Fuel-oxidant mixture for detonation gun flame-plating

The invention relates to a fuel-oxidant mixture for detonation gun applications comprising an oxidant such as oxygen and a fuel mixture of two combustible gases such as acetylene and propylene. The invention also relates to articles coated in a process using this fuel-oxidant mixture.

DESCRIPTION OF THE PREFERRED EMBODIMENTS 
As stated above, acetylene is considered to be the best combustible fuel 
for detonation gun operations since it produces both temperatures and 
pressures greater than those obtainable from any other saturated or 
unsaturated hydrocarbon. To reduce the temperature of the reaction 
products of the combustible gas, nitrogen or argon was generally added to 
dilute the oxidant-fuel mixture. This had the disadvantage of lowering the 
pressure of the detonation wave thus limiting the achievable particle 
velocity. Unexpectedly, it was discovered that when a second combustible 
gas, such as propylene, is mixed with acetylene, the reaction of the 
combustible gases with an appropriate oxidant yields a peak pressure at 
any temperature that is higher than the pressure of an equivalent 
temperature nitrogen diluted acetylene-oxygen mixture. If, at a given 
temperature, an acetylene-oxygen-nitrogen mixture is replaced by an 
acetylene-second combustible gas-oxygen mixture, the gaseous mixture 
containing the second combustible gas will always yield higher peak 
pressure than the acetylene oxygen-nitrogen mixture. 
The theoretical values of RP% and RT% are defined as follows: 
RP%=100 (P.sub.D /P.sub.o) 
RT%=100 .DELTA.T.sub.D /.DELTA.T.sub.o. 
P.sub.o and .DELTA.T.sub.o are respectively the pressure and temperature 
rise following the detonation of a 1:1 mixture of oxygen and acetylene 
from the following equation: 
EQU C.sub.2 H.sub.2 +O.sub.2 .fwdarw.2 CO+H.sub.2. 
P.sub.D and .DELTA.T.sub.D are, respectively, the pressure rise and 
temperature rise following the detonation of either an oxygen-acetylene 
mixture diluted with nitrogen or an acetylene-second hydrocarbon 
gas-oxygen mixture where the ratio of carbon to oxygen is 1:1. 
Different temperatures are achieved by using different values for either X 
or Y in the following equations: 
##STR1## 
The values of RP% versus RT% for the detonation of either an 
oxygen-acetylene mixture diluted with nitrogen or an acetylene second 
hydrocarbon-oxygen mixture are shown in the drawing figure. As evident 
from the drawing figure, as one adds N.sub.2, as in Equation 2a, to lower 
the value of .DELTA.T.sub.D and hence RT%, the peak pressure P.sub.D and 
hence RP%, is also decreased. For example, if sufficient nitrogen is added 
to reduce .DELTA.T.sub.D to 60% of .DELTA.T.sub.o, the peak pressure 
P.sub.D drops to 50% of P.sub.o. If, however, an acetylene-second 
hydrocarbon oxygen mixture is used for any value of .DELTA.TD or RT%, the 
value of P.sub.D and hence RP% will be larger than if a nitrogen diluted 
acetylene oxygen mixture is used. For example, as shown in FIG. 1, if an 
acetylene-propylene oxygen mixture is used to obtain a value of RT% equal 
to 60%, the ratio of RP% is 80%, a value 1.6 times greater than if an 
acetylene-oxygen-nitrogen mixture is employed to achieve a value of RT% 
equal to the same value. It is believed that higher pressures increase 
particle velocity, which results in improved coating properties. 
For most applications the gaseous fuel-oxidant mixture of this invention 
could have an atomic ratio of oxygen to carbon of from about 0.9 to about 
2.0, preferably from about 0.95 to about 1.6 and most preferably from 
about 0.98 to 1.4. An atomic ratio of oxygen to carbon below 0.9 would 
generally be unsuitable because of the formation of free carbon and soot 
while a ratio above 2.0 would generally be unsuitable for carbide and 
metallic coatings because the flame becomes excessively oxidizing. 
