Powder metallurgy austenitic stainless steel and preparation method thereof

An austenitic stainless steel, powder metallurgy technology, applied in the field of powder metallurgy materials, can solve problems such as limited application, mechanical properties, wear resistance and corrosion resistance

Active Publication Date: 2018-11-20
SHANDONG UNIV +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, due to the large number of tiny pores inside the powder metallurgy stainless steel, its mechanical properties, wear resistance and corrosion resistance are not as good as the dense stainless steel of the traditional process, which limits its application in some special requirements.

Method used

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  • Powder metallurgy austenitic stainless steel and preparation method thereof
  • Powder metallurgy austenitic stainless steel and preparation method thereof
  • Powder metallurgy austenitic stainless steel and preparation method thereof

Examples

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preparation example Construction

[0025] The invention provides a method for preparing powder metallurgy austenitic stainless steel, comprising the following steps:

[0026] (1) mixing austenitic stainless steel powder, yttrium oxide powder and lubricant to obtain a mixed powder; the quality of the yttrium oxide powder is 0.2% to 0.4% of the total mass of the austenitic stainless steel powder and yttrium oxide powder;

[0027] (2) Compressing the mixed powder obtained in the step (1) to obtain a green body;

[0028] (3) Sintering the green body obtained in the step (2) to obtain powder metallurgy austenitic stainless steel.

[0029] The invention mixes austenitic stainless steel powder, yttrium oxide powder and lubricant to obtain mixed powder. In the present invention, the mass of the yttrium oxide powder is 0.2-0.4% of the mass of the mixed powder, preferably 0.3%. In the present invention, the yttrium oxide powder is used as a stabilizer, which can reduce precipitated phases under high temperature conditi...

Embodiment 1

[0044] Using 99.3wt% of 400-mesh 316L stainless steel powder, 0.2wt% of 400-mesh yttrium oxide powder and 0.5% of zinc stearate as raw materials, a horizontal ball mill is used for dry grinding and mixing. The tank and balls are made of stainless steel. The ratio is 4:1, the rotational speed is 180r / min, and the ball milling time is 1h.

[0045] The uniformly mixed powder is pressed into shape, and the sintered sample used for the electrochemical test is a disc; the one used for the mechanical performance test is a tensile sample, and the size of the tensile sample is as follows figure 2 shown.

[0046] according to figure 1 For the heat treatment curve shown, the pressed sample is heated up to 350°C for 120 minutes under vacuum conditions, held for 30 minutes, then heated to 750°C for 80 minutes, held for 60 minutes, and then heated to 1350°C for 1 hour after 90 minutes. Cool to obtain powder metallurgy austenitic stainless steel.

Embodiment 2

[0048] According to the method of Example 1, the ratio of raw materials was replaced by 99.2wt% of 316L stainless steel powder, 0.3wt% of yttrium oxide powder and 0.5% of zinc stearate.

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Abstract

The invention provides a preparation method of powder metallurgy austenitic stainless steel. The preparation method comprises the following steps that austenitic stainless steel powder, yttrium oxidepowder and a lubricating agent are mixed, and mixed powder is obtained; the then the mixed powder is pressed and sintered in sequence, and the powder metallurgy austenitic stainless steel is obtained.The mass of the yttrium oxide powder accounts for 0.2% to 0.4% of the mass of the mixed powder. The austenitic stainless steel powder and the yttrium oxide powder are adopted as raw materials, a certain amount of yttrium oxide powder is added as a stabilizing agent, and precipitated phases can be reduced at high temperature. Meanwhile, the yttrium oxide powder can be dispersed and distributed ina matrix, matrix grain refinement is achieved, and then the porosity is reduced; and the shape and dimension of occluded foreign substances are improved, the number of the occluded foreign substancesin the steel is reduced, and the number of corrosive pitting inducing sources is effectively reduced. Meanwhile, rare earth oxide in the steel can be effectively desulfurated, the number of the occluded foreign substances in the steel can be reduced, the occluded foreign substances can be modified, and therefore the corrosion resistance of the steel matrix is enhanced.

Description

technical field [0001] The invention relates to the technical field of powder metallurgy materials, in particular to a powder metallurgy austenitic stainless steel and a preparation method thereof. Background technique [0002] The use of stainless steel has derived countless types so far. People purposefully manufacture and use stainless steel with different properties according to the needs of different occasions. Among them, 316 stainless steel is one of the most commonly used steel types. 316 stainless steel (Cr17Ni12Mo2), which contains C≤0.08%, Si≤1.0%, Mn≤2.0%, P≤0.035%, S≤0.03%; and 316L stainless steel (Cr17Ni14Mo2), except that the carbon content is reduced to below 0.03%, The content of other elements is the same as that of 316 stainless steel. 316L stainless steel belongs to the AISI 300 austenitic stainless steel series and appeared in the 1970s. It is a Cr-Ni-Mo type ultra-low carbon stainless steel developed to improve corrosion resistance. It has excellent ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): B22F1/00B22F3/10
CPCB22F3/1007B22F2999/00B22F2998/10B22F1/10B22F2009/043B22F3/02B22F2201/20
Inventor 宫建红李延君李会祥冯胜男刘学男王一喆
Owner SHANDONG UNIV
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