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Super-austenitic stainless steel high-temperature homogenization processing method

A technology for austenitic stainless steel and homogenization treatment, which is applied in the field of heat treatment of austenitic stainless steel to achieve the effects of improving thermoplasticity, completely eliminating dendrite structure, improving composition and structure uniformity, and high-temperature thermoplasticity

Active Publication Date: 2017-06-27
NORTHEASTERN UNIV
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

However, there are few reports on the high-temperature homogenization treatment of super austenitic stainless steel

Method used

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  • Super-austenitic stainless steel high-temperature homogenization processing method
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  • Super-austenitic stainless steel high-temperature homogenization processing method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0029] Example 1: Put the cast ingot into a heating furnace, raise the temperature to 1240°C at a rate of 100°C / h, keep it warm for 24 hours, cool down to 1000°C with the furnace, and then take it out of the furnace and air-cool it.

Embodiment 2

[0030] Example 2: Put the cast ingot into the heating furnace, raise the temperature to 1260°C at a rate of 120°C / h, keep it warm for 20h, cool down to 1000°C with the furnace, and then take it out of the furnace and air-cool it.

Embodiment 3

[0031] Example 3: Put the cast ingot into a heating furnace, raise the temperature to 1280°C at a rate of 160°C / h, keep it warm for 16 hours, cool down to 1000°C with the furnace, and then take it out of the furnace and air-cool it.

[0032] After high-temperature homogenization treatment, the homogenization effect can be judged by the following characterization methods:

[0033] (1) Dendrite morphology: Observe the dendrite morphology in the core of the ingot before and after high-temperature homogenization treatment and measure the secondary dendrite spacing.

[0034] (2) Dissolution of Sigma phase: observe the size, quantity and distribution of Sigma phase before and after high-temperature homogenization treatment.

[0035] (3) Mo element segregation coefficient: use electron probe to measure interdendritic and dendrite stem Mo element content, and calculate Mo element segregation coefficient according to element segregation coefficient = interdendritic element content / dend...

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PUM

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Abstract

The invention provides a super-austenitic stainless steel high-temperature homogenization processing method, and aims to improve the uniformity and the high-temperature thermoplasticity of the component and the organization of a cast ingot or cast blank and control the size of crystal grains. The super-austenitic stainless steel high-temperature homogenization processing method is suitable for processing a target grade of steel, wherein the steel comprises, by weight, smaller than or equal to 0.02% of C, smaller than or equal to 4.00% of Mn, 19.5%-25.0% of Cr, 17.5%-23.0% of Ni, 6.0%-8.0% of Mo, 0.18%-0.55% of N, 0.30%-1.00% of Cu, smaller than or equal to 0.80% of Si, smaller than or equal to 0.030% of P, smaller than or equal to 0.01% of S and the balance Fe. The super-austenitic stainless steel high-temperature homogenization processing method is characterized by comprising the steps that the surface of the cast ingot or cast blank is brused with a high-temperature oxidation resistant coating; and the cast ingot or cast blank is put into a heating furnace, heating is conducted at the speed lower than 160 DEG C / h to enable the temperature to the range from 1240 DEG C to 1280 DEG C, the temperature is kept for 16-24 hours, and then hot working is directly conducted, or furnace cooling is conducted to enable the temperature to be 1000 DEG C, and the cast ingot or cast blank is discharged from the heating furnace and cooled in an air-cooling mode. The super-austenitic stainless steel high-temperature homogenization processing method is convenient to use, and reasonable and efficient, obviously eliminates element segregation and dendritic structures of the cast ingot or cast blank, achieves full re-dissolution of the Sigma phase and controls the size of the crystal grains, and therefore the hot-working performance is remarkably improved, and the technical guarantee is provided for acquisition of super-austenitic stainless steel products with high surface quality and excellent performance.

Description

technical field [0001] The invention belongs to the field of heat treatment of austenitic stainless steel, and in particular relates to a high-temperature homogenization treatment method of super austenitic stainless steel. [0002] technical background [0003] Super austenitic stainless steel contains high alloy content (chromium, molybdenum, nickel, nitrogen, etc.), has excellent pitting corrosion resistance, uniform corrosion resistance, stress corrosion resistance and good comprehensive mechanical properties, and is widely used in flue gas desulfurization , nuclear power industry and waste incineration and other very harsh environments. However, the high alloy content makes it easy to redistribute solute during solidification, especially the segregation of Mo content in the liquid phase at the front of the solidification interface is the most serious, and the low diffusion rate of other elements in austenite also aggravates the occurrence of Mo segregation. form. The s...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C21D1/70C22C38/44C22C38/42C22C38/58C22C38/02C22C38/04C22C30/02C21D6/00
CPCC21D1/70C21D6/004C21D2211/001C22C30/02C22C38/001C22C38/02C22C38/04C22C38/42C22C38/44C22C38/58
Inventor 李花兵姜周华张树才张彬彬冯浩朱红春范思鹏苑胜龙
Owner NORTHEASTERN UNIV
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