WO2005037469A1

WO2005037469A1 - Wear-resistant parts and method for manufacture thereof

Info

Publication number: WO2005037469A1
Application number: PCT/JP2004/015429
Authority: WO
Inventors: Hiroyuki Fukuhara; Kenji Sasaki; Kensuke Hirata; Toshihiko Homma
Original assignee: Matsushita Electric Industrial Co., Ltd.; Kawasaki Nitriding Co., Ltd.
Priority date: 2003-10-21
Filing date: 2004-10-19
Publication date: 2005-04-28
Also published as: US20080216923A1; US20070071630A1; KR20060126962A; JPWO2005037469A1; CN1871084A; JP4668793B2

Abstract

A method for manufacturing wear-resistant parts which comprises the steps of molding a material from a powder of an iron-based alloy containing Cr by the compressed powder sintering molding, and subjecting the material to a nitriding treatment precluding a carburized component, to thereby form a surface having a mixed structure (3) comprising a compound layer (2) of Fe-Cr-N, a diffusion layer of Fe-Cr-N and a base material

Description

Specification

Wear-resistant parts and method of manufacturing the same

Technical field

The present invention relates to a wear-resistant part whose hardness has been increased by nitriding and a method for producing the same.

Background art

[0002] A vane provided in a rotary compressor or the like is slidably mounted in a vane groove formed in a cylinder. The vane has a side surface in sliding contact with a side wall of the vane groove and a tip end portion thereof. Abrasion resistance is required because of sliding contact with the roller. Therefore, chromium-containing steel, sintered alloy, or ferrous iron is used as the base material, and the base material is subjected to soft nitriding to form the first compound layer of FeCrN on the surface layer, A structure in which a second compound layer made of the same component is formed below one compound layer has been proposed (for example, see Patent Document 1).

[0003] There is also proposed to be the formation of the nitrided layer by performing a nitriding treatment on the surface of the base material of stainless steel (e.g., see Patent Document 2.) ₀

[0004] Furthermore, after sintering iron having a porosity of 10% or less or 15% or less using a material of an iron-based powder material to form a martensite structure in the matrix by quenching and tempering, the surface is nitrided or hardened In some of them, a compound layer having an Fe—N force is formed by nitrocarburizing treatment, and a nitrogen diffusion layer is formed inside the compound layer (for example, see Patent Documents 3 and 4;).

Patent Document 1: JP-A-60-26195

Patent Document 2: JP-A-11-101189

Patent Document 3: JP 2001-140782A

Patent Document 4: JP 2001-342981 A

Disclosure of the invention

Problems to be solved by the invention

However, in the above-described conventional configuration, the surface is formed of FeCrN or a compound layer of FeN or a diffusion layer of FeCrN, and the surface has a single composition and uniform hardness. As a result, the wear of wear-resistant parts such as vanes generated when the compressor was operated was uniform. As a result, there is a possibility that seizure, which makes it difficult to maintain a predetermined oil retaining property on the surface, may occur.

[0007] The present invention has been made in view of such problems of the prior art, and forms a minute oil reservoir by forming a surface of a wear-resistant part with a mixed surface having different hardness. An object of the present invention is to provide a highly wear-resistant part that can improve oil retention when the wear-resistant part is operated and that can eliminate defects such as image sticking. Means for solving the problem

[0008] In order to achieve the above object, a method of manufacturing a wear-resistant part that is effective in the present invention is to form a material by compacting and sintering using an iron-based alloy powder containing Cr to reduce a carburizing component. It is characterized by the fact that the surface is treated as a mixed structure of Fe-Cr-N compound layer, Fe-Cr-N diffusion layer and matrix by excluding nitriding treatment.

[0009] Another embodiment of the method of manufacturing a wear-resistant part according to the present invention is to use an alloy powder containing at least one metal element of Mn, Ti, and V as an iron-based alloy powder containing Cr. Then, the material was formed by green compact sintering, nitriding treatment was performed to eliminate the carburizing component, and the surface was made to have a mixed structure of Fe-CrN compound layer, Fe-CrN diffusion layer and matrix. Features.

[0010] Preferably, there is a vacancy on the surface, a Fe-CrN compound layer in the vicinity of the vacancy, and a mixed structure of a Fe-CrN diffusion layer and a matrix as the distance from the vacancy increases. Is good.

[0011] Still another embodiment of the method of manufacturing a wear-resistant part according to the present invention is a method of forming a material by compacting and sintering using an iron-based alloy powder containing Cr and removing a carburized component. The surface is treated as a mixed structure of a Fe-CrN compound layer, a Fe-Cr to N diffusion layer, and a sorbite matrix structure.

