A tough, wear resistant body is provided. The body includes hard carbide particles embedded in and bonded with a first casted ferrous matrix material such as steel or cast iron. The body may be embedded in and bonded with a second steel matrix to form a wear resistant composite. The second steel matrix has a melting point at least 200 degrees F. greater than the melting point of the first ferrous matrix, thereby facilitating a metallurgical bond between the surface of the wear resistant body and the second steel matrix. The composite structure is particularly suitable for earthmoving and other severe mechanical applications.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
The present invention generally relates to wear-resistant castings and 
their manufacture and, more particularly, to articles having particles of 
sintered or cast hard carbides disposed in a casted steel alloy matrix, 
and to composite structures formed therefrom. 
2. Description of the Prior Art 
Parts for use in severe environments must combine wear resistance with 
toughness. Applications for such parts include earth or road engaging wear 
shoes, excavator teeth, and crusher teeth. 
Suitable wear-resistant materials have been made of cemented carbide alloys 
consisting of a finely dispersed hard carbide phase cemented together by 
cobalt or nickel or both. The materials are produced by compacting finely 
milled powders together followed by liquid phase sintering to achieve 
consolidation. Typically the cemented carbide alloys possess 
microstructures characterized by hard carbide grains generally in the 
range of 1-15 microns. However, such materials may be subject to chipping 
or cracking when utilized by themselves. For those applications, it is 
desirable to have the wear properties of carbide combined with the 
toughness of steel. 
The use of a cast iron or steel matrix as a binding material has proven 
difficult because the finely divided state and high specific surface of 
the dispersed hard carbide phases and the formation of comparatively 
brittle binder alloys of tungsten and iron with carbon. This reduces the 
free binder volume fraction of the body, thereby embrittling the sintered 
body. Unlike cobalt and nickel, the iron component of cast iron or steel 
will form a stable carbide (Fe3C) and has a greater tendency to form 
brittle binary carbides than either the cobalt or nickel binder materials. 
In addition, carbon transfer from the hard carbide phase or phases to the 
iron component is promoted by the presence of the liquid or plastic state 
of the iron or steel binder during liquid phase sintering when carried out 
at temperatures near to or above the melting point of the binder. However, 
useful wear resistant bodies have been made by casting a steel or cast 
iron melt into a bed of comparatively coarse hard carbide particulate. 
One such technique is set forth by the molten steel casting method of 
Charles S. Baum (U.S. Pat. Nos. 4,024,902 and 4,146,080). Unlike the prior 
art methods which had attempted to avoid the dissolution of the metallic 
carbide components into the matrixing alloy, Baum taught the placement of 
tungsten carbide particles of substantially larger size than those desired 
in the finished article in a mold in which the wear resistant body is to 
be formed. 
According to Baum, a steel alloy is separately heated and casted into the 
mold which is at a temperature below the temperature at which the metallic 
carbide dissolves. The size and placement o the particles are balanced 
with the temperature of the molten steel, the initial temperature of the 
mold, and the volume and surface area of the mold to insure that the heat 
of the molten steel causes a dissolving action at the surface of the 
particles and at least some of the particles still exist in reduced size 
when the molten steel freezes. The fusion of the carbon, tungsten and 
cobalt through the alloy also produces an alloy having superior strength, 
including greater strength than the original casted alloy. In addition, 
the degree of solubility may be controlled by the inclusion of some 
smaller sintered particles that totally dissolve as the molten metal 
solidifies. 
Another such wear resistant body is disclosed in U.S. Pat. No. 4,119,459 
issued to Ekemar. Ekemar found that cemented carbide could be bonded in a 
matrix of graphitic cast iron having a carbon equivalent in the range of 
from 2.5 to 6.0 weight percent (wt. %). Ekemar also found that a suitable 
adjustment of the particle size of the hard carbide gave the possibility 
to reach the desired relationship between completely transforming or 
partially transforming the hard carbide particles. 
