阅读说明：本技术 一种高密度、高硬度真空烧结不锈钢材料及其加工工艺 (High-density and high-hardness vacuum sintering stainless steel material and processing technology thereof ) 是由 申承秀 于 2020-07-10 设计创作，主要内容包括：本发明涉及粉末冶金技术领域,具体涉及一种高密度、高硬度真空烧结不锈钢材料及其加工工艺,所述不锈钢材料包括18.0％～20.0％的Cr、8.0％～12.0％的Ni、以及余量为Fe的微量元素。本发明通过将铜粉、镍粉和铁元素混合后制成不锈钢材料,并经过混合、压制成形、烧结、整形等工艺加工而成；经测试,烧结体的密度达到7.2g/cm<Sup>3</Sup>以上,硬度超过60HRB,其硬度达到客户要求,经用户试装,产品无变形,满足使用要求。(The invention relates to the technical field of powder metallurgy, in particular to a high-density and high-hardness vacuum sintering stainless steel material and a processing technology thereof, wherein the stainless steel material comprises 18.0-20.0% of Cr, 8.0-12.0% of Ni and the balance of trace elements of Fe. The invention mixes copper powder, nickel powder and iron element to produce stainless steel material, andthe material is processed by the processes of mixing, press forming, sintering, shaping and the like; the density of the sintered body reaches 7.2g/cm through testing 3 The hardness exceeds 60HRB, the hardness meets the requirements of customers, and the product has no deformation after trial assembly by users and meets the use requirements.)

1. The high-density and high-hardness vacuum sintering stainless steel material is characterized by comprising, by mass, 18.0-20.0% of Cr, 8.0-12.0% of Ni and the balance of trace elements of Fe.

2. The high-density high-hardness vacuum-sintered stainless steel material according to claim 1, further comprising a lubricant, wherein said lubricant is lithium stearate, and said lubricant is 1.5% by weight of the stainless steel material.

3. The process for processing high-density and high-hardness vacuum-sintered stainless steel material according to claim 2, comprising the steps of:

(1) preparing powder, namely mixing Cr, Ni and Fe elements, atomizing, ball-milling and sieving to prepare stainless steel material mixed powder;

(2) mixing, press forming, namely putting the stainless steel material mixed powder into a die for press forming to prepare a stainless steel blank;

(3) and (4) sintering, namely placing the stainless steel blank in a special stainless steel vacuum furnace for sintering, and then cooling to obtain a stainless steel material sintered body.

(4) Shaping, the stainless steel material sintered body is deburred, and then press-shaped using a press die to have a predetermined shape and a predetermined dimensional accuracy.

4. The processing technology of the high-density and high-hardness vacuum sintering stainless steel material as claimed in claim 3, wherein in the step (1), the grain size of the stainless steel material mixed powder is 45-110 um.

5. The process for manufacturing a high-density and high-hardness vacuum-sintered stainless steel material according to claim 3, wherein before the step (2), a lubricant is added to the mixed powder of the stainless steel material, and the mixture is ball-milled and mixed by using a three-dimensional motion mixer, wherein the rotating speed is 12 rpm, and the time is 45 minutes.

6. The processing technology of vacuum sintering stainless steel material with high density and high hardness as claimed in claim 3, wherein the pressure for pressing the stainless steel material mixed powder in step (2) is 600-700 MPa.

7. The processing technology of claim 3, wherein in the step (3), the inert gas is introduced into the stainless steel vacuum furnace as a protective atmosphere, and the sintering temperature is 1120-1280 ℃, and the cooling temperature is 600-800 ℃.

Technical Field

The invention relates to the technical field of powder metallurgy, in particular to a high-density and high-hardness vacuum sintering stainless steel material and a processing technology thereof.

