       0 1.232.5    138     Bal.        5 1  0.2               2  0.3                     0 Bal.                          12                            5  4 2  0.3                                       0 1.23__________________________________________________________________________ 
    
     
                                           TABLE 4a__________________________________________________________________________                Wear in Unleaded Gasoline Test (μm)  Sam-      1st Phase           2nd Phase                Valve Seat  ple No.      (wt %)           (wt %)                Insert                     Valve Total__________________________________________________________________________W cont. in 1stPhase (wt %)0      1   50   50   130  5     1352      2   50   50   80   25    1053      3   50   50   60   20    805      4   50   50   40   24    647      5   50   50   70   28    988      6   50   50   78   36    11410     7   50   50   95   55    150W cont. in 2ndPhase (wt %)0      8   50   50   120  5     1252      9   50   50   96   29    1253      10  50   50   82   11    937      11  50   50   45   18    6312     4   50   50   40   24    6415     12  50   50   67   28    9516     13  50   50   79   44    12318     14  50   50   88   76    164__________________________________________________________________________ 
    
     
                                           TABLE 4b__________________________________________________________________________                Wear in Unleaded Gasoline Test (μm)                                Wear in Leaded Gasoline Test                                (μm)  Sam-      1st Phase           2nd Phase                Valve Seat      Valve Seat  ple No.      (wt %)           (wt %)                Insert                     Valve Total                                Insert                                     Valve Total__________________________________________________________________________V cont. in 2ndPhase (wt %)0      15  50   50   244  2     246  --   --    --1      16  50   50   125  5     130  --   --    --2      17  50   50   67   11    78   --   --    --5      4   50   50   40   24    64   --   --    --7      18  50   50   33   56    89   --   --    --8      19  50   50   58   89    147  --   --    --10     20  50   50   98   148   246  --   --    --V cont. in 1stPhase (wt %)0      4   50   50   40   24    64   58   38    960.5    21  50   50   45   28    73   38   25    631      22  50   50   55   31    86   14   28    421.5    23  50   50   59   35    94   28   35    632      24  50   50   68   58    126  55   48    1035      25  50   50   210  268   478  87   102   189__________________________________________________________________________ 
    
     
                                           TABLE 4c__________________________________________________________________________                Wear in Unleaded Gasoline Test (μm)  Sam-      1st Phase           2nd Phase                Valve Seat  ple No.      (wt %)           (wt %)                Insert                     Valve Total__________________________________________________________________________Cr cont. in 2ndPhase (wt %)0      26  50   50   140  32    1721      27  50   50   97   28    1252      28  50   50   58   18    764      4   50   50   40   24    647      29  50   50   35   38    738      30  50   50   55   59    11410     31  50   50   89   78    167Cr cont. in 1stPhase (wt %)0      4   50   50   40   24    640.9    32  50   50   55   35    901.4    33  50   50   88   33    1214      34  50   50   245  167   4124      35  50   50   125  43    168__________________________________________________________________________ 
    
     
                                           TABLE 4d__________________________________________________________________________        Wear in Unleaded Gasoline Test (μm)                        Wear in Leaded Gasoline Test (μm)    Sam-        Valve Seat      Valve Seat    ple No.        Insert             Valve Total                        Insert                             Valve Total__________________________________________________________________________Ratio of 1st Phaseto 2nd Phase by wt.100:0    36  342  4     346  --   --    --90:10    37  266  4     270  --   --    --80:20    38  89   8     97   --   --    --50:50    4   40   24    64   --   --    --20:80    39  25   37    62   --   --    --10:90    40  58   89    147  --   --    --0:100    41  89   177   266  --   --    --    Com.        102  5     107  88   12    100    Sample    A__________________________________________________________________________ 
    
     
                                           TABLE 4e__________________________________________________________________________                Wear in Leaded Gasoline Test (μm)  Sam-      1st Phase           2nd Phase                Valve Seat  ple No.      (wt %)           (wt %)                Insert                     Valve Total__________________________________________________________________________W cont. in 1stPhase (wt %)0      73  50   50   120  10    1302      74  50   50   93   18    1113      75  50   50   28   25    535      22  50   50   14   28    427      76  50   50   33   46    798      77  50   50   58   78    13610     78  50   50   68   98    166W cont. in 2ndPhase (wt %)0      79  50   50   119  12    1312      80  50   50   98   13    1113      81  50   50   59   11    707      82  50   50   36   12    4812     22  50   50   14   28    4215     83  50   50   56   33    8916     84  50   50   89   56    14518     85  50   50   98   60    158__________________________________________________________________________ 
    
