Properties of High Density Sinter-Hardening P/M Steels
Processed Using an Advanced Binder System
Michael L. Marucci, Michael C. Baran, and K.S. Narasimhan
Hoeganaes Corporation
Cinnaminson, NJ 08077
Presented at PM2TEC2002
World Congress on Powder Metallurgy & Particulate Materials
June 16-21, 2002, Orlando, Florida
ABSTRACT
Sinter-hardening P/M alloys offer an excellent opportunity for a part manufacturer to produce
hardened components in an economical fashion by eliminating secondary heat-treatments.
Unfortunately, sinter-hardening P/M base iron grades are prealloyed with substantial levels of
Ni, Mn, and Mo which increase hardenability but reduce compressibility. Furthermore, Cu and
graphite are added to further increase strength and hardness. These alloying additions all
reduce compressibility limiting the maximum attainable green and sintered densities. This
paper explores how processing sinter-hardening alloys with a new proprietary binder system
can improve compressibility and lead to higher densities and mechanical properties. The data
show green density increases of 0.05-0.15 g/cm3 and be achieved and can result in tensile
strength and hardness improvements.
BACKGROUND
Increasingly, powder metallurgy parts producers have improved the performance of their
products by using sinter-hardening steel alloys. The ability to harden a part directly from
sintering temperature without the use of a secondary heat-treatment is very attractive as it
reduces cost. Unfortunately, most sinter-hardening alloys are prealloyed with nickel, a ferrite
hardener, that can reduce compressibility resulting in a compact with a reduced density. In
addition, these prealloys are often admixed with copper to further increase hardenability. When
sintered at conventional temperatures [1120 °C (2050 °F)] copper often causes growth resulting
in a sintered density which is lower than the green density.
There are several approaches to increase the final sintered density including double pressdouble sinter, high temperature sintering, and/or the use of lubricant/binder systems. The use
of specialized lubricant/binder systems is especially attractive because it does not involve the
use of additional process steps and, depending on the alloy system, can be sintered at
conventional temperatures.
This paper presents the mechanical properties of sinter-hardening alloys that have been
processed using ANCORMAX DTM, a recently developed proprietary lubricant/binder system.
This process is an improvement over previous systems because it provides a significant
increase in green density without requiring powder heating. However, to realize the full green
density increase, the die temperature must be in the range of 60 to 70 °C (140 to 160 °F).
INTRODUCTION
Density
It is widely accepted that increasing the density improves the mechanical properties of a
sintered part. In a sinter-hardening material the sintered microstructure consist of more than
90% martensite. This very hard structure improves the ultimate strength and apparent
hardness, however, as the hardness increase the material becomes more notch sensitive.
Therefore, higher densities are necessary to further increase the strength of the steel because
the reduced number/size of pores lowers the maximum defect size in the material.
When attempting to attain high densities the concept of pore free density must be considered.
Pore free density is the density of a green compact where all porosity between particles has
been eliminated. This value can be calculated by taking the weighted average of the specific
density of each addition in the premix. Therefore, light additions such as graphite or lubricant
will reduce the pore free density of a iron/graphite compact. In uniaxial compaction, there is a
practical upper limit of pore free density that can be attained due to material plasticity limitations.
This limit falls around 98.5%1. If a material is compacted beyond 98.5% of its pore free density,
it tends to develop cracks or laminations and its mechanical performance is reduced.
The newly developed lubricant/binder system enables the compaction of sinter-hardening P/M
steels to densities in the range of 95-97% of pore free density. The intrinsically less
compressible sinter-hardening base iron alloys reduce the chance of exceeding 98.5% of pore
free density. However, this concept is important when compacting any alloy because the
experimenter should know the maximum attainable green density.
Lubricant/Binder System
The use of advanced lubricant/binder systems yields many advantages over more traditional
admixed lubricant additions2. Advantages include reduced alloy segregation, reduced dusting,
and better alloy homogeneity. Bonding also produces better flow and die fill that results in
improved weight control and dimensional tolerance. In addition, advancements in the bonding
technology has resulted in improved compressibility and reduced ejection forces.
