Powder stainless steel reinforcing and sintering method

A technology for strengthening sintering and stainless steel, applied in the field of powder metallurgy, it can solve the problems of reducing the plasticity and ductility of the material, and having too many pre-alloyed elements, so as to improve the thermoplasticity and hot workability, improve the corrosion resistance, and improve the resistance to intergranular corrosion. Effect

Inactive Publication Date: 2004-01-28
UNIV OF SCI & TECH BEIJING
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  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

While effectively increasing the density of powder metallurgy structural materials, it solves the problem that the previously added sintering aids will reduce the plasticity and ductility of the material, or there are too many pre-alloying elements, making it suitable for actual production

Method used

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  • Powder stainless steel reinforcing and sintering method
  • Powder stainless steel reinforcing and sintering method
  • Powder stainless steel reinforcing and sintering method

Examples

Experimental program
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Effect test

example 4

[0022] Example 4: The dense austenitic 316L stainless steel powder product has good plasticity, and the elongation rate reaches 30%, while the general powder sintered steel is below 3-5%, which is a brittle material. Whether the material formed by powder sintered stainless steel high-density pressing and sintering with activator is plastic or brittle is very important for structural parts and has an important impact on subsequent processing performance.

[0023] The invention uses compression deformation to judge whether the plasticity of the powder sintered stainless steel is high-density pressed and sintered with the addition of an activator is good or bad. Depress the sample to a certain height (about 40% of the total height of the sample) to see if there are macroscopic cracks. The compression pressure required for each sample at 40% reduction is as follows figure 1 shown.

[0024] From figure 1 Look, when the reduction is the same, 4# sample, 6# sample, and 9# sample r...

example 5

[0025] Therefore, the addition of Fe-Mo-B not only improves the sintering strength of 316L stainless steel powder compact, but also improves the plasticity of the material within a certain range; while Cu 3 Although the addition of P improves the sintering strength of the 316L stainless steel powder compact, it sacrifices the plasticity of the material and even makes it a brittle material. Example 5: An important indicator for evaluating the performance of powdered stainless steel parts is to determine the quality of its corrosion resistance. Usually in a certain concentration of NaCl or various acidic media such as H 2 SO 4 、HNO 3 and HCl to determine the corrosion type of stainless steel.

[0026] An important factor restricting the development of powder stainless steel structural parts is the low density of the parts, which means that there are a large number of residual pores inside the parts. These residual pores, especially the interconnected pores, not only signific...

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Abstract

The forced sintering method of powder 316L stainless steel is characterized by that in the product a proper quantity of sintering activating agent Cu3P or Fe-Mo-B whose component composition is reasonable is added, and a reasonable sintering process is made. The activating agent is Cu3P 2-8 wt% or Fe-Mo-B 2-8 wt%, P content is Cu3P is 13-14%, Mo content in Fe-Mo-B is 30-55%, and B content is 2-5%, sintering activating agent can be premixed into 316L stainless steel powder, they are ground by using ball-grinding machine, and its sintering temp. is 1200-1350 deg.C. Said invention also provides the concrete steps of heating to sintering temp. and cooling to room temp.

Description

technical field [0001] The invention belongs to the technical field of powder metallurgy, and in particular provides a method for strengthening sintering of powdered 316L stainless steel. Background of the invention [0002] Whether powder metallurgy 316L stainless steel parts can replace dense 316L stainless steel parts depends on two main factors: its strength and corrosion resistance. Usually, there is a certain amount of residual porosity inside the structure of powder metallurgy structural parts. These residual porosity reduce the strength of the part. The powder metallurgy process continues to develop, and technologies such as warm pressing, mold wall lubrication and alloying can largely eliminate these residual pores and increase the strength of the material. The main references are: Rutz H G, Harejjo F G, Luk S H. "Warm Compaction Offers High Density at LowCost". MPR, 1994, 49(9): 40-47, etc. [0003] Adding sintering aids for sintering is the most widely used, ea...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C22C33/02
Inventor 果世驹杨霞陈邦峰胡学晟魏延平
Owner UNIV OF SCI & TECH BEIJING
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