It would be expected that the wear resistant bodies formed by the molten 
steel casting method may have superior physical properties over similar 
molten-cast iron bodies. For example, martensitic ductile cast iron can 
result in tensile strengths of up to 120 ksi, which is considered high for 
ductile iron. However, medium carbon steels may have tensile strengths of 
up to 220 ksi. Thus, a matrix of low alloy steel will have approximately 
twice the strength of a comparable cast iron product. Furthermore, the 
hardness of heat treated, low alloy steel casting would be between 40 and 
50 R.sub.c versus 38 R.sub.c for ductile iron. 
However, wear-resistant bodies produced by either the molten-steel or the 
molten-cast iron casting methods are often not suitable when used solely 
as a stand-alone product because their high cost and brittleness. Instead, 
the wear-resistant body may be more cost effective when used to increase 
the wear-performance of a larger steel casting in which it is 
incorporated. 
It has been relatively easy to incorporate wear resistant bodies produced 
by the molten-cast iron method into larger steel castings. For example, 
U.S. Pat. No. 4,584,020, issued to Waldenstrom, discloses a technique for 
incorporating a wear resistant molten-cast iron and carbide insert in a 
larger steel casting. The technique consists of applying between the 
casted steel alloy and the wear resistant insert a layer or zone of 
another metallic material with a higher toughness than the cast alloy. 
Generally the metallic material also has a higher melting point than the 
cast alloy and preferably at least 200 to 400 degrees C. (360 degrees F. 
to 720 degrees F.) above the melting point of the cast alloy. The metallic 
material is formed from a low carbon steel having a carbon content of 0.2% 
at the most. The thickness of the sheet of low carbon steel is at least 
0.5 mm and preferably 1 to 8 mm. 
Unfortunately, problems have arisen when attempting to incorporate 
molten-steel wear resistant bodies in larger castings. Several approaches 
have been tried to overcome these problems. E. L. Furman et al 
("Reinforcing Steel Castings With Wear-Resisting Cast Iron," Liteinoe 
Proizvodstvo, No. 7, p.27 (1986)) found that wear resistant bodies could 
be successfully incorporated into larger steel castings when the steel was 
poured at between 1450 to 1480 degrees C. (2642 to 2696 degrees F.). 
However, when the steel pouring temperature was raised above 1500 degrees 
C. (2732 degrees F.) it caused hot tearing and shrinkage blow holing 
inside the wear resistant inserts. Furman found that more effective 
reinforcement could be achieved by coating the inserts with a low melting 
brazing alloy, such as pure copper, prior to pouring the mold. Upon 
pouring, the copper brazing alloy melts and wets the surfaces of the 
inserts and the poured steel. A suitable fluxing agent was incorporated to 
prevent oxidation of the inserts during pouring. 
U.S. Pat. No. 4,608,318, issued to Makrides et al discloses a tough, wear 
resistant composite. Carbide particles and a stainless steel metallic 
matrix are first formed into a wear-resistant insert by powder 
metallurgical methods including blending the powders, isostatically 
compacting the blend, and consolidating to form the insert. A second 
metallic matrix of molten metal is then bonded to the wear-resistant 
insert to complete the composite. The second metallic matrix formed by the 
molten metal may be a ferrous or non-ferrous alloy and is preferably 
steel. 
Another powder metallurgical approach to this problem is disclosed in 
Australian Patent No. AU-B1-31362/77. According to the background 
discussion in U.S. Pat. No. 4,608,318, the Australian reference teaches 
milling a heat treatable low alloy steel powder together with a tungsten 
carbide or tungsten molybdenum solid solution carbide powder and then 
pressing and sintering to form the wear-resistant insert. Low alloy steel 
is then cast about the sintered wear-resistant insert to form the finished 
composite. 
Certain disadvantages become apparent with the prior art. First, the 
technique as taught by Furman requires the additional step of coating the 
individual inserts. This method not only increases the cost of the final 
composite body but also creates an additional interface which may result 
in a later failure. Second, the powder metallurgical methods taught by 
Makrides and also Australian patent No. AU-B1-31362/77 are significantly 
more costly due to the necessary steps of preparing milled powders, 
blending, and isostatically pressing to form the insert. 