In this case, vacancies exist on the surface, and the vicinity of the vacancies is separated from the vacancies by a Fe—CrN compound layer! ヽ The diffusion layer of Fe—CrN and the base of the sorbite structure It is better to have a mixed structure with.

[0013] In addition, after the material is formed by green compact sintering, quenched, and tempered, a nitriding treatment that excludes a carburizing component is performed, a part of the surface is removed, and at least the surface is made of Fe— Cr N A mixed structure including a compound layer can also be used.

[0014] Air treatment for slight acid treatment before nitriding may be performed, but the air treatment is preferably performed at a temperature of 380 ° C or higher.

[0015] The wear-resistant part has a compound layer of Fe-Cr to N, a diffusion layer of Fe-CrN, and a mixed structure of matrix on the surface, and almost the entire surface of the sintered material after nitriding is 0.1%. 1-0.5 It is covered with particles or protrusions of about 5 m.

The invention's effect

[0016] The present invention is configured as described above, and has the following effects.

Using a powder compact sintering molding method using Cr-containing iron alloy powder or Cr-containing iron alloy powder containing an alloy powder containing at least one metal element of Mn, Ti, and V In addition, since the surface is treated as a mixed layer of a compound layer, a diffusion layer, and a matrix, the surface is treated as a mixed layer of a compound layer, a diffusion layer, and a matrix. Pits are formed and oil pools are formed.In addition, when the wear-resistant parts are operated, a small amount of wear is generated on the soft base portion to form oil pools, and reliability without seizure is improved. High wear parts can be realized.

[0017] Further, when an alloy powder containing at least one metal element of Mn, Ti, and V is used as the iron-based alloy powder containing Cr, the compound layer and the diffusion layer are made of Cr, Mn, Ti, and V. Since at least one component is contained, a predetermined hardness is secured by Fe and Cr, and further the hardness is further improved by the presence of Mn, and the nitriding treatment is promoted by the presence of Ti. Or the presence of V can increase the nitriding depth, further improving the reliability S of the wear-resistant parts.

[0018] Furthermore, a material is formed by compacting and sintering using an iron-based alloy powder containing Cr, and quenching and tempering are performed. Has a mixed structure of a compound layer, a diffusion layer, and a sorbite base structure, so when finishing abrasion-resistant parts, the amount of processing in the soft base part increases, and fine depressions are formed and oil pools are formed. Will do. In addition, when the wear-resistant parts are operated (relative frictional motion), the base material that is softer than the compound layer or the diffusion layer undergoes minute wear and becomes an oil reservoir. More In addition, since the base structure is hardened by quenching and tempering, the compound layer and the diffusion layer are further hardened by nitriding, and it is possible to realize a highly reliable wear-resistant component that does not seize and has higher wear resistance.

[0019] In addition, the material is formed by green compact sintering, quenched and tempered, and then subjected to a nitriding treatment free of carburizing components, and a part of the surface is subjected to a removing force. On the other hand, the surface has a variation in hardness that cannot be achieved by using only the compound layer of FeCrN. Therefore, when finishing the finish, the amount of processing of the soft base portion increases, and a minute depression is formed to form an oil reservoir. In addition, the soft part generates a small amount of wear during the operation (frictional motion during operation), which becomes a pool of oil and improves lubricity, while the wear resistance can be maintained by other compound layer parts. Therefore, the reliability of the wear-resistant parts can be improved.

Brief Description of Drawings

FIG. 1 is a cross-sectional etching photograph of a wear-resistant part according to the present invention.

FIG. 2] An etching photograph of the surface of the wear-resistant part shown in FIG.

FIG. 3] A photograph of a micro-Vickers hardness measurement indentation on the surface of the wear-resistant part in FIG. FIG. 4] A hardness distribution curve of the wear-resistant part of FIG.

FIG. 5 is a chart showing a heat treatment pattern performed on the material of each sample.

FIG. 6 is a photograph showing a surface state of a sample X after nitriding at a magnification of 40.

FIG. 7 is a photograph showing a surface state of a sample Y after nitriding at a magnification of 40.

FIG. 8 is a photograph showing the surface condition of the sample Z after nitriding at a magnification of 40.

FIG. 9 is a photograph showing a surface state of a sample X after nitriding at a magnification of 200.

FIG. 10 is a photograph showing a surface state of a sample X after nitriding at a magnification of 1,000.