In a preferred embodiment of the invention the gaseous fuel-oxidant mixture 
would comprise from 35 to 80 percent by volume oxygen, from 2 to 50 
percent by volume acetylene and 2 to 60 percent by volume of a second 
combustible gaseous fuel. In a more preferable embodiment of the invention 
the gaseous fuel-oxidant mixture would comprise from 45 to 70 percent by 
volume oxygen, from 7 to 45 percent by volume acetylene and 10 to 45 
percent by volume of a second combustible fuel. In another more preferable 
embodiment of the invention the gaseous fuel-oxidant mixture would 
comprise from 50 to 65 percent by volume oxygen, from 12 to 26 percent by 
volume acetylene and 18 to 30 percent by volume of a second combustible 
gaseous fuel such as propylene. In some applications, it may be desirable 
to add an inert diluant gas to the gaseous fuel oxidant mixture. Suitable 
inert diluting gases would be argon, neon, krypton, xenon, helium and 
nitrogen. 
Generally, all prior art coating materials that could be employed with the 
fuel-oxidant mixture of the prior art in detonation gun applications can 
be used with the novel gaseous fuel-oxidant mixture of this invention. In 
addition, the prior art coating compositions, when applied at lower 
temperatures and higher pressures than that of the prior art, produce 
coatings on substrates that have conventional compositions but novel and 
unobvious physical characteristics such as hardness. Examples of suitable 
coating compositions for use with the gaseous fuel oxidant mixture of this 
invention would include tungsten carbide-cobalt, tungsten carbide nickel, 
tungsten carbide-cobalt chromium, tungsten carbide-nickel chromium, 
chromium-nickel, aluminum oxide, chromium carbide nickel chromium, 
chromium carbide-cobalt chromium, tungsten titanium carbide nickel, cobalt 
alloys, oxide dispersion in cobalt alloys, alumina-titania, copper based 
alloys, chromium based alloys, chromium oxide, chromium oxide plus 
aluminum oxide, titanium oxide, titanium plus aluminum oxide, iron based 
alloys, oxide dispersed in iron based-alloys, nickel, nickel based alloys, 
and the like. These unique coating materials are ideally suited for 
coating substrates made of materials such as titanium, steel, aluminum 
nickel, cobalt, alloys thereof and the like. 
The powders for use in the D-Gun for applying a coating according to the 
present invention are preferably powders made by the cast and crushed 
process. In this process the constituents of the powder are melted and 
cast into a shell shaped ingot Subsequently, this ingot is crushed to 
obtain a powder which is then screened to obtain the desired particle size 
distribution. 
However, other forms of powder, such as sintered powders made by a 
sintering process, and mixes of powders can also be used. In the sintering 
process, the constituents of the powder are sintered together into a 
sintered cake and then this cake is crushed to obtain a powder which is 
then screened to obtain the desired particle size distribution. 
Some examples are provided below to illustrate the present invention. In 
these examples, coatings were made using the following powder compositions 
shown in Table 1. 
TABLE 1 
__________________________________________________________________________ 
Coating Material Powders 
Powder Size 
Sample Composition - wt % % thru 
Max. % of 
Powder Co C Fe Other 
W Mesh* 
Min. size 
__________________________________________________________________________ 
A 9.0 to 
4.3 to 
1.5 
.21 Bal. 
95% thru 
10% less 
Cast & 10.0 
4.8 max 
max 325 than 5 
Crushed microns 
B 11 to 
5.15 0.5 
0.5 Bal. 
98% thru 
15% less 
Sintered 
13 min. max 
max 325 than 15 
microns 
C 10.5 to 
4.5 to 
1.25 
1.0 Bal. 
98% thru 
15% less 
Mix of Cast 
12.5 
4.8 max 
max 325 than 5 
& Crushed & microns 
Sintered 
D 10 to 
3.9% to 
2.0 
0.2 Bal. 
98% thru 
10% less 
Cast & 12 4.3 max 
max 325 than 5 
Crushed microns 
__________________________________________________________________________ 
*U.S. Standard Mesh size. 
