JPH07138601A - High cr alloy steel powder for wear resistant sintering material and its mixture - Google Patents

Abstract

PURPOSE:To provide a high Cr alloy steel powder capable of obtaining a high density and high hardness after sintering and excellent in compressibility. CONSTITUTION:This powder is a high Cr alloy steel powder of 5-30% Cr, and high compressibility is attained by controlling O, N, C, Si, Mn, and P to <=0.3%, <=0.3%, <=0.1%, <=0.1%, <=1.5%, and <=0.1% respectively. Further, graphite powder and iron-phosphorus powder are mixed and the resulting powder mixture is subjected to liquid phase sintering. By this method, the Cr alloy steel powder, useful for a sliding material for internal combustion engine, etc., can be obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high Cr alloy steel powder for wear-resistant sintered materials used as sliding materials for internal combustion engines.

[0002]

2. Description of the Related Art A sliding material such as a bubble rocker arm, a cam shaft and a tappet of an internal combustion engine is required to have wear resistance against a high surface pressure. In addition, a sintered material of high Cr alloy steel powder is used for the sliding member in order to reduce processing cost, material cost and weight reduction. This wear-resistant high-Cr alloy steel powder sintered material is sintered at the true density or near the true density by sintering using the liquid phase generation by the eutectic reaction of Fe (Cr) -C system or Fe (Cr) -PC system. To Fe (C
r) -PC It is produced by precipitating and crystallizing Cr carbide and steadite by utilizing the liquid phase generation by eutectic reaction to increase the hardness.

As raw material powder, stainless steel powder and Fe-Cr steel powder are used as a Cr source, and Fe (Cr) -C system or Fe (C
For the liquid phase generation by the r) -PC eutectic reaction, graphite powder is used as the C source and Fe-P (iron phosphorus) powder is used as the P source. In addition, P alloyed stainless steel powder or Fe-P powder mixed stainless steel powder is used as a shared source of P and Cr. Of these various powders, the main raw material powder with the largest usage ratio is stainless steel powder, P-alloyed stainless steel powder, or Fe-P powder mixed stainless steel powder, which is a water atomized steel with good cold mold forming. Use flour.

Conventionally, as stainless steel powder produced by water atomizing, Japanese Patent Publication No. 59-1761 and Japanese Patent Publication No. 62-271.
Japanese Patent No. 12 has been published as a special alloy for P-alloyed stainless steel powder.
2-13001, and Japanese Patent Laid-Open No. 1-275703 is known as Fe-P powder mixed stainless steel powder.

[0005]

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the stainless steel powder for powder metallurgy described in Japanese Patent Publication No. 59-1761, C: 0.04
%, Si: 0.5 to 1.5%, Mn: 0.4% or less, and O: 0.4% or less are disclosed. The stainless steel powder produced by water atomization is oxidized by O ₂ generated by the decomposition of water when molten steel having a stainless steel composition is sprayed with a water jet. Therefore
The Si content is higher than that of ordinary stainless steel, the surface oxidation at the time of spraying molten steel is suppressed by its oxide film action at high temperature, and the Mn content, which easily oxidizes at high temperature, is reduced to reduce the oxygen content of the powder. It is said that it should be made as low as possible for powder metallurgy.

[0006] And, the high described in Japanese Patent Publication No. 62-27112
Cr (11.0 to 31.0%) stainless steel powder is similar to the above technology in that C and N solid-solution harden residual austenite, so that C is 0.04% or less and Si is 0.5 to 1.5% or 2% or less. , Mn is 0.4% or less than 0.6%, and N is 0.03
% Of water-atomized stainless steel powder. However, even with these techniques, the steel powder after water atomization is still hard, so the compressibility is not sufficient, and it is not possible to obtain the sintered body density necessary to obtain the characteristics such as corrosion resistance as stainless steel. It was

The technique described in Japanese Patent Application Laid-Open No. 1-275703 relates to austenitic stainless steel powder, and Fe-P (
Iron Phosphorus) By mixing fine powder, it is intended to achieve high density by liquid phase sintering with a low melting point. C is 0.03% or less,
Si is limited to 1.5% or less (the lower limit is not stated), Mn is limited to 0.3% or less, and it is intended to suppress oxidation and secure compressibility during water atomization, but austenitic stainless steel powder is hard Therefore, the densification and hardening of the liquid phase sintered material could not be sufficiently achieved.