FIG. 11 is a photograph showing a surface state of a sample X after nitriding at a magnification of 5,000.

FIG. 12 is a photograph showing a surface state of a sample X after nitriding at a magnification of 20,000.

FIG. 13] A photograph showing the surface state of a sample Y after nitriding at a magnification of 200.

FIG. 14 is a photograph showing the surface condition of a sample Y after nitriding at a magnification of 1,000.

FIG. 15 is a photograph showing a surface state of a sample Y after nitriding at a magnification of 5,000. FIG. 16 is a photograph showing a surface state of a sample Y after nitriding at a magnification of 20,000.

FIG. 17 is a photograph showing a surface state of a sample after nitriding at a magnification of 200.

FIG. 18 is a photograph showing a surface state of a sample after nitriding at a magnification of 1,000.

FIG. 19 is a photograph showing a surface state of a sample after nitriding at a magnification of 5,000.

FIG. 20 is a photograph showing a surface state of a sample after nitriding at a magnification of 20,000.

FIG. 21 is a photograph showing a surface state of another portion of sample 窒化 after nitriding at a magnification of 5,000.

FIG. 22 is a photograph showing a surface state at a magnification of 20,000 of another portion of sample No. 2 after nitriding.

FIG. 23 is a graph showing the maximum concentration of alloying elements in the vicinity of the surface layer of each sample.

FIG. 24 is a graph showing the Ο concentration at the highest concentration portion of the alloy element near the surface layer of each sample.

Explanation of symbols

[0021] 1 hole

2 Compound layer

3 Mixed tissue

8 Micro-Vickers indentation between holes

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The wear-resistant parts to which the present invention is applied are used, for example, as vanes provided on a rolling piston or the like, and are used, for example, for a Cr-containing iron-based alloy powder such as powdered high-speed steel (powder high-speed steel). After forming the material by vacuum sintering at a temperature of about 1200 ° C, a quenching treatment is performed to obtain a martensite structure, and a tempering heat treatment is performed at 480 ° C-580 ° C to obtain a sorbite structure. After that, gas nitriding was performed at 400 ° C below the tempering temperature for about 6 hours with the carburizing component removed.

FIG. 1 shows a cross-sectional structure of the wear-resistant part according to the present invention manufactured as described above after nitriding. The compound layer is etched after gas nitriding to make the compound layer easier to see. You. [0024] Since the material is manufactured by compacting and sintering, the density can only rise to about 80-90%, there are many vacancies 1, and the gas used for nitriding process After passing through, nitriding is performed to the back, and a white compound layer 2 is formed around the vacancy 1. Also, as the distance from the cavity 1 increases, the black portion 3 increases. This is a mixed structure of the diffusion layer and the base.

FIG. 2 shows that the wear-resistant part is cut in a direction perpendicular to the plane of FIG. 1 (that is, cut at a predetermined depth from the surface), and the cut surface is ground to 450 times. It is an enlargement.

[0026] As shown in Fig. 2, a hole 1 peculiar to a green compact is present on the ground surface, and a nitriding gas invades around the hole 1 and nitriding proceeds. The Fe Cr to N compound layer 2 is etched to have a white color. Further, the surface color of the pores 1 is reduced in white color where the surface force is distant, and a mixed structure 3 of a diffusion layer of FeCrN and a matrix is formed. That is, the surface of the wear-resistant article having the pores 1 has a compound layer 2 and a mixed structure 3 of a diffusion layer and a base structure.

FIG. 3 is a photograph of an indentation of the cross section measured by micro Vickers hardness. The smaller the indentation, the harder the micro Vickers hardness !! As is evident from the size of the micro Vickers indentations, the area around hole 1 is relatively small.Between holes 1 and 1, the size of the micro Vickers indentation 8 is smaller than that around the hole. It can be seen that the hardness is greatly reduced. This is because the nitride gas enters around the pores 1 to form the compound layer 2, and the gap 8 between the pores 1 is a mixed structure 3 of the diffusion layer and the matrix. It is considered that it is lower than the periphery of the void 1.

[0028] Since the hardness of the surface is moderately varied as described above, the amount of processing of the soft base portion is increased when finishing the wear-resistant parts, and a fine depression is formed to form an oil pool. Will do. In addition, when the wear-resistant parts are activated, a small amount of wear is generated in the soft base structure portion to serve as an oil reservoir, which has a high wedge effect in addition to the pores of the sintered compact. An oil sump is formed over the entire movable part. Therefore, the oil retentivity of the entire surface is enhanced and lubricity is improved, and the wear resistance can be ensured by the compound layer and the diffusion layer around the pores, so that the entire surface is better than a hard wear-resistant part. Reliability can be secured.