EXAMPLE 1 
The gaseous fuel-oxidant mixtures of the compositions shown in Table 2 were 
each introduced to a detonation gun to form a detonatable mixture having 
an oxygen to carbon atomic ratio as shown in Table 2. Sample coating 
powder A was also fed into the detonation gun. The flow rate of each 
gaseous fuel-oxidant mixture was 13.5 cubic feet per minute (cfm) except 
for samples 28, 29 and 30 which were 11.0 cfm, and the feed rate of each 
coating powder was 53.3 grams per minute (gpm) except for sample 29 which 
was 46.7 gpm and sample 30 which was 40.0 gpm. The gaseous fuel mixture in 
volume percent and the atomic ratio of oxygen to carbon for each coating 
example are shown in Table 2. The coating sample powder was fed into the 
detonation gun at the same time as the gaseous fuel-oxidant mixture. The 
detonation gun was fired at a rate of about 8 times per second and the 
coating powder in the detonation gun was impinged onto a steel substrate 
to form a dense, adherent coating of shaped microscopic leaves 
interlocking and overlapping with each other. 
The percent by weight of the cobalt and carbon in the coated layer were 
determined along with the hardness for the coating. The hardness of most 
of the coating examples in Table 2 were measured as the Rockwell 
superficial hardness and converted into Vickers hardness. The Rockwell 
superficial hardness method employed is per ASTM standard method E 18. The 
hardness is measured on a smooth and flat surface of the coating itself 
deposited on a hardened steel substrate. The Rockwell hardness numbers 
were converted into Vickers hardness numbers by the following formula: 
HV.3=-1774+37.433 HR45N where HV.3 is the Vickers hardness obtained with 
0.3 kgf load and HR45N is the Rockwell superficial hardness obtained on 
the N scale with a diamond penetrator and a 45 kgf load. The hardness of 
the coatings of line 28, 29 and 30 was measured directly as Vickers 
hardness. The Vickers hardness method employed is measured essentially per 
ASTM standard method E 384, with the exception that only one diagonal of 
the square indentation was measured rather than measuring and averaging 
the lengths of both diagonals. A load of 0.3 kgf was used (HV.3). These 
data are shown in Table 2. The values shows that the hardness was superior 
for coatings obtained using propylene in place of nitrogen in the gaseous 
fuel mixture. 
Erosion is a form of wear by which material is removed from a surface by 
the action of impinging particles. The particles are generally solid and 
carried in either a gaseous or a fluid stream, although the particles may 
also be fluid carried in a gaseous stream. 
There are a number of factors which influence the wear by erosion. Particle 
size and mass, and their velocity are obviously important because they 
determine the kinetic energy of the impinging particles. The type of 
particles, their hardness, angularity and shape, and their concentration 
may also affect the rate of erosion. Furthermore, the angle of particle 
impingement will also affect the rate of erosion. For test purposes, 
alumina and silica powders are widely used. 
The test procedure similar to the method described in ASTMG 76-83 was used 
to measure the erosion wear rate of the coatings presented in the 
examples. Essentially, about 1.2 gm per minute of alumina abrasive is 
carried in a gas stream to a nozzle which is mounted on a pivot so that it 
can be set for various particle impingement angles while a constant 
standoff is maintained. It is standard practice to test the coatings at 
both 90.degree. and 30.degree. impingement angles. 
During the test, the impinging particles create a crater on the test sample 
The measured scar depth of the crater is divided by the amount of abrasive 
which impinged on the sample. The results, in micrometers (microns) of 
wear per gram of abrasive, is taken as the erosion wear rate (.mu./gm). 
These data are also shown in Table 2. 