7.5 to 30.0 described in Japanese Patent Publication No. 2-13001
Steel powder (a kind of stainless steel powder) alloyed with 0.1 to 1.0% P in% Cr steel is hard and has a low green compact density in the as-water-atomized powder. There is a problem that densification and hardness are not sufficiently achieved. So this
P-containing water atomized steel powder with P of 0.1 to 1.0% and Cr of 7.0 to 30.0% is heated to a temperature of 800 ° C or more in a non-oxidizing atmosphere (H ₂ , N ₂ , Ar, vacuum vacuum, etc.). If deoxidation, decarburization, and annealing are performed to improve the compressibility, sintering with P proceeds and it becomes difficult to pulverize into powder.

Therefore, P is 0.1 to 1.0% and Cr is 7.
The water atomized steel powder containing 0 to 30.0% Cr contains C of the molten steel.
As a melting method for adjusting the amount to the 0.02% level, a method of melting scrap of low C Cr-containing stainless steel in an induction electric furnace,
If the amount is more than 0.02%, there are restrictions and problems such as the need for a molten steel treatment method that decarburizes in a vacuum or Ar atmosphere. In addition, the amount of Si in the molten steel must be 0.6% or more to suppress the oxidation during water atomization, and when solid solution hardening of Si and P and alloying carbide forming elements such as Mo, W, V, and Nb are performed. There is also a problem that the solid solution hardening of these elements further lowers the compressibility.

The present invention solves the above-mentioned problems, and C is 0.
1% or less, Si 0.1% or less, Mn 1.5% or less, Cr 5-30%,
P is 0.1% or less, O is 0.3% or less, N is 0.3% or less, and Ni, Co, Cu, Zr, Ta, Nb, V, W, and Mo are highly alloyed and highly compressible water atomized high Cr. The purpose is to provide alloy steel powder. Still further, the present invention relates to Fe when sintered.
In order to generate a liquid phase of (Cr) -C or Fe (Cr) -PC and achieve sufficient densification and high hardness, graphite powder or graphite powder
An object of the present invention is to provide a mixture of water atomized high Cr alloy steel powder for a highly compressible wear-resistant sintered material mixed with Fe-P (iron phosphorus) powder.

Furthermore, the present invention has a high compressibility in which graphite powder or graphite powder and Fe-P (iron-phosphorus) powder are mixed in which metal soap powder, camphor powder and wax are mixed so that they can be molded as they are obtained. An object of the present invention is to provide a mixture of water atomized high Cr alloy steel powders for wear-resistant sintered materials.

[0012]

According to the present invention, Cr is 5 to 30%.
In the high Cr alloy steel powder for wear-resistant sintered material, Si is 0.1% or less, Mn is 1.5% or less, P is 0.1% or less, and O 2 is annealed by annealing.
By setting 0.3% or less, N 3 to 0.3% or less, and C to 0.1% or less, sintering during annealing is prevented and the compressibility is improved.

Further, the present invention is a high Cr alloy steel powder for wear-resistant sintered material having Cr of 5 to 30%, with Si of 0.1% or less, Mn of 1.5% or less, and P of 0.1% or less such as Mn and Si. In order to reduce the easily oxidizable elements and solid solution hardening elements such as P, the reduction annealing reduced O to 0.3% or less, N to 0.3% or less, and C to 0.1% or less.
By reducing the strengthening elements such as C and N, the compressibility of high Cr alloy steel powder is improved.

Then, by mixing graphite powder or Fe-P (iron-phosphorus) powder and graphite powder with the obtained steel powder having excellent compressibility, an Fe (Cr) -C system or Fe ( A Cr) -PC eutectic liquid phase is generated to densify it, and Cr carbide is precipitated and crystallized to increase the hardness of the sintered body. Furthermore, the present invention is a high Cr alloy steel powder for wear-resistant sintered material, in which Cr is 5 to 30%, Ni, Co and Cu promote densification during liquid phase sintering, and Mn and V
, Ti, Mo, Zr, Ta and Nb are intended to further harden by precipitating and crystallizing their carbides.