Although the present embodiment has been described with reference to a quenched and tempered product of powdered high-speed steel, the material may be made of a general alloy powder. The same effect can be obtained by manufacturing with an alloy powder containing at least one metal element among Mn, Ti, and V.

FIG. 4 shows a hardness distribution curve of the wear-resistant part of FIG. 1 after the nitriding treatment. Even at the position A exceeding 0.4 mm from the surface, the hardness is almost the same as the surface B. After the surface of the wear-resistant part is ground and removed by about 0.1 mm, the position C at a depth of 0.1 mm from the surface is etched to obtain the sectional structure shown in FIG.

[0031] As described above, the powder sintered compact of the powder noise can be deeply nitrided even if the nitriding treatment is performed for a short time because the material has pores and the nitriding gas easily permeates into the inside. Therefore, in the ordinary nitriding treatment, it is necessary to perform the nitriding treatment after the rough processing of the material, and then to perform a process such as finishing. The required hardness can be easily obtained even if the treatment is performed and the finish processing is performed directly. Furthermore, even if deformation due to quenching and tempering of the material occurs and the stock removal becomes uneven, the variation in surface hardness of the hardest compound layer of the finished product should be small because it is deeply nitrided. Can be.

[0032] Furthermore, by removing the surface, the Fe-Cr

A mixed structure of the N diffusion layer and the matrix appears, which can be understood from the fact that there are low hardness parts even near the surface. In other words, the wear-resistant part according to the present invention can be manufactured at low cost because it can omit the first step while maintaining excellent wear resistance.

Example 1

[0033] Three types of iron-based alloy powders containing Cr are first formed into a predetermined shape, and the formed body is vacuum-sintered at a predetermined temperature (for example, 1180 ° C) to produce a sintered body. After performing a predetermined heat treatment on the sintered body, the surface shape was examined. The material of each sample is equivalent to SKH51, here samples X, Υ, Z and! ヽぅ.

[0034] Table 1 shows the results of composition analysis of Samples X, Υ, and Z after heat treatment.

[Table 1] Unit: wt% WM o then r v l then that genius

r e 寻 Sample X5.5 ~ 4.0 ~ 3.5 ~ 1.4 ~ 0.4 ~ 1.2 ~ ≤1.0

6.7 6.0 5.0 5.0 2.4 0.9.1.8

Sample Y 5.5 to 4.0 to 3.5 to 1.4 to 0.4 to 0.9 to ≤ L 0

6.7 6.0 5.0 5.0 2.4 0.9.1.4

Sample ζ 5.5 to 4.0 to 3.5 to 1.4 to 0.4 to 0.9 to ≤ L 0

6.7 6.0.0 5.0 2.4 0.9.1.4

FIG. 5 shows a heat treatment pattern performed on the material of each sample, and Table 2 shows the material characteristics of each sample.

[Table 2]

[0036] Thereafter, the samples X and Y were subjected to nitriding at a temperature of 400 ° C for 6 hours, whereas the samples Z were subjected to an air treatment at a temperature of 480 ° C for 3 hours (slight Oxidation treatment) and nitriding treatment at 400 ° C for 6 hours.

Next, the surface shape and surface properties of each sample were investigated and evaluated using a scanning electron microscope with a magnification of 40 to 20,000.

[0038] Figs. 6 to 8 show the surface states of the samples X, Υ, and Z after nitriding at a magnification of 40, respectively. Samples Y and Z show the same surface state, whereas samples Y and Z show the same surface state. X has a finer granularity than Samples Y and Z, and an active surface state is observed.

9 to 12 show the surface states of sample X at magnifications of 200, 1,000, 5,000, and 20,000, respectively, and FIGS. , 1,000, 5,000, and 20,000, respectively. 17 to 20 show the surface states of the sample Z at magnifications of 200, 1,000, 5,000, and 20,000, respectively, and FIGS. Surface conditions at magnifications of 5,000 and 20,000 are shown, respectively. [0040] According to Figs. 9 to 12, on the surface of sample X, small grains were pressed and sintered, and countless fine convex precipitates were present on the surface of the sintered grain gap. Precipitation of nitride grains is observed. That is, it can be seen that the inside of the sample X is nitrided by performing the nitriding treatment at a temperature of 400 ° C. for 6 hours.