The hardness and erosion wear data show that using an acetylene hydrocarbon 
gas oxygen mixture in place of a nitrogen diluted acetylene-oxygen mixture 
can produce a coating having a higher hardness at the same cobalt content 
(compare sample coating 9 with sample coatings 22 and 23) or higher cobalt 
content at the same hardness (compare sample coating 1 with sample coating 
22). 
TABLE 2 
__________________________________________________________________________ 
D-GUN AMETERS AND PROPERTIES OF COATINGS 
MADE FROM POWDER A 
Gaseous Fuel-Mixture 
Hardness.sup.(1) 
Erosion 
Sample 
(Vol %) O.sub.2 to C 
Vickers 
Chemistry 
(.mu./gm) 
Coating C.sub.2 H.sub.2 
O.sub.2 
Atomic Ratio 
(kg/mm.sup.2) 
% Co 
% C 
90.degree. 
30.degree. 
__________________________________________________________________________ 
C.sub.3 H.sub.6 
1 37.0 
3.7 
59.3 
1.0 1130 19.1 
3.5 
116 22 
2 29.8 
12.8 
57.4 
1.0 1185 17.0 
3.1 
103 20 
3 29.8 
10.0 
60.2 
1.1 1185 15.6 
2.3 
85 20 
4 29.8 
7.5 
62.7 
1.2 1160 14.3 
1.8 
94 21 
5 29.8 
5.3 
64.9 
1.3 1145 13.3 
1.6 
92 22 
6 29.8 
3.2 
67.0 
1.4 1135 12.8 
1.3 
90 22 
7 25.6 
18.0 
56.4 
1.0 1225 16.7 
3.5 
94 19 
8 25.6 
16.6 
57.8 
1.05 1210 14.1 
2.8 
90 20 
9 25.6 
15.3 
59.1 
1.1 1225 13.6 
2.1 
82 19 
10 25.6 
12.9 
61.5 
1.2 1190 12.8 
1.6 
78 21 
11 25.6 
10.6 
63.8 
1.3 1185 11.4 
1.4 
75 20 
12 25.6 
8.6 
65.8 
1.4 1160 11.0 
1.2 
79 23 
13 25.6 
6.7 
67.7 
1.5 1145 10.6 
1.0 
81 24 
14 25.6 
5.7 
68.7 
1.6 1120 10.7 
1.0 
84 25 
15 25.6 
3.4 
71.0 
1.7 1110 10.3 
0.9 
94 26 
16 18.6 
26.7 
54.7 
1.0 1220 14.2 
3.6 
104 23 
17 18.6 
24.1 
57.3 
1.1 1240 11.3 
2.2 
87 24 
18 18.6 
21.8 
59.6 
1.2 1180 10.1 
1.6 
81 21 
19 18.6 
17.6 
63.8 
1.4 1195 8.0 0.9 
74 20 
20 18.6 
14.1 
67.3 
1.6 1110 7.8 0.6 
95 26 
21 18.6 
11.1 
70.3 
1.8 1095 7.9 0.6 
122 28 
N.sub.2 
22 45 27.8 
27.2 
0.98 1140 13.6 
3.6 
94 20 
23 45 27.5 
27.5 
1.0 1030 13.6 
3.5 
90 18 
24 45 25.0 
30.0 
1.2 1009 11.4 
2.1 
77 16 
25 45 22.9 
32.1 
1.4 991 11.2 
1.6 
81 22 
26 45 21.2 
33.8 
1.6 883 10.9 
1.2 
94 23 
27 45 19.6 
35.4 
1.8 930 10.6 
1.1 
110 25 
28 40 30.3 
29.7 
0.98 1080* 13.2 
3.5 
106 20 
29 30 35.3 
34.7 
0.98 1150* 10.7 
3.6 
109 18 
30 10 42.8 
42.2 
0.98 1300* 6.8 3.7 
119 20 
__________________________________________________________________________ 
Note (1) measured as Rockwell superficial hardness and converted to 
Vickers hardness unless otherwise indicated by an asterisk (*). 