     
                                           TABLE 4f__________________________________________________________________________                Wear in Leaded Gasoline Test (μm)  Sam-      1st Phase           2nd Phase                Valve Seat  ple No.      (wt %)           (wt %)                Insert                     Valve Total__________________________________________________________________________V cont. in 2ndPhase (wt %)0      86  50   50   380  5     3851      87  50   50   245  7     2522      88  50   50   68   10    785      22  50   50   14   28    427      89  50   50   23   48    718      90  50   50   54   76    13010     91  50   50   89   98    187Cr cont. in 2ndPhase (wt %)0      92  50   50   130  45    1751      93  50   50   88   44    1322      94  50   50   60   39    994      22  50   50   14   28    427      95  50   50   15   25    408      96  50   50   78   40    11810     97  50   50   98   65    163__________________________________________________________________________ 
    
     
                                           TABLE 4g__________________________________________________________________________                Wear in Leaded Gasoline Test (μm)  Sam-      1st Phase           2nd Phase                Valve Seat  ple No.      (wt %)           (wt %)                Insert                     Valve Total__________________________________________________________________________Cr cont. in 1stPhase (wt %)0.2    22  50   50   14   28    421      98  50   50   38   36    741.5    99  50   50   67   30    974      100 50   50   230  145   3754      101 50   50   276  89    365Ratio of1st Phaseto 2ndPhase by wt.100:0  102 100  0    246  1     24790:10  103 90   10   233  2     23580:20  104 80   20   78   5     8350:50  22  50   50   14   28    4220:80  105 20   80   26   40    6610:90  106 10   90   68   76    1440:100  107 0    100  78   167   245__________________________________________________________________________ 
    
     
                                           TABLE 5a__________________________________________________________________________                                 Radial                 Wear in Leaded Gasoline Test (μm)                                 Crushing   Sam-       1st Phase            2nd Phase                 Valve Seat      Strength   ple No.       (wt %)            (wt %)                 Insert                      Valve Total                                 (MPa)__________________________________________________________________________Si cont. in 1st or2nd Phase (wt %)0.05    42  50   50   450  50    500  2890.1     43  50   50   59   40    99   8320.3     4   50   50   58   38    96   9350.6     44  50   50   48   36    84   8370.7     45  50   50   29   20    49   7252       46  50   50   35   18    53   6105       47  50   50   37   15    52   5887       48  50   50   268  58    326  345Mn cont. in 1st or2nd Phase (wt %)0.05    49  50   50                   6000.1     50  50   50                   7880.2     51  50   50                   8960.3     4   50   50                   9350.6     52  50   50                   7990.7     53  50   50                   4881       54  50   50                   321__________________________________________________________________________ 
    
     
                                           TABLE 5b__________________________________________________________________________                                  Radial    Max.    Sam-          Wear in Leaded Gasoline Test (μm)                                  Crushing                                       Compact                                            Cutting    ple 1st Phase             2nd Phase                  Valve Seat      Strength                                       Density                                            Force    No. (wt %)             (wt %)                  Insert                       Valve Total                                  (MPa)                                       (g/cm.sup.3)                                            (kgf)__________________________________________________________________________Precipitated MnScont. in 1st or 2ndPhase (wt %)0.08     55  50   50                   911  6.88 780.17     56  50   50                   898  6.87 680.33     57  50   50                   862  6.85 540.5      58  50   50                   832  6.84 511        59  50   50                   788  6.8  481.17     60  50   50                   725  6.78 441.67     61  50   50                   675  6.76 412.5      62  50   50                   331  6.51 38(Precipitated MnS +Si) cont. in 1st or2nd Phase (wt %)0.3      4   50   50   58   38    96             812.5      63  50   50   35   18    53             53__________________________________________________________________________ 
    
     
                                           TABLE 5c__________________________________________________________________________                                 Radial                 Wear in Leaded Gasoline Test (μm)                                 Crushing                                      Compact                                           Max.   Sam-       1st Phase            2nd Phase                 Valve Seat      Strength                                      Density                                           Cutting   ple No.       (wt %)            (wt %)                 Insert                      Valve Total                                 (MPa)                                      (g/cm.sup.3)                                           Force (kgf)__________________________________________________________________________Added MnSPowder (parts byweight)0       4   50   50                   935  6.90 810.1     64  50   50                   920  6.87 800.2     65  50   50                   901  6.87 720.3     66  50   50                   868  6.86 570.5     67  50   50                   833  6.84 541.0     68  50   50                   790  6.81 531.2     69  50   50                   720  6.79 491.6     70  50   50                   671  6.75 432.5     71  50   50                   350  6.52 40Added MnSPowder &amp; Siin 1st and 2ndPhases (parts bywt.)0.3     4   50   50   58   38    96             812.5     72  50   50   38   15    53             55__________________________________________________________________________ 
    