Established technologies such as ANCORDENSE processing require that the die and powder
be heated to 120-150 °C (250-300 °F) in order to attain improvements in density. The heating is
necessitated by the thermal properties of the organic binder. Continued research efforts have
yielded improvements in binder technology that will, for certain part geometries, increase the
green density by 0.05-0.15 g/cm3. The resulting system has been designed so that only the die
need to be heated in the range of 60-70 °C (140-160 °F). The powder can be left at ambient
temperature until it flows into the die.
The advantages of this system include the
aforementioned density gain of 0.05-0.15 g/cm3, less compulsory equipment such as powder
heaters, and less powder waste. Some limitations include a maximum part height of 19-25.4
mm (0.75-1.00 in.) due to limited heat transfer in the die and the continued need for a heated
die.
Alloy Composition
The alloying additions, both prealloyed and admixed, affect the final properties of the sintered
part. The hardenability of the alloy plays a large part in determining the final mechanical
properties of a given alloy. In general, more hardenable materials (steels that form martensite
at lower cooling rates) have higher strength, hardness, and impact properties. Unfortunately,
alloy additions alone are not the only determiner of final properties. The cooling rate from
sintering temperature has a large effect on the properties of any sinter-hardening P/M steel.
The alloy must be tailored for the intended cooling rate to ensure the desired final microstructure
contains beneficial constituents such as martensite, bainite, or fine pearlite that aid properties.
Highly hardenable steels which contain high levels of Cu, Mn, Mo, and Ni in combination with a
carbon level >0.75 w/o C tend to form retained austenite at moderate cooling rates (convection
cooling like rates)3. In addition, it has been shown that sinter-hardening steels containing 2.0
w/o Cu and greater than 0.75 w/o C form retained austenite at particle boundaries where
admixed Cu has diffused, when an accelerated cooling profile is used4. These materials should
be used with a slower conventional cooling rate, which is slow enough to allow retained
austenite to form intermediate phases such as ferrite and carbide. Accelerated sintering
furnace cooling should be used in conjunction with moderately alloyed steels containing less
carbon and Cu. The fast cooling rate will allow for the formation of martensite and be less likely
to form retained austenite.
EXPERIMENTAL PROCEDURE
Alloys
The compositions tested in this study are listed in Table I. All materials were prepared using the
proprietary ANCORMAX D system (Except Material #3 which is a premix containing 0.75 w/o
Lonza Acrawax C as a reference.). 225 kg (500 lb.) mixes were prepared for each alloy. The
elemental copper used was ACuPowder 8081, the elemental nickel used was INCO Type 123,
and the graphite used was Asbury 3203.
Table I: Sinter-Hardening Alloy Matrix
Prealloyed
Material
Base Iron
1
2
3 (Ref.)
4
Ancorsteel 737SH
Ancorsteel 737SH
Ancorsteel 737SH
Ancorsteel 4600V
Mo
( w/o
)
1.25
1.25
1.25
0.56
Admixed
Ni
( w/o )
Mn
( w/o )
Cu
( w/o )
Gr
( w/o )
Organic
( w/o )
1.40
1.40
1.40
1.83
0.42
0.42
0.42
0.15
2.0
1.0
2.0
2.0
0.9
0.7
0.9
0.9
0.55
0.55
0.75 (Acrawax C)
0.55
Compaction
The mechanical test samples were uniaxially compacted in a rigid die at 550, 690, and 830 MPa
(40, 50, and 60 tsi). All samples were compacted with a die preheated to 63 °C (145 °F).
Sintering
All test pieces were sintered in a continuous Abbott furnace equipped with a high temperature
ceramic belt and a convection cooling section. Several sintering conditions were used to mimic
different production sintering cycles and are outlined in Table II. All samples were at sintering
temperature for 30 minutes. The standard and accelerated cooling rates are 16 °C/min (30
°F/min) and 47 °C/min (85 °F/min), respectively, from 700 °C (1300 °F) to 150° C (300 °F).