According to FIGS. 13 to 16, sample Y has a relatively large sintered particle size compared to sample X. As shown in FIGS. 9 and 10 and FIGS. The surface state is exhibited, and even when observed at a magnification of 5,000 or more, the ratio of the fine convex precipitates observed in the sample X is small, and the surface state is stable (inactive).

According to FIG. 17 (magnification 200), the sintered particles on the surface of the sample Z are similar to the sample Y, and are in a larger state than the sample X. However, the magnification shown in FIGS. According to more than 1,000 observations, sample Z has fine precipitates on the surface and sintered grain gaps above sample X, and a microscopic surface condition similar to sample X is formed. .

The difference between sample Y and sample Z lies in the presence or absence of air treatment of the material after sintering. The former is in an untreated state, while the latter is in an air-treated state. The untreated material has a flat and stable state as described above.However, the surface of sample Z that has been treated in the air has an innumerable number of convex precipitates on its surface. I'm active.

On the other hand, the hardness of each sample after nitriding was as shown in Table 3.

[Table 3]

[0045] As shown in Table 3, the hardness at the depths of 0.0 Olmm and 0.05 mm from the surface is higher in the sample ζ, X, and Y in the order of the hardness.

When comparing the hardness shown in Table 3 with the above-mentioned surface shape, the fine precipitates present on the surface after nitriding show the former in the order of samples Z, Y and X as shown in FIGS. 9 to 22. The higher the density. Sample Ζ is treated with air before nitriding the sample It is presumed that the sample Z had a finely precipitated oxide particle particle that activated the surface, thereby facilitating the nitridation reaction.

[0047] In the case of sample Y, the nitriding temperature should be increased (for example, about 430 ° C), or even if the nitriding temperature is 400 ° C, the nitriding time should be extended (for example, about 10 hours). In some cases, the hardness at a depth of 0.5 mm from the surface was increased to 900 Hv or more. Forced nitridation was unstable, and cracks sometimes occurred.

[0048] Further, the sample Z was subjected to atmospheric treatment while changing the treatment temperature to 280 ° C, 380 ° C, 480 ° C, and 580 ° C while keeping the treatment time constant (3 hours). In C, the hardness at the site with a surface force depth of 1.5 mm is less than 900 Hv, but when the processing temperature is 380 ° C or more, the hardness from the surface to the depth of 1.5 mm must be 900 Hv or more. Was confirmed.

[0049] That is, although Samples Y and Z have poor nitridation properties, Sample X was subjected to air treatment at a temperature of 380 ° C for 3 hours, followed by nitriding treatment at a temperature of 400 ° C for 6 hours. Similarly to the above, the nitriding property is improved.

[0050] In each of the samples, differences were found in the alloying elements (Cr, W, Mo, V) and O concentrations near the surface layer, and the differences in these element concentration distributions affected the nitriding reaction.

[0051] More specifically, when the surface composition of each sample was investigated to a depth of about 50 μm, the material having a V ヽ deviation showed almost the same concentration at a depth of 3 μm or more. Based on the data up to a depth of 3 m, the concentration distribution of the elements constituting the surface layer was analyzed.

[0052] As a result, in Sample X, at a depth of about 0.2 µm from the surface layer, a concentrated region of Cr, W, Mo, and V, which was concentrated about 2-3 times the composition of the base material, was observed. In the outermost layer, O content reaching about 30% was detected. The concentration of W, Mo and V in the vicinity of the surface layer of sample Y was about 1.5 times the composition of the base material, but Cr exhibited a deelementization phenomenon. Furthermore, the O concentration in the outermost layer is about 6%, which is lower than that of sample X.

[0053] Similarly to Sample X, Sample Z was formed at a depth of about 0.2 µm from the surface layer, with W and Mo concentrated to about 1.5 to 12 times the base material composition, and with the outermost layer. , About 6% O content was detected. On the other hand, the behavior of Cr and V was similar to that of sample Y, and the former showed the phenomenon of deelementation and the latter showed the phenomenon of enrichment in the outermost layer.

[0054] As described above, the element concentration constituting the surface layer of sample Z has an intermediate aspect between sample X and sample Y. It is assumed that

FIG. 23 shows the maximum concentration of alloying elements in the surface layer of each sample. Sample X has the highest amount of Cr, W, Mo and V in the surface layer. In Samples Y and Z, the amount of Cr is almost the same, but other elements are higher in Sample Z than in Sample Y. From these facts, it is presumed that when nitridation occurs, the specimens X, Z, and Y are more likely to cure in the order of the former.

