Steel with multi-scale twin-crystal structure and preparation method of steel

A multi-scale, structural steel technology, applied in the field of crystal structure steel and its preparation, can solve the problems of difficult preparation of fine twins, and achieve the effects of high wear resistance, good thermal stability and simple preparation process

Inactive Publication Date: 2013-05-22
UNIV OF SHANGHAI FOR SCI & TECH
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, high-density fine twins are difficult to prepare in engineering materials
At present, high-density nano-twinned thin film materials, such as copper foil with a thickness of tens of microns, can only be prepared under extremely harsh conditions (Science, 2009, 323, 607, Mater. Sci. Eng. A 2006, 429, 272)

Method used

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  • Steel with multi-scale twin-crystal structure and preparation method of steel
  • Steel with multi-scale twin-crystal structure and preparation method of steel
  • Steel with multi-scale twin-crystal structure and preparation method of steel

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0040] The preparation of AISI 304 stainless steel plate with multi-scale twin structure, the steps are as follows:

[0041] Put the AISI 304 stainless steel plate with a thickness of 1mm into the pretreatment chamber of the high-speed impact equipment, and control the strain rate to 5′10 4 m / s, the impact velocity is 7m / s, and after surface mechanical grinding at room temperature 23 ℃ for 10min, the AISI 304 stainless steel plate with multi-scale twin structure can be obtained.

[0042] The AISI 304 stainless steel plate with multi-scale twin structure obtained above was examined by transmission electron microscope (JEM 2010, Japan JEOL Electronics Co., Ltd.), scanning electron microscope (HITACHI S-4200, Japan Hitachi) and X-ray diffraction instrument (Bruker D8, Germany Bruker) conducted observations, and the results showed that its microstructure is nano- and sub-micron scale twins, nanocrystals and a￠martensite;

[0043] The AISI 304 stainless steel plate with multi-scal...

Embodiment 2

[0050] The preparation of AISI 304 stainless steel plate with multi-scale twin structure, the steps are as follows:

[0051] Put the AISI 304 stainless steel plate with a thickness of 1mm into the pretreatment chamber of the high-speed impact equipment, and control the strain rate to 8′10 6 m / s, the impact velocity is 19m / s, and the room temperature is 23°C. After surface mechanical grinding for 20min, the AISI 304 stainless steel plate with multi-scale twin structure is obtained.

[0052] The above-mentioned AISI 304 stainless steel plate with multi-scale twin structure was analyzed by XRD (Bruker D8, Bruker, Germany) instrument, and its surface microstructure was composed of austenite with a volume fraction of 94% and a￠ with a volume fraction of 5%. Composed of martensite and 1% e martensite.

[0053] The above obtained AISI 304 stainless steel plate with multi-scale twin structure was measured by transmission electron microscope (JEM 2010, Japan JEOL Electronics Co., Ltd....

Embodiment 3

[0056] The preparation of AISI 301 stainless steel plate with multi-scale twin structure, the steps are as follows:

[0057] Put the AISI 301 stainless steel plate with a thickness of 1 mm into the pretreatment chamber of the high-speed impact equipment, and control the strain rate to 2′10 2 m / s, the impact velocity is 3m / s, and after cooling with liquid nitrogen at -80°C for 1min, the AISI 301 stainless steel plate with multi-scale twin structure is obtained.

[0058] The AISI 301 stainless steel plate with multi-scale twin structure obtained above was observed by transmission electron microscopy (JEM 2010, JEOL Electronics Co., Ltd., Japan) and XRD (Bruker D8, Bruker, Germany) instruments. Its microstructure is twins, nanocrystals, a￠martensite and e martensite, the volume fraction of a￠martensite is 26%, the volume fraction of e martensite is 8%, and the volume fraction of g austenite is 66%.

[0059] The above-mentioned AISI 301 stainless steel plate with multi-scale twin...

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Abstract

The invention discloses steel with a multi-scale twin-crystal structure and a preparation method of the steel. The steel with the multi-scale twin-crystal structure is of a complex microstructure, i.e., a multi-scale twin-crystal and complex phase structure, and the hardness of the steel is reduced in a gradient way from the surface to the center. The preparation method comprises the step of preparing the steel by taking austenitic stainless steel, TRIP (Transformation-Induced Plasticity) steel or TWIP (Twinning Induced Plasticity) steel as materials by using a high strain rate deformation method or high strain rate deformation and temperature deformation treatment combined method. The twin-crystal density of the multi-scale twin-crystal structure ranges from 10% to 90% and changes along with the change of depth, and the twin-crystal density of a surface layer of the multi-scale twin-crystal structure ranges from 30% to 85%, and the twin-crystal density of the center of the multi-scale twin-crystal structure ranges from 10% to 50%. The strength and the plasticity of the steel with the multi-scale twin-crystal structure, disclosed by the invention, are synchronously enhanced; and meanwhile, the favorable ductility is kept. The steel has the highest yield strength of 900-1800MPa, the tensile strength of 1000-2000MPa and the breaking elongation of 30-50%.

Description

technical field [0001] The invention relates to a steel with multi-scale twin structure and a preparation method thereof. Its microstructure is characterized by nano / submicron scale twins, which are characterized by high strength and high toughness. Background technique [0002] The continuous development of high-performance structural steels is driven by increasing safety and energy-saving requirements, especially in the automotive and aerospace industries. Steel strengthening techniques include adding alloying elements, creating a multiphase structure and refining the grain size to nanocrystalline or ultrafine grains, etc. However, the increase in strength is often accompanied by a decrease in plasticity, or even deterioration. Stainless steel has been used in various structures due to its excellent workability, corrosion resistance, and strength, among others. Strengthened stainless steels generally include cold work hardening stainless steels, precipitation hardening ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21D8/00
Inventor 陈爱英潘登贾彦全刘芳
Owner UNIV OF SHANGHAI FOR SCI & TECH
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