Table II: Sintering Conditions for Sinter-Hardening Alloys
Material
1
2
3 (Ref.)
4
Sintering Temperatures
°C (°F)
1120 (2050)
1120 (2050)
1120 (2050)
1120 (2050)
Sintering Atmospheres
(v/o)
90N2/10H2 & 25N2/75H2
90N2/10H2 & 25N2/75H2
90N2/10H2 & 25N2/75H2
90N2/10H2 & 25N2/75H2
Cooling
Standard & Accelerated
Standard & Accelerated
Standard & Accelerated
Standard & Accelerated
Mechanical Testing
Tensile tests were performed using dog-bone samples tested according to ASTM Standard E85
and MPIF Standard 106, transverse rupture (TRS) tests were performed using MPIF Standard
41, unnotched Charpy impact tests were conducted according to MPIF Standard 40, and
rotating bending fatigue (RBF) testing was done according to MPIF Standard 56. Five
specimens were made and tested for each condition. The properties obtained from the
mechanical test samples include: green and sintered density, dimensional change, transverse
rupture, yield strength, tensile strength, elongation, impact energy and apparent hardness.
RESULTS AND DISCUSSION
The mechanical property data for the sinter-hardening alloys is shown in Appendix A. The data
show some interesting trends which will be discussed in the proceeding paragraphs.
Density
The green density attained by using the advanced lubricant/binder system on these alloys was
an improvement over conventional lubricant additions. This system produced a green density
increase of 0.10 g/cm3. This density gained is especially beneficial to sinter-hardening alloy
system because the base iron powders were prealloyed with Ni, Mo, and Mn, all alloys that
reduced compressibility. Figure 1 shows the compressibility curve for these sinter-hardening
alloys. The chart shows that density continues to increase beyond 690 MPa (50 tsi) up to 830
MPa (60 tsi). For Material 1, the green density had reached 7.27 g/cm3, which is 97% of the
alloy's pore free density. In addition, Material 2 displayed a slightly higher compressibility
throughout the range tested. The density of these alloys sintered at 1120°C (2050°F) is shown
in Figure 2. The copper caused a net volume gain in the sample upon sintering, reducing the
density. However, the higher green density of the ANCORMAX D processed alloys carried over
through sintering resulting in a finished part density that was greater than a part produced using
a traditional system.
7.40
7.30
GD (g/cm3)
7.20
7.10
7.00
Material 1
Material 2
6.90
Material 3 (Ref.)
Material 4
6.80
35
(480)
40
(550)
45
(620)
50
(690)
55
(760)
60
(830)
65
(900)
Compaction Pressure, tsi (MPa)
Figure 1: Compressibility Curve for Sinter-Hardening Alloys
7.40
7.30
SD (g/cm3)
7.20
7.10
7.00
Material 1
Material 2
6.90
Material 3 (Ref.)
Material 4
6.80
35
(480)
40
(550)
45
(620)
50
(690)
55
(760)
60
(830)
65
(900)
Compaction Pressure, tsi (MPa)
Figure 2: Sintered Density of Sinter-Hardening Alloys
(Sintered at 1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, Tempered at 200 °C (400 °F) for 1 h)
Strength
The strength advantage due to the density gain was apparent when comparing the tensile
strengths of the different alloys. Comparing the tensile data for Material 1 with the data for
Material 3 (Figure 3) revealed that the tensile strength increased by 10% throughout the entire
range using the standard cooling profile. Accelerated cooling showed similar results at the
higher compaction pressure but less of a change at 550 MPa (40 tsi).
Another advantage of the density gain was seen by comparing the tensile data for the Material 2
with the Material 3 data in Figure 5. The density increase has improved the strength of the
leaner alloy to the same level as the more highly alloyed mix. This observation was notable
because with the higher density a leaner alloy addition may be substituted, leading to a more
economical premix.
(1100) 160
TS, 103 psi (MPa)
(1035) 150
(965) 140
(900) 130
(830) 120
Material 1
Material 2
(760) 110
Material 3 (Ref.)