Furthermore, the present invention is based on the findings described below obtained for each of a series of steps of molten steel refining-water atomizing-reduction annealing-forming-sintering. The present invention, even in high Cr molten steel, the molten steel containing 0.1% or more of C, even if the Si alloy content is 0.1% or less, Cr and other M
It is based on the knowledge that oxides of easily oxidizable elements such as n, V, Ti, Mo, Zr, Ta and Nb can be prevented from precipitating and the oxides can be water atomized without blocking the molten steel nozzle.

Further, according to the present invention, the steel powder in the state of being atomized with water is covered with an oxide film by oxidizing the molten steel with O ₂ gas generated by decomposition of water at the time of atomizing water, but the non-oxidizing atmosphere (H It is based on the knowledge that C, which is contained in molten steel in advance, can be deoxidized as CO gas by heating to a temperature of 800 ° C. or higher in ( ₂ , N ₂ , Ar, reduced pressure vacuum, etc.). Further, the present invention, Si is 0.1% or less, P is 0.1% or less, C, Si, M
n, V, Ti, Mo, Zr, Ta, Nb, and other alloyed high-Cr water-atomized steel powder in a non-oxidizing atmosphere (H ₂ , N ₂ , A
It is said that high Cr alloy steel powder with good compressibility can be produced by heating to a temperature of 800 ° C or higher (in a vacuum, vacuum, etc.) to deoxidize, decarburize, and anneal, and make C 0.1% or less. Based on knowledge.

The present invention also provides a high Cr alloy steel powder containing Si
Is less than 0.1%, P is less than 0.1%, and C is less than 0.1% by annealing.
It is based on the finding that high compressibility can be maintained even if Fe-P (iron-phosphorus) powder having a particle size of not less than 10% and graphite powder are mixed. That is, the present invention is, by weight%, C is 0.1% or less, Si is 0.1% or less, Mn is 1.5% or less, Cr is 5 to 30%, P is 0.1% or less, and O is
A high Cr alloy steel powder for wear-resistant materials, characterized in that it is 0.3% or less, N is 0.3% or less, and the balance is Fe and unavoidable impurities.The present invention is also one of Ni and Co in weight%. Or
A high Cr alloy steel powder for wear-resistant sintered material as described above, characterized in that the total of the two types contains 5% or less, and the present invention is
In addition, Cu is a high Cr alloy steel powder for wear-resistant sintered materials, characterized in that Cu contains 5% or less, and the present invention, in% by weight, Zr, Ta, Nb, Ti, V , W, Mo is a high Cr alloy steel powder for wear-resistant sintered materials, characterized in that the total of one or more of W, Mo is 10% or less. This is a mixture of high Cr alloy steel powders for wear-resistant sintered materials, characterized in that iron-phosphorus powders having a particle size of 75 μm or less and 45 μm or less and 60% or more were mixed by 0.3 to 1.5% by weight as P content. In addition, the present invention, graphite powder to any of the above steel powder
The amount of C is 1 to 3.5% by weight of 1 to 3.5% is a mixture of high Cr alloy steel powder for wear-resistant sintered material, the present invention is also one of the above steel powder metal soap powder, One or two or more of camphor powder and wax is 0% by weight.
It is a mixture of high Cr alloy steel powder for wear-resistant sintered material, characterized by being mixed in an amount of 3 to 2%.

[0018]

[Function] Next, the high Cr alloy steel powder for wear resistant sintered material of the present invention
The reason for limitation will be described. O: 0.3% or less When 0.3% is exceeded, 133 x 10^-3In a vacuum atmosphere of Pa
Fe (Cr) -C system or Fe (Cr) -P-C at temperature from 1050 to 1250 ℃
Liquid phase is difficult to wet even if liquid phase sintering is performed by eutectic reaction of the system
Hardness of the sintered material due to the generation of oxides and residual holes around them.
Is less than 0.3%. N: 0.3% or less When it exceeds 0.3%, the steel powder is solid-solution hardened and the compressibility is lowered.
Therefore, it should be 0.3% or less. C: 0.1% or less When it exceeds 0.1%, the steel powder is solid-solution hardened to reduce the compressibility.
Therefore, it should be 0.1% or less. Si: 0.1% or less If over 0.1%, the steel powder is solid-solution hardened, and the compressibility decreases.
Besides, 133 x 10 ^-3In a vacuum atmosphere of Pa, 10
Fe (Cr) -C system or Fe (Cr) -P-C system at temperatures from 50 to 1250 ℃
Acid which is hard to wet the liquid phase even if liquid phase sintering by eutectic reaction of
Compound and voids around it reduce the hardness of the sintered material.
Therefore, it should be 0.1% or less. Mn: 1.5% or less If it exceeds 1.5%, the steel powder undergoes solid solution hardening to reduce the compressibility.
Besides, 133 x 10 ^-3In a vacuum atmosphere of Pa, 10
Fe (Cr) -C system or Fe (Cr) -P at temperatures between 50 and 1250 ° C
-Liquid phase is difficult to wet even if liquid phase sintering is performed by eutectic reaction of C system
The hardness of the sintered material is low due to the residual oxides and holes around them.
Since it will be lowered, it should be 1.5% or less. P: 0.1% or less When it exceeds 0.1%, the steel powder is solid-solution hardened and the compressibility is reduced.
As a result, the residual pores in the sintered material increase and the hardness of the sintered material decreases.
Therefore, it should be 0.1% or less.