EXAMPLE 2 
The gaseous fuel-oxidant mixture of the compositions shown in Table 3 were 
each introduced into a detonation gun at a flow rate of 13.5 cubic feet 
per minute to form a detonatable mixture having an atomic ratio of oxygen 
to carbon as also shown in Table 3. The coating powder was Sample A and 
the fuel-oxidant mixture and powder feed rate are as also shown in Table 
3. As in Example 1, the Vickers hardness and erosion rate (.mu./gm) data 
were determined and these data are shown in Table 3. As evidenced from the 
data, various hydrocarbon gases can be used in conjunction with acetylene 
to provide a gaseous fuel-oxidant mixture in accordance with this 
invention to coat substrates. The Vickers hardness data show that using an 
acetylene-hydrocarbon gas oxygen mixture in place of an 
acetylene-oxygen-nitrogen mixture can produce either a coating having a 
higher hardness at the same cobalt content (compare sample coatings 5 and 
10 with sample coating 23 in Table 2) or a coating having a higher cobalt 
content for the same hardness (compare sample coatings 6, 8 and 11 with 
sample coating 22 in Table 2). 
TABLE 3 
__________________________________________________________________________ 
D-GUN AMETERS AND PROPERTIES OF COATINGS 
MADE FROM POWDER A 
Gaseous Fuel-Mixture 
Powder 
Hardness Erosion 
Sample 
(Vol %) O.sub.2 to C 
Feed Rate 
Vickers 
Chemistry 
(.mu./gm) 
Coating C.sub.2 H.sub.2 
O.sub.2 
Atomic Ratio 
(gmp) (kg/mm.sup.2) 
% Co 
% C 
90.degree. 
30.degree. 
__________________________________________________________________________ 
CH.sub.4 
1 12.9 
40.3 
46.8 
1.0 53 1272 9.3 3.6 
93 20 
2 21.2 
34.1 
44.7 
1.0 53 1231 12.6 
3.4 
96 21 
3 27.8 
29.2 
43.0 
1.0 53 1180 15.1 
3.2 
102 21 
C.sub.2 H.sub.4 
4 17.1 
32.9 
50.0 
1.0 53 1270 9.6 3.7 
96 20 
5 29.2 
20.8 
50.0 
1.0 53 1186 13.6 
3.7 
97 21 
6 39.2 
10.8 
50.0 
1.0 53 1160 16.5 
3.8 
103 20 
7 39.2 
10.8 
50.0 
1.0 40 1192 17.3 
3.6 
103 20 
C.sub.3 H.sub.6 
*8 17.1 
19.6 
45.0 
1.0 53 1120 16.2 
3.5 
97 21 
C.sub.3 H.sub.8 
9 7.0 41.2 
51.8 
1 53 1240 9.5 3.8 
112 21 
10 12.3 
34.6 
53.1 
1 53 1196 13.3 
3.8 
99 21 
11 16.8 
29.0 
54.2 
1 53 1140 16.6 
3.7 
106 20 
12 16.8 
29.0 
54.2 
1 40 1161 16.9 
3.6 
102 19 
C.sub.4 H.sub.10 
13 5.7 41.5 
52.9 
1 53 1263 9.5 3.8 
106 19 
__________________________________________________________________________ 
*Sample Coating 8 also contained 18.3 volume percent nitrogen. 