It has thus become desirable to develop a wear-resistant cast 
"carbide/ferrous composite" insert having the strength and hardness 
advantages achieved by using a molten steel casting alloy or a molten cast 
iron and, at the same time, eliminating the prior art problems of hot 
tearing and shrinkage when the wear resistant body is incorporated into a 
larger steel casting. 
SUMMARY OF THE INVENTION 
The present invention solves the aforementioned problems associated with 
the prior art by providing an improved tough, wear-resistant cast "carbide 
ferrous matrix composite" insert formed by a molten ferrous casting 
process. The wear resistant body may be subsequently incorporated into a 
larger steel casting and which will form a strong, metallurgical bond with 
the steel matrix of the larger casting without hot tearing or shrinkage 
blow holing inside the inserts. The wear-resistant inserts are made by a 
casting process in which casted ferrous matrix material having a melting 
point of between 2100 and 2600 degrees F. is combined with particles or 
compacts of sintered tungsten carbide or similar hard carbides. The insert 
is then placed into a suitable mold into which steel of a melting point of 
between 2700 and 2800 degrees F. is poured. The casted steel 
metallurgically bonds to the insert to form a composite structure. The 
fusion is facilitated by the fact that the melting temperature of the 
ferrous matrix alloy used for preparing the wear-resistant insert is lower 
than the melting temperature of the casted steel. In addition, the use of 
a separate wear-resistant insert allows a variety of concentrations, 
positions, and orientations of the carbide particles both on the surface 
and beneath surface of the low alloy substrate, thereby allowing the 
physical properties of the composite to be tailored for specific 
applications. 
Accordingly, one aspect of the present invention is to provide a tough, 
wear resistant body including a hard carbide material and a casted ferrous 
matrix material, wherein the carbide material is embedded in and bonded to 
the casted ferrous matrix. 
Another aspect of the present invention is to provide a tough, wear 
resistant composite body including a hard carbide material and a first 
casted ferrous matrix material form into a wear resistant body and a 
second steel matrix, wherein the wear resistant body is embedded in and 
bonded to the second steel matrix. 
Still another aspect of the present invention is to provide a method of 
forming a tough, wear resistant composite body including the steps of 
positioning a plurality of hard carbide particles within a first mold, 
separately melting a first ferrous matrix material and casting the first 
ferrous matrix into the mold to form a wear resistant body, positioning 
the wear resistant body within a second mold, and separately melting a 
second steel matrix and casting the second steel matrix into the second 
mold, wherein the wear resistant body is embedded in and bonded to the 
second steel matrix. The first ferrous matrix material may be either steel 
or cast iron. 
These and other aspects of the present invention will become apparent to 
those skilled in the art after a reading of the following description of 
the preferred embodiment when considered with the drawings.

DESCRIPTION OF THE PREFERRED EMBODIMENT 
In the following description, like references characters designate like or 
corresponding parts throughout the several views. Also in the following 
description, it is to be understood that such terms as "forward", 
"rearward", "left", "right", "upwardly", "downwardly", and the like are 
words of convenience and are not to be construed as limiting terms. 
Referring now to the drawings in general and to FIG. 1 in particular, it 
will be understood that the illustrations are for the purpose of 
describing a preferred embodiment of the invention and are not intended to 
limit the invention thereto. As best seen in FIG. 1, there is partially 
shown the lower lip 10 of a conventional excavator bucket 12 such as may 
be employed on a backhoe or front-end loader. A tooth support 14 is welded 
or otherwise attached to lip 10. Excavator tooth 16 is secured to tooth 
support 14 by any of a number of conventional attachment means 20, 
including bolts or pins. Excavator tooth 16 includes a recessed portion 
(see FIG. 2) for receiving the elongated portion of tooth support 14. The 
tooth support 14 is normally composed of a conventional, heat treatable 
medium carbon alloy steel such as AISI 4330 or commonly used modifications 
thereof. 