In addition, if P exceeds 0.1%, it becomes difficult to crush the cake of annealed cake of high Cr alloy steel powder for wear-resistant sintered material with 5 to 30% of Cr in the water atomized state, and it is also melt-refined. 0.1% or less is preferable because it remains in the refractory material, slag and slag of the furnace wall of the furnace, ladle and tundish and contaminates the next molten steel. Cr: at 5~30% Fe (Cr) -C system or Fe (Cr) -PC-based eutectic liquid phase sintering by reaction, by out precipitation and crystallization of Cr carbides useful H _RC as wear resistant material 50 In order to secure the above hardness, it is necessary to add 5% or more. However, if the content is too large, the compressibility decreases due to solid solution hardening and σ-phase precipitation hardening of the steel powder, and the residual pores in the sintered material increase and the hardness decreases, so the content is limited to 30% or less. The total of one or two of Ni and Co is 5% or less. Liquid phase sintering by eutectic reaction of Fe (Cr) -C system or Fe (Cr) -PC system promotes densification and sintering. Improves the solid density, but if it is too large, the steel powder will undergo solid solution hardening, which in turn reduces the compressibility,
Since the residual pores of the sintered material increase and the hardness decreases, it is set to 5% or less. Cu: 5% or less Liquid phase sintering by Fe (Cr) -C system or Fe (Cr) -PC system eutectic reaction promotes densification to improve the density of the sintered body, and fine precipitation and firing Although the hardness of the binder is improved, if it is too much, the steel powder is solid-solution hardened, rather the compressibility is lowered, the residual pores of the sintered material are increased, and the hardness is lowered. Total of 1 or 2 or more of Zr, Ta, Nb, Ti, V, W and Mo: 10% or less Liquid phase sintering by Fe (Cr) -C system or Fe (Cr) -PC system eutectic reaction However, since the carbide formation tendency is stronger than Cr, carbides of these elements are generated to further improve the hardness of the sintered material.
If it is too large, the steel powder will undergo solid solution hardening, which will rather reduce the compressibility, and the residual pores in the sintered material will increase, decreasing the hardness.
10% or less. Iron Phosphorus powder particle size: 75 μm or less and 45 μm or less 60% or more If the particle size of the iron phosphorus powder to be mixed is too coarse, the green density decreases and the liquid phase due to the eutectic reaction of the Fe (Cr) -PC system Since coarse pores remain by sintering, it is necessary to use powder of 75 μm or less and 45 μm or less of 60% or more. Addition amount of iron-phosphorus powder: 0.3 to 1.5% in P content During sintering, liquid phase sintering by eutectic reaction of Fe (Cr) -PC system promotes densification and improves density and hardness of sintered body Therefore, it is necessary to add 0.3% or more of P content. But P
If P is added excessively, the compressibility will decrease, the residual voids in the sintered material will increase, and the hardness will decrease, so the P content is limited to 1.5% or less. Graphite powder: 1-3.5% in C content Liquid phase sintering by eutectic reaction of Fe (Cr) -C system or Fe (Cr) -PC system to promote densification and improve sintered body density, And Cr
With H _RC, which is useful as a wear resistant material by precipitating and crystallizing carbide
In order to secure a hardness of 50 or more, it is necessary to add C in an amount of 1% or more. However, even if C is added excessively, the compressibility decreases, the residual pores in the sintered material increase, and the hardness decreases, so the C content is limited to 3.5% or less. Metal soap powder, camphor and wax: 1 or 2 total 0.3-1.5% graphite powder in C content 1-3.5% mixed or graphite powder in C content
1-3.5% and iron-phosphorus powder in a P content of 0.3-1.5% are mixed in 5% Cr.
High Cr steel powder for wear-resistant sintered material containing ~ 30% requires 0.3% or more of metal soap powder, camphor powder and wax to secure compressibility in mold forming. However, if the mixture is excessively mixed, the compressibility deteriorates, the residual pores in the sintered material increase, and the hardness decreases, so the content is limited to 1.5% or less.