Background

The powder metallurgy stainless steel is the stainless steel manufactured by a powder metallurgy method, has the advantages of reducing alloy element segregation, refining microstructure, improving performance, saving materials, saving energy consumption, reducing cost, and can be widely applied to the fields of automobiles, household appliances, medical appliances and the like. The powder metallurgy stainless steel powder has poor compressibility and is pressed at normal temperature, the density of a green body is only about 6.8g/cm3 after conventional vacuum sintering, and the apparent hardness is about 30 HRB. Because the product has low hardness, the product is easy to deform after being assembled, and the use requirement cannot be met. If the boat pushing furnace and ammonia decomposition are adopted as protective atmosphere for sintering, the hardness meets the requirement, the product is not deformed after assembly, but due to the generation of nitride during sintering, foreign matters splash during subsequent assembly, are adsorbed on mating parts, and the function of the product is seriously influenced, so that the sintering mode cannot be adopted.

In order to expand the application field of the powder metallurgy stainless steel and promote the further development of the powder metallurgy stainless steel technology and the production process, the optimization of the current production process is urgently needed, the hardness and the density after vacuum sintering are improved, and the sintering density of the material reaches more than 7.2g/cm3 and the hardness reaches more than 60HRB, so that the material can be applied to products with high requirements on density, hardness and strength, such as air conditioners, medical instruments and the like.

Disclosure of Invention

The invention mainly aims to provide a high-density and high-hardness vacuum sintering stainless steel material and a processing technology thereof.

In order to achieve the purpose, the invention adopts the following technical scheme: a high-density and high-hardness vacuum sintering stainless steel material comprises, by mass, 18.0% -20.0% of Cr, 8.0% -12.0% of Ni and the balance of trace elements of Fe.

Preferably, the stainless steel material further comprises a lubricant, wherein the lubricant is lithium stearate, and the lubricant accounts for 1.5% of the total weight of the stainless steel material.

The invention also provides a processing technology of the high-density and high-hardness vacuum sintering stainless steel material, which comprises the following steps:

(1) preparing powder, namely mixing Cr, Ni and Fe elements, atomizing, ball-milling and sieving to prepare stainless steel material mixed powder;

(2) mixing, press forming, namely putting the stainless steel material mixed powder into a die for press forming to prepare a stainless steel blank;

(3) and (4) sintering, namely placing the stainless steel blank in a special stainless steel vacuum furnace for sintering, and then cooling to obtain a stainless steel material sintered body.

(4) Shaping, the stainless steel material sintered body is deburred, and then press-shaped using a press die to have a predetermined shape and a predetermined dimensional accuracy.

Preferably, in the step (1), the grain diameter of the stainless steel material mixed powder is 45um to 110 um.

Preferably, before the step (2), the lubricant is added into the stainless steel material mixed powder, and a three-dimensional motion mixer is used for ball milling and mixing, wherein the rotating speed is 12 r/min, and the time is 45 min.

Preferably, in the step (2), the pressure for pressing the stainless steel material mixed powder is 600-700 MPa.

Preferably, in the step (3), an inert gas is introduced into the stainless steel vacuum furnace as a protective atmosphere, the sintering temperature is 1120-.

Compared with the prior art, the invention has the following beneficial effects:

the invention relates to a high-density and high-hardness vacuum sintering stainless steel material and a processing technology thereof, wherein copper powder, nickel powder and iron are mixed to prepare the stainless steel material, and the stainless steel material is processed by the processes of mixing, press forming, sintering, shaping and the like; the density of the sintered body reaches 7.2g/cm through testing³The hardness exceeds 60HRB, the hardness meets the requirements of customers, and the product has no deformation after trial assembly by users and meets the use requirements.

Detailed Description

The technical solutions of the present invention will be described in further detail with reference to several preferred embodiments, and it should be apparent that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. It is to be noted that the following examples are intended to facilitate the understanding of the present invention, and do not set forth any limitation thereto. All other embodiments, which can be obtained by a person skilled in the art without any inventive step based on the embodiments of the present invention, are within the scope of the present invention. The test methods in the following examples, which are not specified under specific conditions, are generally carried out under conventional conditions.

A high-density and high-hardness vacuum sintering stainless steel material comprises, by mass, 18.0% -20.0% of Cr, 8.0% -12.0% of Ni and the balance of trace elements of Fe.

Preferably, the stainless steel material further comprises a lubricant, wherein the lubricant is lithium stearate, and the lithium stearate accounts for 1.5% of the total weight of the stainless steel material.