Turning now to FIG. 2, a vertical sectional view of the excavator tooth 16 
shown in FIG. 1 is illustrated. Excavator tooth 16 is a composite 
structure comprising a cast "low C" carbon alloy 22 and a cast steel 
"carbide/steel composite", or cast "carbide/cast iron composite" wear 
resistant insert 24. It is to be understood that in the following 
description "low C" refers to a carbon content of less than 1 wt. % and 
"high C" refers to a carbon content of at least 0.85 wt %. In addition, 
the term "carbon equivalent" is defined as equal to the sum of the carbon 
content wt. % plus 0.3 times the sum of the silicon and phosphorus wt. %. 
The "low C" substrate 22 may be composed of an air-hardening Ni-Cr-Mo or 
Si-Mn-Ni-Cr-Mo low alloy steel material having a melting point of about 
2700 degrees F. but preferably is a typical heat treatable medium carbon 
alloy steel such as AISI 4330 and its common modifications which have been 
used in the prior art for tooth support 14. Preferably, the carbon content 
of the substrate composition is nominally 0.25% to 0.35% carbon. The cast 
alloy of substrate 22 typically has a heat treated hardness range of 
between 40 and 50 R.sub.c. 
Prior to pouring the "low C" substrate 22, the cast ferrous matrix wear 
resistant insert 24 is first positioned within a mold. Preheating of the 
cast ferrous matrix wear resistant insert 24 is not required prior to 
pouring of the molten metal into the mold. The pouring temperature of the 
cast alloy substrate 22 is about 2950 to 3050 degrees F. After pouring, 
the excavator tooth 16 is allowed to cool and then is shaken out of the 
mold and heat treated to the desired hardness. 
Turning to FIG. 3, an enlarged cross-sectional view of the cast ferrous 
wear-resistant insert 24 is shown. Wear resistant insert 24 includes one 
or more layers of hard carbide particulate 26. The carbide particulate 26 
is typically composed of irregularly shaped particles of from 4 mesh to 
3/8 inch in size. However, particles of finer than 4 mesh or larger than 
3/8 inch having either regular or irregular shapes may be used. The 
carbide particulate 26 is preferably a cobalt cemented tungsten carbide 
which may contain tantalum, titanium, and/or niobium. Other hard carbides 
may also be used and may be selected from the group consisting of tungsten 
carbide (eutectic cast tungsten carbide or macrocrystalline tungsten 
carbide), titanium carbide, tantalum carbide, niobium carbide, zirconium 
carbide, vanadium carbide, hafnium carbide, molybdenum carbide, chromium 
carbide, boron carbide, silicon carbide, their mixtures, solid solutions, 
and cemented composites. 
The "high C" cast ferrous matrix material may be an alloy steel, such as an 
austenitic manganese alloy steel, a ferrite alloy steel or a cast iron. 
For example, an alloy steel having a melting point of about 2400 to 2600 
degrees F. and, preferably, 1.0 to 2.5% carbon equivalent, is cast about 
the carbide particulate 26 and allowed to cool to form the matrix 30 of 
wear-resistant insert 24. In yet another example of the present invention, 
cast iron having a melting point of approximately 2100 to 2400 degrees F. 
may be cast about the carbide particulate 26 and allowed to cool to form 
the matrix 30 of wear-resistant insert 24. The casting procedure used may 
be any of those well-known to those skilled in the art. However, it is 
preferred that the casting procedure disclosed in detail in the Baum U.S. 
Pat. Nos. 4,024,902 and 4,146,080 be used. The entire disclosure of these 
patents are incorporated herein by reference. 
As discussed above, after cooling, the wear-resistant insert 24 is placed 
inside a mold cavity (not shown) for the excavator tooth 16. The "low C" 
carbon content molten steel 22 is poured into the mold cavity which 
contains the insert 24. The "low C" molten steel 22 flows about and 
envelopes the insert 24 and a strong, metallurgical bond is achieved 
between the insert 24 and the poured steel 22. The metallurgical bond is 
facilitated by the fact that the melting point of "high C" matrix 30 of 
the wear-resistant insert 24 is considerably lower than that of the "low 
C" molten steel being poured, preferably at least 200 to 300 degrees F. 
lower. As a result, some melting will occur at the surface of insert 24. 
