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Preparation method of high-strength and high-plasticity 304 austenitic stainless steel with low martensite content

A technology of austenitic stainless steel and 304 stainless steel, used in the field of metal material strengthening, can solve the problems of harsh process technology, low processing efficiency, and limited wide application, so as to avoid radar tracking, reduce magnetic flux leakage, and increase torsional strain. Effect

Active Publication Date: 2020-03-27
INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, due to the current development of several surface deformation processes such as surface mechanical grinding and surface rolling treatment technology, it is necessary to use hard alloy cutter heads with special geometric dimensions to perform high-speed grinding or rolling treatment on the metal surface, and the process technology is harsh. low processing efficiency
More importantly, the surface of 304 austenitic stainless steel samples processed by this type of deformation technology still contains a high-density martensitic structure, which severely limits its wide application in industrial environments with magnetic fields

Method used

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  • Preparation method of high-strength and high-plasticity 304 austenitic stainless steel with low martensite content
  • Preparation method of high-strength and high-plasticity 304 austenitic stainless steel with low martensite content
  • Preparation method of high-strength and high-plasticity 304 austenitic stainless steel with low martensite content

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Experimental program
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Effect test

Embodiment 1

[0033] In this embodiment, the coarse-grained 304 austenitic stainless steel bar is subjected to small-angle cyclic reciprocating torsional deformation treatment.

[0034] Fix one end of the coarse-grained 304 austenitic stainless steel sample, and apply cyclic torsional deformation to the other end (such as figure 1 Shown), the gradient structure 304#1 sample was obtained.

[0035] The process parameters of the gradient structure 304#1 sample are selected as follows: the diameter of 304 austenitic stainless steel is 6 mm, the torsion angle amplitude is 5 degrees, the torsion speed is 9000° / min, the torsion cycle is 200 cycles, and the torsion time is about 14 seconds. The temperature is room temperature 25 degrees.

[0036] As the depth from the surface increases, the degree of deformation in the material presents a monotonically decreasing trend, forming a gradient distribution of deformation microstructure ( figure 2 ). However, the microstructure is still austenite and...

Embodiment 2

[0039] In this embodiment, a cyclic torsional deformation treatment is applied to the coarse-grained 304 austenitic stainless steel #2 sample to obtain a 304 #2 sample with a gradient structure.

[0040] The difference from Example 1 is that the process parameters of the gradient structure 304#2 sample are selected as follows: the diameter of 304 austenitic stainless steel is 6 mm, the torsion angle amplitude is 15 degrees, the torsion speed is 9000 ° / min, and the torsion cycle is 200 cycles , the torsion time is about 6 minutes, and the torsion temperature is 25 degrees at room temperature.

[0041] As the depth from the surface increases, the degree of deformation in the material presents a monotonically decreasing trend, forming a gradient distribution of deformation microstructure ( figure 2 ). The outermost surface is still coarse-grained ( Figure 4 ), there are high-density dislocations distributed inside the coarse grain, a large number of dislocation cells and disl...

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Abstract

The invention discloses a preparation method of high-strength and high-plasticity 304 austenitic stainless steel with low martensite content, and belongs to the technical field of metal material strengthening. According to the method, small-angle circulating and reciprocating torsional deformation treatment is conducted on a coarse-grain 304 stainless steel bar or pipe, so that dislocation and nano twin crystal deformation microstructures distributed in a gradient mode are introduced into an original coarse-grain structure of 304 stainless steel, and meanwhile, the martensite structure contentof the surface layer of the material is less than 7%; the small-angle cyclic torsional deformation treatment means that one end of the bar or the pipe is fixed, and a force is applied to enable the other end of the bar or the pipe to rotate around the center axis of the bar or the pipe in a reciprocating mode, so one-time reciprocating rotation is one cyclic torsional cycle. Compared with a uniform coarse grain structure with the same components, the material treated by the circulating torsion process is improved by more than 1.5 times in the yield strength, and the metal material has uniformplasticity equivalent to that of coarse grains.

Description

technical field [0001] The invention relates to the technical field of strengthening metal materials, in particular to a method for preparing high-strength and high-plasticity 304 austenitic stainless steel with low martensite content. Background technique [0002] 304 austenitic stainless steel, as the most widely used austenitic stainless steel, has the advantages of high toughness, plasticity, easy machinability and good corrosion resistance, and is widely used in aerospace, petrochemical, transportation, etc. All industrial fields. In recent years, with the development of society, resources are increasingly scarce, energy consumption and environmental pollution are intensifying, which forces metal components and equipment to continue to develop in the direction of high performance, light weight, energy saving and environmental protection, and the service environment is becoming more and more complex. However, the yield strength and hardness of austenitic 304 stainless s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21D7/10
CPCC21D7/10C21D2211/001C21D2211/008
Inventor 卢磊潘庆松崔方
Owner INST OF METAL RESEARCH - CHINESE ACAD OF SCI
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