Material 4
(690) 100
35
(480)
40
(550)
45
(620)
50
(690)
55
(760)
60
(830)
65
(900)
Compaction Pressure, tsi (MPa)
Figure 3: Tensile Strength of Sinter-Hardening Alloys
(Sintered at 1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, Standard Cooling, Tempered at 200 °C (400 °F) for 1 h)
(1100)160
TS, 103 psi (MPa)
(1035)150
(965) 140
(900) 130
(830) 120
Material 1
Material 2
(760) 110
Material 3 (Ref.)
Material 4
(690) 100
35
(480)
40
(550)
45
(620)
50
(690)
55
(760)
60
(830)
65
(900)
Compaction Pressure, tsi (MPa)
Figure 4: Tensile Strength of Sinter-Hardening Alloys
(Sintered at 1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, Accelerated Cooling, Tempered at 200 °C (400 °F) for 1 h)
(1100) 160
(965) 140
(900) 130
3
TS, 10 psi (MPa)
(1035) 150
(830) 120
Material 1
(760) 110
Material 2
Material 3 (Ref.)
(690) 100
6.90
6.95
7.00
7.05
7.10
7.15
7.20
7.25
7.30
Sintered Density, g/cm3
Figure 5: Tensile Strength of Sinter-Hardening Alloys
(Sintered at 1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, Standard Cooling, Tempered at 200 °C (400 °F) for 1 h)
Hardness
The hardness data for these alloys is shown in Figures 6 and 7. The hardness scaled with
density. Again an increase in apparent hardness in higher density materials was observed
compared with the standard premix. This increase was valuable as it can enhance wear
resistance.
50
Hardness, HRC
45
40
35
Material 1
30
Material 2
Material 3 (Ref.)
25
Material 4
20
35
(480)
40
(550)
45
(620)
50
(690)
55
(760)
60
(830)
65
(900)
Compaction Pressure, tsi (MPa)
Figure 6: Apparent Hardness of Sinter-Hardening Alloys
(Sintered at 1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, Standard Cooling, Tempered at 200 °C (400 °F) for 1 h)
The apparent hardness of materials containing 2.0 w/o Cu and 0.9 w/o Gr was not substantially
changed by the accelerated cooling rate. However, the 1.0 w/o Cu + 0.7 w/o Gr samples
displayed a substantial increase in hardness when the accelerated cooling rate was used. This
was a clear example of how an accelerated cooling rate can be used in conjunction with high
densities to improve mechanical properties without increasing alloy content.
50
45
Hardness, HRC
40
35
30
Material 1
Material 2
Material 3 (Ref.)
25
Material 4
20
35
(480)
40
(550)
45
(620)
50
(690)
55
(760)
60
(830)
65
(900)
Compaction Pressure, tsi (MPa)
Figure 7: Apparent Hardness of Sinter-Hardening Alloys
(Sintered at 1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, Accelerated Cooling, Tempered at 200 °C (400 °F) for 1 h)
The higher density materials resulted in only a modest increases in elongation and impact
energy. The toughness of the material stayed relatively constant across the density range and
was unaffected by what system was used. Also, there was no appreciable difference between
tensile strength and yield strength. All of these properties are related to the highly martensitic
microstructure, and it has been shown that the elongation, impact energy plateau at graphite
levels above 0.7 w/o and Cu levels above 1.0 w/o in Ancorsteel 737SH7.
Fatigue
Rotating bending fatigue (RBF) tests show that the survival limit increases when the sintered
density is increased by 0.10 g/cm3 for materials mixed with 0.9 w/o Graphite and 2.0 w/o Cu.
Table III shows the RBF results for Materials 1 and 3. A 14% increase in the 50 and 90%
survival limits was observed for Material 1, which has a higher density.
Table III: RBF Data for Sinter-Hardening Alloys
Material
1
3 (Ref.)