This molten surface layer fuses readily with the "low C" steel 22 being 
poured and a sound bond is obtained after solidification has taken place. 
On the contrary, it has been shown that if the wear resistant inserts 24 
are made with a "low C" carbon steel, bonding with the "low C" steel 22 
being poured does not occur because the melting points of both materials 
are essentially the same and therefore the amounts of superheat is not 
sufficient to melt the first ferrous matrix. Thus, the wear-resistant 
insert 24 must have a melting point lower than that of the substrate 22, 
since the relative difference in melting points is a key factor 
responsible for achievement of a metallurgical bond between the insert 24 
and the substrate 22. 
The process and products according to the present invention will become 
more apparent upon reviewing the following detailed examples. 
EXAMPLE NO. 1 
A number of wear and impact resistant excavator teeth having a 
wear-resistant insert embedded therein were fabricated. A mixture of 
cobalt cemented tungsten carbide having 4 mesh to 3/8 inch particles were 
placed in a sand mold having multiple recesses corresponding roughly to 
the desired dimensions of the insert. For this particular application, the 
individual inserts were 1 inch by 4 inches and 3/4 inches deep. The amount 
of carbide particulate chosen was such that at least one layer of carbide 
particles covered the bottom of each recess. A "high C" carbon content 
steel having about 1.8 wt. % C and a total carbon equivalent value of 2.4 
was melted and cast at between 2850 and 2950 degrees F. about the tungsten 
carbide particulate. The nominal composition of the steel was 1.8% C, 2.0% 
Si, 0.5% Mn, 1% Mo, typical impurities, and the remainder Fe. The molds 
were preheated to between 1500 and 1800 degrees F. prior to casting. Upon 
cooling, the insert castings were removed from the sand mold and placed 
inside of a second sand mold having a recess formed to the required 
excavator tooth shape. The ingredients to produce a "low C" carbon content 
steel alloy were melted in a induction furnace, the molds were not 
preheated, and the "low C" steel was cast into the mold at between 3050 
degrees to 3100 degrees F. to form the excavator tooth 16 shown in FIGS. 1 
and 2. The nominal composition of the "low C" steel was 0.3% C, 1.5% Si, 
1.0% Mn, 1.0% Ni, 2.0% Cr, 0.35% Mo, typical impurities, and the remainder 
Fe. The tooth was then heat treated by normalizing at about 1750 degrees 
F. for approximately 3 hours and then air cooled. The tooth was then 
austenitized at 1650 degrees F. for approximately 3 hours, water quenched, 
and tempered at 400 degrees F. for a minimum of 3 hours. 
A visual examination disclosed that the higher melting point "low C" steel 
caused a portion of the surface of the wear-resistant insert, having a 
higher carbon equivalent matrix, to melt. The examination also indicated 
that the molten surface layer fused readily with the "low C" steel being 
poured and that a sound bond had been obtained. 
Hardness measurements of a section of the cast excavator tooth showed 
hardness values in the range of 35 to 45 R.sub.c and 45 to 50 R.sub.c 
within a traverse of the "high C" steel matrix and the "low C" 
air-hardened steel, respectively. 
EXAMPLE NO. 2 
Another group of wear and impact resistant excavator teeth having a 
wear-resistant insert embedded therein were fabricated. A mixture of 
cobalt cemented tungsten carbide having 4 mesh to 3/8 inch particles were 
placed in a sand mold having multiple recesses corresponding to the 
dimensions of the insert. For this application, the individual inserts 
were again 1 inch by 4 inches and 3/4 inches deep. The amount of carbide 
particulate chosen was such that at least one layer of carbide particles 
covered the bottom of each recess. A "low C", low alloy steel having a 
total carbon equivalent value of about 0.6 was melted and cast at about 
3150 degrees F. about the tungsten carbide particulate. The nominal 
composition of the "low C" steel was 0.3% C, 1.0% Si, 0.5% Mn, 4.0% Ni, 
1.4% Cr, 0.25% Mo, typical impurities, and the remainder Fe. The molds 
were preheated to between 1500 and 1800 degrees F. prior to casting. Upon 
cooling, the insert castings were removed from the sand mold and placed 
inside of a second sand mold having a recess formed to the required 
excavator tooth shape. The ingredients to produce the same "low C" steel 
alloy as used for the substrate 22 in Example No. 1 were melted in a 
induction furnace, the molds were not preheated, and the steel was cast 
into the mold at between 3050 degrees to 3100 degrees F. to form the 
excavator tooth 16 shown in FIGS. 1 and 2. No heat treatment was 
performed. 