[0056] Since nitriding of each sample is facilitated by air heating, focusing on the O concentration at the highest concentration site of each alloy element, the graph of Fig. 24 was obtained. According to this graph, excluding the behavior of O concentration at the highest concentration site of V, sample X has a higher concentration of O compared to other samples. On the other hand, sample Y, which is hard to nitride, has the lowest O concentration. From these facts, it is assumed that the level of O concentration at the highest concentration site of Cr, W and Mo generated near the surface layer determines the difficulty of nitriding.

[0057] Note that the O concentration at the highest V concentration site is high in Sample Z because the Z concentration of Sample Z is the highest at the outermost surface, and the other samples have the V concentration higher at the inside than the outermost surface. It is caused by the difference in the absorption of O, and it is assumed that the direct relationship with V is weak.

[0058] According to the present example, as in sample X, fine precipitate particles of nitride cover the surface of sample Z, and the density of sample Z is apparently higher than that of sample X. This determines the order of hardness in the extreme surface layer, and it is presumed that fine precipitates generated by surface shape change due to atmospheric treatment were responsible for nitrogen absorption. In addition, it was observed that almost the entire surface of the sintered material after nitriding of Samples X and Z was covered with particles or projections of about 0.1-0.5 m.

[0059] From the above, samples X and Z can be preferably used as a material for wear-resistant parts according to the present invention, whereas sample Y is not preferable.

Further, from the above, it can be determined as follows.

(1) The surface of the material after nitriding keeps the surface state of the material. Sample X and sample Z have many fine precipitates on the surface. Sample Y has few precipitates and is planar.

(2) The hardness at the depth of 0.05 Olmm and 0.05 mm after nitriding is higher in the order of samples Z, X, and Y, and the surface hardness is related to the density of surface precipitates. (3) The difficulty of nitriding is dominated by the concentration and distribution of alloying elements generated in the surface layer and the surface activation phenomenon of minute oxide particles and the like.

Industrial applicability

In the wear-resistant part according to the present invention, when finishing, the processing amount of the soft base portion is increased, and a minute depression serving as an oil reservoir is formed. Since a pool is formed, it is effective to use it for a sliding part of an engine or a compressor in which abrasion resistance is improved and seizure is not generated.

Claims

The scope of the claims

[1] Using a Cr-containing iron-based alloy powder, the material is formed by compacting and sintering, nitriding is performed to eliminate the carburizing component, and the surface is made of a Fe—CrN compound layer and a Fe—Cr A method for producing a wear-resistant part, characterized by having a mixed structure of a diffusion layer of N and a base.

[2] A material is formed by compacting and sintering using an alloy powder containing at least one metal element of Mn, Ti, and V as an iron-based alloy powder containing Cr to eliminate carburizing components A method for producing a wear-resistant part, characterized in that a nitrided treatment is performed and the surface has a mixed structure of a Fe-Cr-N compound layer, a Fe-Cr ~ N diffusion layer and a matrix.

[3] A vacancy exists on the surface, and a force layer that separates the vacancy from the vacancy is a compound structure of Fe—Cr to N near the vacancy. The method for producing a wear-resistant part according to claim 1 or 2, wherein:

[4] Using a ferrous alloy powder containing Cr, the material is formed by compacting and sintering, and nitriding is performed to eliminate carburizing components. A method for producing a wear-resistant part, comprising a mixed structure of a diffusion layer of ~ N and a base structure of solvite.

[5] There are vacancies on the surface, and the vicinity of the vacancies is a Fe-Cr to N compound layer. 5. The method for producing a wear-resistant part according to claim 4, wherein a mixed structure is used.

[6] The material is formed by green compact sintering, quenched and tempered, then subjected to a nitriding treatment that excludes carburizing components, and a part of the surface is removed, and the surface is treated with at least Fe-Cr. -A method for producing a wear-resistant part, characterized by having a mixed structure including a N compound layer.

7. The method for producing a wear-resistant part according to claim 1, wherein an atmospheric treatment is performed before the nitriding treatment.

[8] The method for producing a wear-resistant part according to claim 7, wherein the atmospheric treatment is performed at a temperature of 380 ° C or higher.

[9] The surface has a Fe-CrN compound layer, a Fe-CrN diffusion layer and a mixed structure of matrix, and almost the entire surface of the sintered material after nitriding is 0.1-0.5. A wear-resistant part characterized by being covered with particles or protrusions of about m.