Pressure
Pressure
(tsi)
(MPa)
50
50
690
690
Sintered
D ensity
(g/cm 3)
7.14
7.05
90% Survival 90% Survival 50% Survival 50% Survival
Limit
Limit
Limit
Limit
(tsi)
(MPa)
(tsi)
(MPa)
44.4
38.3
306
264
45.8
39.4
316
272
TS
TS
(tsi)
143
130
(MPa)
986
894
Microstructure
Examination of Figure 8 shows that the sample that underwent standard cooling consists of
coarse lath martensite and areas of bainite the accelerated cooling sample has finer martensite
and fine areas of retained austenite. The presence of bainite in the standard cooled sample
toughens the steel producing better properties than the accelerated cooling sample with the
retained austenite. Reducing the admixed copper will produce the desirable fine martensitic
structure with reduced quantities of retained austenite. Figure 9 shows this clearly. The
standard cooling sample consist of coarse lath martensite, divorced pearlite, and bainite. The
accelerated cooling sample consists of fine martensite with a trace amount of bainite. In this
instance the retained austenite is not present in the final microstructure leading to a steel with
excellent properties.
a.
b.
40 µm
40 µm
Figure 8: Microstructure of Material 1 sintered at
1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, a.) standard cooling, b.) accelerated cooling, optical
micrograph (2% Nital/4% Picral Etch)
b.
a.
40 µm
40 µm
Figure 9: Microstructure of Material 2 sintered at
1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, a.) standard cooling, b.) accelerated cooling, optical
micrograph (2% Nital/4% Picral Etch)
CONCLUSIONS
•
•
•
•
ANCORMAX D processing can increase the green and sintered density of common sinterhardening alloys by 0.05-0.15 g/cm3.
A 10% increase in tensile strength was observed when the density was increased by about
0.10 g/cm3.
Apparent hardness increased as the density increased in sinter-hardening alloys.
A 14% increase in RBF survival limits was observed when the sintered density was
increased by 0.10 g/cm3.
FUTURE WORK
The next step in this work would be to combine the ANCORMAX D system with different Cu and
graphite additions to identify the best composition. This work will be done in conjunction with a
specific cooling rate to attain greater impact energies and more ductility in a sinter-hardening
material.
ACKNOWLEGEMENTS
The authors would like to extend their appreciation to George Fillari and Dave Southwick for
their significant work on mechanical testing for this work. In addition, Gerry Golin and Steve
Kolwicz have to be recognized for their work on preparing the microstructures reproduced
above.
REFERENCES
1
Hanejko, F.G., "Warm Compaction", ASM Handbook, Vol. 7, pp. 327-328, ASM International, Materials
Park, OH, 1998.
2
Semel, F.J. and McDermott, M.J., "Recent Applications of Binder Treatment Technology", Advances in
Powder Metallurgy & Particulate Materials, Vol. 1, pp. 2-23 - 2-49, Metal Powder Industries Federation,
Princeton, NJ, 1997.
3
Roberts, G.A. and Cary, R.A., Tool Steels, 4th Ed. American Society for Materials, Metals Park, OH,
1980, pp. 213-217.
4
Baran, M.C., and Murphy, T.F., "Metallographic Testing to Determine the Influence of Carbon and
Copper on the Retained Austenite Content in a Sinter-Hardening Material", P/M Science & Technology
Briefs, Vol. 1, No. 3, 1999 pp. 22-26.
5
ASTM Standard E8, "Standard Test Methods for Tension Testing of Metallic Materials", Annual Book of
ASTM Standards, Vol. 3.01, pp. 57-72, American Society for Testing and Materials, West
Conshohocken, PA, 2000.
6
Standard Test Methods for Metal Powders and Powder Metallurgy Products, Metal Powder Industries
Federation, Princeton, NJ, 2002.