[0020]

EXAMPLES The high Cr alloy steel powder for wear-resistant sintered material of the present invention will be described below with reference to examples. Example 1 Table 1 shows the production conditions of high Cr alloy steel powder produced by atomizing molten steel with water and performing reduction annealing in a reduced pressure vacuum. Table 2 shows the chemical composition of the produced high Cr alloy steel powder.

[0021]

[Table 1]

[0022]

[Table 2]

[0023]

[Table 3]

[0024]

[Table 4]

Using each high Cr alloy steel powder having the chemical composition shown in Table 2, 2.5% natural graphite powder by C content and 1% zinc stearate powder as a lubricant were mixed, and based on JSPM 1-64. 49
Compact density measured at 0 MPa, center C after sintering of the compact
Table 3 shows the void area ratio and hardness measured by image analysis of the directional cross section. The sintering was performed by heating to a temperature of 1230 ° C. in a vacuum of 133 × 10 ⁻³ Pa and holding for 0.5 hour.

[0026]

[Table 5]

[0027]

[Table 6]

Example 2 Using each high Cr alloy steel powder having the chemical composition shown in Table 2, 2.5% natural graphite powder in C content and 0.6% P content in particle size of 75 μm or less and 45 μm or less were 90% or less. % Fe ₃ P powder and 1% zinc stearate powder as a lubricant, and based on JSPM 1-64.
Table 4 shows the powder density measured at 490MPa, and the void area ratio and hardness measured by image analysis of the cross section in the central C direction after sintering.
Shown in. The sintering was 1150 in a vacuum of 133 × 10 ^-3 Pa.
It was heated to a temperature of ℃ and held for 0.5 hour.

[0029]

[Table 7]

[0030]

[Table 8]

As is clear from the results shown in Tables 3 and 4, the high-Cr alloy steel powder having high compressibility is Fe (Cr) -C system or Fe.
(Cr) -PC-based eutectic reaction, liquid phase sintered material has few residual pores and tends to have high hardness, but it is useful as a wear resistant material.
In order to secure hardness of 50 or more in H _RC , O of high Cr alloy steel powder is 0.3% or less, N is 0.3% or less, C is 0.1% or less, and Si is 0.
It is necessary that 1% or less, Mn is 1.5% or less, P is 0.1% or less, and Cr is 5 to 30%.

Further, the total of one or two of Ni and Co is 5% or less, Cu is 5% or less, and Zr, Ta, Nb, Ti, V, W and Mo are less than 5%.
When the total of one kind or two kinds or more is 10% or less, in the combination of these alloy compositions, those liquid phase sintered materials can secure a hardness of 50 or more in H _RC useful as a wear resistant sintered material. Example 3 O: 0.15%, N: 0, which satisfies the composition conditions of the present invention in Table 2 No. 3
04%, C: 0.01%, Si: 0.07%, Mn: 0.15%, P: 0.01%, S: 0.
Fe ₃ P with high Cr alloy steel powder with a chemical composition of 01% and Cr: 8.5%
P content of powder, particle size of Fe ₃ P powder, C content of natural graphite powder, zinc stearate (ZnSt) powder as lubricant, camphor and wax, and mixed according to JSPM 1-64. Dust density measured at 490 MPa and center C after sintering
Table 5 shows the void area ratio and hardness measured by image analysis of the cross section. The sintering was performed by heating to a temperature of 1150 ° C. in a vacuum of 133 × 10 ⁻³ Pa and holding for 0.5 hour.