     
                                           TABLE 5d__________________________________________________________________________                                 Radial                 Wear in Leaded Gasoline Test (μm)                                 Crushing   Sam-       1st Phase            2nd Phase                 Valve Seat      Strength   ple No.       (wt %)            (wt %)                 Insert                      Valve Total                                 (MPa)__________________________________________________________________________Si cont. in 1st or2nd Phase (wt %)0.05    108 50   50   450  50    500  2790.1     109 50   50   59   31    90   8210.3     22  50   50   19   28    47   9040.6     110 50   50   18   20    38   8170.7     111 50   50   15   20    35   7202       112 50   50   10   16    26   6055       113 50   50   37   15    52   5707       114 50   50   268  58    326  330Mn cont. in 1st or2nd Phase (wt %)0.05    115 50   50                   4040.1     116 50   50                   7780.2     117 50   50                   8780.3     22  50   50                   9040.6     118 50   50                   7120.7     119 50   50                   4681       120 50   50                   302__________________________________________________________________________ 
    
     
                                           TABLE 5e__________________________________________________________________________                                  Radial                  Wear in Leaded Gasoline Test (μm)                                  Crushing                                       Compact                                            Max.    Sam-        1st Phase             2nd Phase                  Valve Seat      Strength                                       Density                                            Cutting    ple No.        (wt %)             (wt %)                  Insert                       Valve Total                                  (MPa)                                       (g/cm.sup.3)                                            Force (kgf)__________________________________________________________________________Precipitated MnScont. in 1st or 2ndPhase (wt %)0.08     121 50   50                   902  6.77 850.17     122 50   50                   882  6.75 720.33     123 50   50                   850  6.74 600.5      124 50   50                   802  6.73 581        125 50   50                   761  6.69 571.17     126 50   50                   708  6.66 561.67     127 50   50                   666  6.64 512.5      128 50   50                   311  6.42 48(Precipitated MnS +Si) cont. in 1st or2nd Phase (wt %)0.3      22  50   50   14   28    42             872.5      129 50   50   8    18    26             60__________________________________________________________________________ 
    
     
                                           TABLE 5f__________________________________________________________________________                                 Radial                 Wear in Leaded Gasoline Test (μm)                                 Crushing                                      Compact                                           Max.   Sam-       1st Phase            2nd Phase                 Valve Seat      Strength                                      Density                                           Cutting   ple No.       (wt %)            (wt %)                 Insert                      Valve Total                                 (MPa)                                      (g/cm.sup.3)                                           Force (kgf)__________________________________________________________________________Added MnSPowder (parts byweight)0       22  50   50                   904  6.80 870.1     130 50   50                   903  6.78 860.2     131 50   50                   880  6.76 730.3     132 50   50                   852  6.75 580.5     133 50   50                   799  6.73 571.0     134 50   50                   759  6.70 571.2     135 50   50                   712  6.65 551.6     136 50   50                   660  6.63 522.5     137 50   50                   315  6.41 50Added MnSPowder &amp; Siin 1st and 2ndPhases (parts bywt.)0.3     22  50   50   14   28    42             872.5     138 50   50   7    13    20             62__________________________________________________________________________ 
    
     
                                           TABLE 6__________________________________________________________________________Wear in Unleaded Gasoline Test (μm)                Wear in Leaded Gasoline Test (μm)SampleValve Seat      Valve Seat      Max. CuttingNo.  Insert     Valve Total                Insert                     Valve Total                                Force (kgf)__________________________________________________________________________4    40   24    64   58   38    96   814-Cu 30   20    50   28   17    45   --4-Pb 25   10    35   60   10    70   384-Resin--   --    --   --   --    --   3222   55   31    86   14   28    42   8322-Cu35   28    63   8    16    24   --22-Pb28   11    39   14   5     19   4122-Resin--   --    --   --   --    --   3858   38   21    59   56   33    89   5158-Cu31   19    50   27   17    44   --58-Pb27   8     35   70   11    81   2558-Resin--   --    --   --   --    --   22124  52   28    80   16   21    37   58124-Cu34   21    55   10   13    23   --124-Pb30   17    47   16   7     23   26124-Resin--   --    --   --   --    --   2346                   35   18    53   8246-Cu                25   14    39   --46-Pb                37   10    47   3846-Resin             --   --    --   33112                  10   16    26   85112-Cu               5    4     9    --112-Pb               11   2     13   40112-Resin            --   --    --   3763                   35   18    53   5363-Cu                24   14    38   --63-Pb                36   8     44   2763-Resin             --   --    --   24129                  8    18    26   60129-Cu               4    5     9    --129-Pb               10   2     12   28129-Resin            --   --    --   25__________________________________________________________________________ 
    
     The entire disclosure of each of Japanese Patent Application No. 8-92752 filed on Apr. 15, 1996 and Japanese Patent Application No. 9-57943 filed on Mar. 12, 1997, including specification, claims, drawings and summary, is incorporated herein by reference in its entirety.