Appendix A: Mechanical Properties of Sinter-Hardening Alloys
Green Properties
Sintered Properties of Sinter-Hardening Alloys, Standard Cooling
Sintered at 1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, Tempered at 200 °C (400 °F) for 1 h
Pressure
Pressure
(tsi)
(MPa)
Sintered
Density
(g/cm³)
Dimensional
Hardness
Change
(%)
(HRC)
ANCORMAX D 737SH + 2.0 w/o Cu + 0.9 w/o Gr
40
550
6.97
0.27
50
690
7.14
0.32
60
830
7.24
0.36
ANCORMAX D 737SH + 1.0 w/o Cu + 0.7 w/o Gr
40
550
7.01
0.23
50
690
7.11
0.27
60
830
7.25
0.32
TRS
YS
YS
TS
TS
Elong.
(10 psi)
TRS
(MPa)
(10 psi)
(MPa)
(10 psi)
(MPa)
(%)
(ft.lbf)
(J)
36
40
42
230
266
278
1586
1834
1917
126
137
143
871
946
986
130
143
151
894
986
1044
0.9
0.9
0.9
11
12
15
17
28
27
36
217
242
274
1497
1669
1890
111
127
134
764
879
923
117
130
135
804
896
929
0.7
0.8
0.8
10
10
13
14
35
37
39
238
266
271
1641
1834
1869
109
121
128
749
838
883
117
130
135
808
894
931
0.9
0.9
0.9
13
12
18
17
32
36
39
220
247
271
1517
1703
1869
NY
NY
NY
NY
NY
NY
111
128
128
769
883
886
0.7
0.8
0.8
11
13
14
18
3
3
3
Impact Impact
Ancorsteel 737SH + 2.0 w/o Cu + 0.9 w/o Gr + 0.75 w/o Acrawax C
40
550
6.92
0.14
50
690
7.05
0.17
60
830
7.12
0.22
ANCORMAX D 4600V + 2.0 w/o Cu + 0.9 w/o Gr
40
550
6.93
0.42
50
690
7.11
0.47
60
830
7.20
0.51
Sintered Properties of Sinter-Hardening Alloys, Accelerated Cooling
Sintered at 1120 °C (2050 °F) in 90 v/o N2/10 v/o H2, Tempered at 200 °C (400 °F) for 1 h
Pressure
Pressure
(tsi)
(MPa)
Sintered
Density
(g/cm³)
Dimensional
Hardness
Change
(%)
(HRC)
ANCORMAX D 737SH + 2.0 w/o Cu + 0.9 w/o Gr
40
550
6.95
0.27
50
690
7.14
0.30
60
830
7.23
0.35
ANCORMAX D 737SH + 1.0 w/o Cu + 0.7 w/o Gr
40
550
6.98
0.24
50
690
7.15
0.30
60
830
7.25
0.36
TRS
YS
YS
TS
TS
Elong.
(10 psi)
TRS
(MPa)
(10 psi)
(MPa)
(10 psi)
(MPa)
(%)
(ft.lbf)
(J)
37
42
43
234
261
282
1614
1800
1945
NY
NY
NY
NY
NY
NY
122
140
145
842
965
1002
0.8
0.8
0.8
11
13
14
17
34
38
42
243
269
276
1676
1855
1903
NY
108
NY
NY
747
NY
114
128
132
789
880
909
0.7
0.7
0.6
9
10
12
14
35
39
42
232
260
278
1600
1793
1917
NY
NY
129
NY
NY
890
120
127
133
828
876
916
0.8
0.8
0.8
11
12
15
17
36
40
43
204
229
255
1407
1579
1759
NY
NY
NY
NY
NY
NY
113
123
130
776
848
893
0.7
0.7
0.7
10
11
13
15
3
3
3
Impact Impact
Ancorsteel 737SH + 2.0 w/o Cu + 0.9 w/o Gr + 0.75 w/o Acrawax C
40
550
6.90
0.13
50
690
7.05
0.17
60
830
7.13
0.19
ANCORMAX D 4600V + 2.0 w/o Cu + 0.9 w/o Gr
40
550
6.93
0.41
50
690
7.11
0.46
60
830
7.22
0.50
Sintered Properties of Sinter-Hardening Alloys, Standard Cooling
Sintered at 1120 °C (2050 °F) in 75 v/o H2/25 v/o N2, Tempered at 200 °C (400 °F) for 1 h
Pressure
Pressure
(tsi)
(MPa)
Sintered
Density
(g/cm³)
Dimensional
Hardness
Change
(%)
(HRC)
ANCORMAX D 737SH + 2.0 w/o Cu + 0.9 w/o Gr
40
550
6.98
0.23
50
690
7.14
0.27
60
830
7.23
0.34
ANCORMAX D 737SH + 1.0 w/o Cu + 0.7 w/o Gr
40
550
6.96
0.26
50
690
7.15
0.28
60
830
7.24
0.32
TRS
YS
YS
TS
TS
Elong.