[0033]

[Table 9]

[0034]

[Table 10]

As is clear from the results shown in Table 5, Fe ₃ P powder having a particle size of 75% or less and 45% or less 90% is 90% by P content.
When mixed with 1.5%, and in Fe ₃ P powder at 75 μm or less
When 45 μm or less is mixed with a particle size of 60% or more, and when graphite powder is mixed in a C content of 1 to 3.5%, and as a lubricant, one or two of zinc stearate powder, camphor powder and wax is mixed. When a total of 0.3 to 2% is mixed, for each of the high Cr alloy steel powders, the Fe (Cr) -PC liquid phase sintered material is 50 or more in H _RC which is useful as an abrasion resistant sintering agent. The hardness of can be secured.

Example 4 The high Cr alloy steel powder of the present invention having the chemical composition shown in Table 6 was used in Example 1
The Fe ₃ P powder, the graphite powder and the lubricant (zinc stearate powder, camphor powder and wax for the present weight ratio) were mixed under the conditions of the present invention.

[0037]

[Table 11]

Table 7 shows the green compact density measured at 490 MPa based on JSPM 1-64, and the void area ratio and hardness measured by image analysis of the cross section in the central C direction after sintering.

[0039]

[Table 12]

Sintering was carried out in a vacuum of 133 × 10 ^-3 Pa under reduced pressure.
It was heated to a temperature of 1150 ° C and kept for 0.5 hour. As is clear from the results in Table 7, all of the high Cr alloy steel powders of the present invention have good compressibility, and the Fe (Cr) -PC system liquid phase sintered material is excellent as an abrasion resistant sintering agent. _RC shows hardness of 50 or more.

[0041]

INDUSTRIAL APPLICABILITY The present invention provides water atomized Cr in an amount of 5 to 30.
Cr alloy steel powder containing 50% is annealed, O is 0.30% or less, N is 0.3%
Below, C is 0.1% or less, Si is 0.1% or less, Mn is 1.5% or less, P
Is less than 0.1%, it is highly compressible, and Ni, Co and Cu
In addition to being able to alloy a high content of the sinter-promoting element, the alloying elements of Zr, Ta, Nb, Ti, V, W and Mo can be alloyed in a high content.

Further, since the high Cr alloy steel powder of the present invention has good compressibility, iron-phosphorus (Fe-P) powder having a coarse grain size is used, and remains even when mixed with graphite powder and liquid phase sintered. A high-hardness wear-resistant sintered material with few pores can be manufactured. Further, since the high Cr alloy steel powder of the present invention contains iron-phosphorus (Fe-P) powder, graphite powder and lubricant powder, it can be immediately molded as it is obtained.

Claims (7)

[Claims] 1. By weight%, C is 0.1% or less, Si is 0.1% or less, Mn is 1.5% or less, Cr is 5 to 30%, P is 0.1% or less, and O is
High Cr alloy steel powder for wear-resistant sintered materials, characterized in that it is 0.3% or less, N 3 is 0.3% or less, and the balance is Fe and inevitable impurities. 2. The high Cr alloy steel powder for wear-resistant sintered material according to claim 1, characterized in that the total content of one or two of Ni and Co is 5% or less by weight. 3. The high Cr alloy steel powder for wear-resistant sintered material according to claim 1, wherein the content of Cu is 5% or less by weight. 4. Zr, Ta, Nb, Ti, V, W, Mo in wt%
4. The high Cr alloy steel powder for wear-resistant sintered material according to claim 1, wherein the total of one kind or two kinds or more of 10% or less is contained. 5. The iron powder having a particle size of 75 μm or less and 45 μm or less and 60% or more in the steel powder according to any one of claims 1, 2, 3, and 4 is 0.3% by weight as a P content. A mixture of high Cr alloy steel powder for wear-resistant sintered materials, characterized by being mixed at 1.5%. 6. The steel powder according to any one of claims 1, 2, 3 and 4 or the mixture according to claim 5, wherein 1 to 3.5% by weight of graphite powder as a C content is mixed. A mixture of high Cr alloy steel powder for wear-resistant sintered materials. 7. The steel powder according to claim 1, 2, 3, or 4 or the mixture according to claim 5 or 6, and a total of one or more of metal soap powder, camphor powder and wax. Is a mixture of high Cr alloy steel powder for wear-resistant sintered materials, characterized by being mixed by 0.3 to 2% by weight.