阅读说明：本技术 粉末冶金用析出硬化型不锈钢粉末、复合物、造粒粉末及析出硬化型不锈钢烧结体 (Precipitation hardening stainless steel powder for powder metallurgy, compound, granulated powder, and precipitation hardening stainless steel sintered body ) 是由 中村英文 工藤纯一 于 2020-02-27 设计创作，主要内容包括：本发明提供一种粉末冶金用析出硬化型不锈钢粉末、复合物、造粒粉末及析出硬化型不锈钢烧结体。该粉末冶金用析出硬化型不锈钢粉末供于利用酸脱脂法的脱脂时可以抑制因氧化引起的特性劣化,其特征在于,Fe为主要成分,以3.00质量％以上且5.00质量％以下的比例包含Ni,以15.00质量％以上且17.50质量％以下的比例包含Cr,以3.00质量％以上且5.00质量％以下的比例包含Cu,以0.15质量％以上且0.45质量％以下的比例包含Nb,以0.30质量％以上且1.00质量％以下的比例包含Si,以Si含量与Mn含量的质量比Si/Mn为2.00以上且6.00以下的比例包含Mn,供于利用酸脱脂法的脱脂。(The invention provides a precipitation hardening stainless steel powder, a compound, a granulated powder and a precipitation hardening stainless steel sintered body for powder metallurgy. The precipitation hardening stainless steel powder for powder metallurgy is capable of suppressing deterioration of characteristics due to oxidation when being subjected to degreasing by an acid degreasing method, and is characterized in that Fe is a main component, Ni is contained in a proportion of 3.00 mass% or more and 5.00 mass% or less, Cr is contained in a proportion of 15.00 mass% or more and 17.50 mass% or less, Cu is contained in a proportion of 3.00 mass% or more and 5.00 mass% or less, Nb is contained in a proportion of 0.15 mass% or more and 0.45 mass% or less, Si is contained in a proportion of 0.30 mass% or more and 1.00 mass% or less, and Mn is contained in a proportion of 2.00 or more and 6.00 or less in terms of a mass ratio of Si/Mn of the Si content to the Mn content, and is subjected to degreasing by the acid degreasing method.)

1. A precipitation hardening stainless steel powder for powder metallurgy, characterized in that,

the main component of the Fe is Fe,

ni is contained in a proportion of 3.00-5.00 mass%,

contains Cr in a proportion of 15.00-17.50 mass%,

cu is contained in a proportion of 3.00-5.00 mass%,

nb is contained in a proportion of 0.15 to 0.45 mass%,

si is contained in a proportion of 0.30 to 1.00 mass%,

mn is contained in a mass ratio of Si content to Mn content, Si/Mn being 2.00 or more and 6.00 or less,

for degreasing by an acid degreasing method.

2. The precipitation hardening stainless steel powder for powder metallurgy according to claim 1,

the mass ratio of the O content to the Si content, O/Si, is 0.10 to 0.90.

3. The precipitation hardening stainless steel powder for powder metallurgy according to claim 1 or 2,

when the Si content is s, the Mn content is m, and the Cr content is c, s/{ m + (c/10) } is 0.15 or more and 0.50 or less.

4. The precipitation hardening stainless steel powder for powder metallurgy according to claim 1,

the content of O is 0.01 to 0.70 mass%.

5. The precipitation hardening stainless steel powder for powder metallurgy according to claim 1,

the average particle diameter is 0.50 to 50.00. mu.m.

6. A composite, characterized in that,

comprises the following steps:

the precipitation hardening stainless steel powder for powder metallurgy according to any one of claims 1 to 5; and

and a binder for binding the particles of the precipitation hardening stainless steel powder for powder metallurgy to each other.

7. A granulated powder characterized by containing, as a main component,

the precipitation hardening stainless steel powder for powder metallurgy according to any one of claims 1 to 5 is granulated.