(10 psi)
TRS
(MPa)
(10 psi)
(MPa)
(10 psi)
(MPa)
(%)
(ft.lbf)
(J)
36
42
44
219
248
253
1510
1710
1745
NY
NY
NY
NY
NY
NY
121
129
137
837
891
945
0.7
0.7
0.7
11
12
15
16
28
35
36
256
286
298
1766
1972
2055
NY
147
NY
NY
1016
NY
120
152
160
830
1046
1104
0.6
0.8
0.9
12
0
84
35
38
41
220
220
241
1517
1517
1662
NY
125
132
NY
863
908
119
136
138
822
935
948
0.7
0.9
0.9
13
12
18
17
34
40
41
207
212
229
1428
1462
1579
NY
NY
141
NY
NY
974
122
133
144
843
918
994
0.8
0.7
0.8
13
15
17
20
3
3
3
Impact Impact
Ancorsteel 737SH + 2.0 w/o Cu + 0.9 w/o Gr + 0.75 w/o Acrawax C
40
550
6.90
0.14
50
690
7.04
0.19
60
830
7.11
0.24
ANCORMAX D 4600V + 2.0 w/o Cu + 0.9 w/o Gr
40
550
6.93
0.34
50
690
7.10
0.47
60
830
7.19
0.52
Sintered Properties of Sinter-Hardening Alloys, Accelerated Cooling
Sintered at 1120 °C (2050 °F) in 75 v/o H2/25 v/o N2, Tempered at 200 °C (400 °F) for 1 h
Pressure
Pressure
(tsi)
(MPa)
Sintered
Density
(g/cm³)
Dimensional
Hardness
Change
(%)
(HRC)
ANCORMAX D 737SH + 2.0 w/o Cu + 0.9 w/o Gr
40
550
6.98
0.23
50
690
7.15
0.29
60
830
7.23
0.37
ANCORMAX D 737SH + 1.0 w/o Cu + 0.7 w/o Gr
40
550
6.96
0.25
50
690
7.15
0.30
60
830
7.25
0.35
TRS
YS
YS
TS
TS
Elong.
(10 psi)
TRS
(MPa)
(10 psi)
(MPa)
(10 psi)
(MPa)
(%)
(ft.lbf)
(J)
37
42
44
227
239
254
1566
1648
1752
NY
NY
NY
NY
NY
NY
118
124
129
814
855
889
0.7
0.6
0.6
11
12
15
17
32
39
41
228
265
281
1572
1828
1938
NY
NY
NY
NY
NY
NY
122
159
157
840
1094
1084
0.7
0.8
0.8
10
11
14
15
36
39
41
214
243
239
1476
1676
1648
121
NY
NY
834
NY
NY
127
130
139
876
896
958
0.9
0.8
0.8
11
12
15
17
35
41
42
215
217
230
1483
1497
1586
NY
NY
NY
NY
NY
NY
117
141
137
810
974
948
0.7
0.8
0.8
11
13
15
18
3
3
3
Impact Impact
Ancorsteel 737SH + 2.0 w/o Cu + 0.9 w/o Gr + 0.75 w/o Acrawax C
40
550
6.89
0.16
50
690
7.04
0.22
60
830
7.11
0.25
ANCORMAX D 4600V + 2.0 w/o Cu + 0.9 w/o Gr
40
550
6.92
0.40
50
690
7.10
0.46
60
830
7.18
0.50