EXAMPLE NO. 3 
A number of wear and impact resistant excavator teeth having a 
wear-resistant insert embedded therein were fabricated. A mixture of 
cobalt cemented tungsten carbide having 4 mesh to 3/8 inch particles were 
placed in a sand mold having multiple recesses corresponding roughly to 
the desired dimensions of the insert. For this particular application, the 
individual inserts were 2 inches by 4 inches and 3/4 inches deep. The 
amount of carbide particulate chosen was such that at least one layer of 
carbide particles covered the bottom of each recess. A "high C" ferrous 
austenitic alloy having about 3.8 wt. % C and a total carbon equivalent 
value of 4.4 was melted in an induction furnace and cast at about 2700 
degrees F. about the tungsten carbide particulate. The nominal composition 
of the ferrous alloy was 3.8% C, 1.9% Si, 0.2% Mn, 11.3% Ni and 1.5% W, 
typical impurities and the remainder Fe. The molds were preheated to 
between 1500 and 1800 degrees F. prior to casting. Upon cooling, the 
insert castings were removed from the sand mold and placed inside of a 
second sand mold having a recess formed to the required excavator tooth 
shape. The ingredients to produce a "low C" carbon content steel alloy 
were melted in an induction furnace, the molds were not preheated, and the 
"low C" steel was cast into the mold at 3025 degrees F. to form the 
excavator tooth 16 shown in FIGS. 1 and 2. The nominal composition of the 
"low C" steel was 0.3% C, 1.5% Si, 1.5% Mn, 1.5% Ni, 0.8% Cr, 0.3% Mo, 
typical impurities and the remainder Fe. 
A visual examination disclosed that the higher melting point "low C" steel, 
being poured at 3025 degrees F., caused a portion of the surface of the 
wear-resistant insert, having higher carbon equivalent matrix, to melt. 
The melting point of the insert matrix alloy was estimated to be between 
about 2150 and 2250 degrees F. The examination also indicated that the 
molten surface layer fused readily with the "low C" steel being poured and 
that a sound bond had been obtained. 
EXAMPLE 4 
A number of wear and impact resistant excavator teeth having a 
wear-resistant insert embedded therein were fabricated. A mixture of 
cobalt cemented tungsten carbide having 4 mesh to 3/8 inch particles were 
placed in a sand mold having multiple recesses corresponding roughly to 
the desired dimensions of the insert. For this particular application, the 
individual inserts were 1 inch by 4 inches and 3/4 inches deep. The amount 
of carbide particulate chosen was such that at least one layer of carbide 
particles covered the bottom of each recess. A "high C" ferrous alloy 
having about 3.1 wt. % C and a total carbon equivalent value of 3.6 was 
melted in an induction furnace and cast at approximately 2780 degrees F. 
about the tungsten carbide particulate. The nominal composition of the 
ferrous alloy was 3.1% C, 1.4% Si, 0.3% Mn, 1.7% Ni, 0.6% Cr, 3.6% W, 
typical impurities and the remainder Fe. The molds were preheated to 
between 1500 and 1800 degrees F. prior to casting. Upon cooling, the 
insert castings were removed from the sand mold and placed inside of a 
second sand mold having a recess formed to the required excavator tooth 
shape. The ingredients to produce a "low C" carbon content steel alloy 
were melted in an induction furnace, the molds were not preheated, and the 
"low C" steel was cast into the mold at approximately 3100 degrees F. to 
form the excavator tooth 16 shown in FIGS. 1 and 2. The nominal 
composition of the "low C" steel was 0.3% C, 1.5% Si, 1.5% Mn, 1.5% Ni, 
0.8% Cr, 0.3% Mo, typical impurities and the remainder Fe. 