8. A precipitation hardening stainless steel sintered body characterized in that,

the precipitation hardening stainless steel powder for powder metallurgy according to any one of claims 1 to 5 is sintered.

9. A precipitation hardening stainless steel sintered body characterized in that,

the main component of the alloy is Fe,

ni is contained in a proportion of 3.00-5.00 mass%,

contains Cr in a proportion of 15.00-17.50 mass%,

cu is contained in a proportion of 3.00-5.00 mass%,

nb is contained in a proportion of 0.15 to 0.45 mass%,

si is contained in a proportion of 0.30 to 1.00 mass%,

the mass ratio of the Si content to the Mn content, Si/Mn, is 2.00 or more and 6.00 or less, and contains Mn,

precipitates containing silicon oxide are precipitated on the surface.

Technical Field

The present invention relates to a precipitation hardening stainless steel powder for powder metallurgy, a compound, a granulated powder, and a precipitation hardening stainless steel sintered body.

Background

In the powder metallurgy method, a composition obtained by including a metal powder and a binder is formed into a desired shape, an obtained molded body is degreased to obtain a degreased body, and the degreased body is fired to produce a sintered body. In the process of producing such a sintered body, the particles of the metal powder are subject to an atomic diffusion phenomenon, and the compact is gradually densified and sintered.

In such a powder metallurgy method, when the compact is degreased, the binder is thermally decomposed and removed by heating the compact. However, since the removal of the binder requires a long time for heating, there are problems that the production efficiency is lowered and the molded body is easily deformed during heating.

Thus, patent document 1 discloses that a molded body obtained by heating a metal material powder and a binder containing a polyoxymethylene resin in an acid-containing atmosphere is degreased. Thus, by performing the degreasing treatment under an acid-containing atmosphere, the binder can be effectively removed because the acid decomposes the binder. Therefore, the above-described problems can be reduced.

In the degreasing treatment described in patent document 1, for example, the molded body is heated in an atmosphere containing nitric acid to remove the binder contained in the molded body. However, the metal powder contained in the molded body is easily oxidized when the metal powder is contacted with nitric acid. Therefore, when the degreased body in which the metal powder is oxidized is baked in the subsequent baking step, there is a problem that the sinterability of the metal powder is lowered, or the corrosion resistance and the mirror surface property of the sintered body after sintering are lowered.

Patent document 1: japanese laid-open patent publication No. 4-247802

Disclosure of Invention

A precipitation hardening stainless steel powder for powder metallurgy according to an application example of the present invention is characterized in that,

the main component of the Fe is Fe,

ni is contained in a proportion of 3.00-5.00 mass%,

contains Cr in a proportion of 15.00-17.50 mass%,

cu is contained in a proportion of 3.00-5.00 mass%,

nb is contained in a proportion of 0.15 to 0.45 mass%,

si is contained in a proportion of 0.30 to 1.00 mass%,

mn is contained in a mass ratio of Si content to Mn content, Si/Mn being 2.00 or more and 6.00 or less,

for degreasing by an acid degreasing method.

Detailed Description

Embodiments of the precipitation hardening stainless steel powder, the composite, the granulated powder, and the precipitation hardening stainless steel sintered body for powder metallurgy according to the present invention will be described in detail below.

Precipitation hardening stainless steel powder for powder metallurgy

First, precipitation hardening stainless steel powder for powder metallurgy according to the embodiment will be described.

In the powder metallurgy technique, after a composition containing a metal powder and a binder is formed into a desired shape, a sintered body of the desired shape can be obtained by degreasing and baking. Such a powder metallurgy technique has an advantage in that a sintered body having a complicated and fine shape can be produced in a near-net shape, that is, a shape close to a final shape, as compared with other techniques.

In addition, the degreasing treatment is a treatment of decomposing by heating and removing the binder, and by performing this treatment under an acid-containing atmosphere, the binder can be effectively removed. Such a degreasing method is particularly called an acid degreasing method.