EXAMPLE 3 
The gaseous fuel-oxidant mixture of the compositions shown in Table 4 were 
each introduced into a detonation gun to form a detonatable mixture having 
an atomic ratio of oxygen to carbon as also shown in Table 4. The coating 
powder was sample B and the fuel-oxidant mixture is as also shown in Table 
4. The gas flow rate was 13.5 cubic feet per minute (cfm) with the feed 
rate being as shown in Table 4. As in Example 1, the hardness and erosion 
rate (.mu./gm) were determined and these data are shown in Table 4. While 
sintered powders do not show a great change in cobalt content with gun 
temperature changes, higher hardness coatings with equivalent cobalt 
contents can be obtained with acetylene-hydrocarbon gas-oxygen mixtures 
than with acetylene-oxygen nitrogen mixtures (compare sample coating 4 
with sample coating 1). 
TABLE 4 
__________________________________________________________________________ 
D-GUN AMETERS AND PROPERTIES OF COATINGS 
MADE FROM POWDER B 
Gaseous Fuel-Mixture 
Powder 
Hardness Erosion 
Sample 
(Vol %) O.sub.2 to C 
Feed Rate 
Vickers 
Chemistry 
(.mu./gm) 
Coating C.sub.2 H.sub.2 
O.sub.2 
Atomic Ratio 
(gpm) (Kg/mm.sup.2) 
% Co 
% C 
90.degree. 
30.degree. 
__________________________________________________________________________ 
N.sub.2 
1 45 27.8 
27.2 
0.98 17 940 12.9 
5.2 
2 45 27.8 
27.2 
0.98 25 920 13.1 
5.1 
76 9.5 
C.sub.3 H.sub.6 
3 18.6 
27.3 
54.1 
0.98 17 1070 13.3 
5.1 
82 12 
4 18.6 
27.3 
54.1 
0.98 25 1160 12.9 
5.2 
72 11 
5 25.6 
18.6 
55.8 
0.98 25 1045 13.5 
5.2 
68 9 
6 29.8 
12.8 
57.4 
1.0 25 890 12.7 
4.5 
71 8 
7 37 3.7 
59.3 
1.0 25 935 13.6 
5.2 
86 9 
__________________________________________________________________________ 
EXAMPLE 4 
The gaseous fuel oxidant mixture of the compositions shown in Table 5 were 
each introduced into a detonation gun to form a detonatable mixture having 
an atomic ratio of oxygen to carbon as also shown in Table 5. The coating 
powder was sample C and the fuel oxidant mixture is as also shown in Table 
5. The gas flow rate was 13.5 cubic feet per minute (cfm) with the feed 
rate being as shown in Table 5. As in Example 1, the Vickers hardness and 
erosion rate (.mu./gm) were determined and these data are shown in Table 
5. The Vickers hardness data show that using an acetylene-hydrocarbon 
gas-oxygen mixture in place of an acetylene-oxygen-nitrogen mixture can 
produce a coating having a higher hardness at the same cobalt content 
(compare sample coating 2 with sample coating 1). 
TABLE 5 
__________________________________________________________________________ 
D-GUN AMETERS AND PROPERTIES OF COATINGS 
MADE FROM POWDER C 
Gaseous Fuel-Mixture 
Powder 
Hardness Erosion 
Sample 
(Vol %) O.sub.2 to C 
Feed Rate 
Vickers 
Chemistry 
(.mu./gm) 
Coating C.sub.2 H.sub.2 
O.sub.2 
Atomic Ratio 
(gpm) (Kg/mm.sup.2) 
% Co 
% C 
90.degree. 
30.degree. 