A visual examination disclosed that the higher melting point "low C" steel, 
being poured at 3100 degrees F., caused a portion of the surface of the 
wear-resistant insert, having higher carbon equivalent matrix, to melt. 
The melting point of the insert matrix alloy was estimated to be between 
about 2250 and 2350 degrees F. The examination also indicated that the 
molten surface layer fused readily with the "low C" steel being poured and 
that a sound bond had been obtained. 
One of the teeth was then heat treated by austenitizing at about 1750 
degrees F. for approximately 3 hours followed by water quenching to room 
temperature, and tempering at about 400 degrees F. for approximately 4 
hours. No evidence of cracking was observed in the wear-resistant inserts 
contained in the heat treated excavator tooth. 
EXAMPLE 5 
A steel casting of a rectangular bar shape incorporating wear-resistant 
austenitic manganese steel/carbide composite insert castings along one 
corner of the bar was produced. The cross-section of each individual 
insert castings was of a right-triangle, with dimensions of approximately 
11/4 inches by 11/4 inches by 13/4 inches and of a length of approximately 
3 inches. 
The triangular bar shaped insert castings were made of a mixture of cobalt 
cemented tungsten carbide having 4 mesh to 3/8 inch particles positioned 
in a sand mold having multiple recesses corresponding roughly to the 
desired dimensions of the insert. The amount of carbide particulate chosen 
was such that at least one layer of carbide particles covered the bottom 
of the two 11/4 inch wide surfaces of the right triangle of each recess. 
An austenitic manganese steel alloy having approximately 0.9 wt % C and a 
carbon equivalent value of 1.2 was melted in an induction furnace and cast 
at 3050 degrees F. about the tungsten carbide particulate. The nominal 
composition of the austenitic manganese steel alloy was 0.9%, C, 13.5% Mn, 
1.1% Si, 1.1% Mo, typical impurities and the remainder Fe. The mold 
containing the carbide particulate was preheated to between 1500 degrees 
F. and 1800 degrees F. prior to casting. Upon cooling, the composite 
insert castings were removed from the sand mold and placed inside of a 
second sand mold of a rectangular bar shape having a recess which measured 
41/2 inches by 7 inches by 3 inches. Two of the insert castings were 
placed in an end to end relationship along the 7 inch wide side of the 
bottom corner of the recess with the carbide containing surfaces of the 
composite insert castings facing outward against the sand. The ingredients 
to produce a "low C" steel were melted in an induction furnace. The mold 
was not preheated and the "low C" steel was cast into the mold at 
approximately 2950 degrees F. to form the composite casting. The nominal 
composition of the "low C" steel was 0.45% C, 0.75% Mn, 0.50% Si, 2.0% Cr, 
0.45% Mo, typical impurities and the remainder Fe. 
It will be appreciated that one possible application for the resultant wear 
resistant composite casting in the form of a rectangular block including a 
casted insert of the shape described above along the length of one corner 
of the block is in mineral crushing hammers. 
A visual examination of a cross-section of the casting disclosed that the 
"low C" steel being poured at 2950 degrees F. caused a portion of the 
surface of the higher carbon equivalent insert matrix alloy (austenitic 
manganese steel) to melt. The melting point of the insert matrix alloy was 
estimated to be between 2500 and 2600 degrees F. The examination also 
indicated that a sound fusion bond had been obtained between the insert 
matrix alloy and "low C" steel which comprised the body of the casting. 
A visual examination disclosed that the substantially equal melting points 
of "low C" and the low alloy steel did not cause the surface of the 
wear-resistant insert, having a substantially equal carbon equivalent 
matrix, to melt. The examination also indicated that a sound bond was not 
obtained. 
Certain modifications and improvements will occur to those skilled in the 
art upon reading of the foregoing description. It should be understood 
that all such modifications and improvements have been deleted herein for 
the sake of conciseness and readability but are properly within the scope 
of the following claims.