__________________________________________________________________________ 
N.sub.2 
1 45 27.5 
27.5 
1.0 36.7 980 13.4 
4.1 
79 15 
C.sub.3 H.sub.6 
2 18.6 
26.8 
54.7 
1.0 36.7 1168 13.2 
4.1 
87 15 
3 29.8 
12.8 
57.5 
1.0 36.7 1149 15.0 
4.0 
76 13 
4 29.8 
12.8 
57.5 
1.0 53.3 1194 14.7 
4.0 
74 12 
5 29.8 
10.0 
60.2 
1.1 36.7 1129 14.0 
2.9 
74 14 
__________________________________________________________________________ 
EXAMPLE 5 
The gaseous fuel-oxidant mixture of the compositions shown in Table 6 were 
each introduced into a detonation gun to form a detonatable mixture having 
an atomic ratio of oxygen to carbon as also shown in Table 6. The coating 
powder was sample D and the fuel-oxidant mixture is as also shown in Table 
6. The gas flow rate was 13.5 cubic feet per minute (cfm) except for 
sample coatings 17, 18 and 9 which were 11.0 cfm, and the feed rate was 
46.7 grams per minute (gpm). As in Example 1, the Vickers hardness and 
erosion rate (.mu./gm) were determined and these data are shown in Table 
6. The Vickers hardness data show that using an acetylene-hydrocarbon 
gas-oxygen mixture in place of an acetylene-oxygen nitrogen mixture can 
produce either a coating having a higher hardness at the same cobalt 
content (compare sample coating 5 with sample coating 17) or a coating 
having a higher cobalt content for the same hardness (compare sample 
coating 5 with sample coating 18). 
TABLE 6 
__________________________________________________________________________ 
D-GUN AMETERS AND PROPERTIES OF COATINGS 
MADE FROM POWDER D 
Gaseous Fuel-Mixture 
Hardness.sup.(1) 
Erosion 
Sample 
(Vol %) O.sub.2 to C 
Vickers 
Chemistry 
(.mu./gm) 
Coating 
C.sub.3 H.sub.6 
C.sub.2 H.sub.2 
O.sub.2 
N.sub.2 
Atomic Ratio 
(Kg/mm.sup.2) 
% Co 
% C 
90.degree. 
30.degree. 
__________________________________________________________________________ 
1 37.0 
3.7 
59.3 
-- 1.0 17.6 
3.2 
2 29.8 
12.8 
57.4 
-- 1.0 1235 15.2 
2.4 
109 24 
3 29.8 
7.5 
62.7 
-- 1.2 1200 13.2 
0.9 
86 25 
4 29.8 
3.2 
67.0 
-- 1.4 1180 11.6 
0.6 
77 24 
5 25.6 
18.0 
56.4 
-- 1.0 1250 15.5 
3.2 
100 25 
6 25.6 
16.6 
57.8 
-- 1.05 
1230 14.3 
2.1 
88 24 
7 25.6 
15.3 
59.1 
-- 1.1 1185 13.7 
1.6 
81 24 
8 25.6 
12.9 
61.5 
-- 1.2 1110 12.6 
1.0 
75 24 
9 25.6 
10.6 
63.8 
-- 1.3 1215 14.4 
1.3 
81 24 
10 25.6 
8.6 
65.8 
-- 1.4 1020 10.5 
0.7 
7.1 23 
11 25.6 
6.7 
67.7 
-- 1.5 1095 9.9 0.5 
75 25 
12 25.6 
5.7 
68.7 
-- 1.6 1180 9.8 0.5 
84 25 
13 25.6 
3.4 
71.0 
-- 1.7 1115 9.5 0.5 
93 25 
14 18.6 
24.1 
57.3 
-- 1.1 1260 10.0 
1.3 
69 22 
15 18.6 
21.8 
59.6 
-- 1.2 1215 9.3 0.9 
65 22 
16 18.6 
17.6 
63.8 
-- 1.4 920 7.0 0.5 
101 25 
17 -- 30.3 
29.7 
40 0.98 
1100* 15.6 
3.4 
120 30 
18 -- 35.3 
34.7 
30 0.98 
1250* 12.2 
3.5 
120 26 
19 -- 42.8 
42.2 
10 0.98 
1375* 6.9 3.6 
120 23 
__________________________________________________________________________ 
Note (1) Measured as Rockwell superficial hardness and converted to 
Vickers hardness unless otherwise indicated with an asterisk (*). 
As many possible embodiments may be made of this invention without 
departing from the scope thereof, it being understood that all matter set 
forth is to be interpreted as illustrative and no in a limiting sense.