800-1600mpa high-strength austenitic stainless steel and its manufacturing method and warm forming method

Abstract

The invention provides 800-1,600 MPa grade high strength austenitic stainless steel, manufacturing method and a warm forming method. The austenitic stainless steel comprises steel chemical components in weight of 0.04%-0.14% of C, 0.2%-0.6% of Si, 2%-12% of Mn, 12%-18% of Cr, 0.5%-6.5% of Ni, less than or equal to 0.03% of P, less than or equal to 0.02% of S, 0.05%-0.25% of N, 0%-2% of Cu, one or more of Mo, Nb and Ti and the balance of Fe and inevitable impurities, and the condition that W(Ni)eq is larger than or equal to 20.5 and smaller than or equal to 25.5 is required to be met. The high strength austenitic stainless steel is obtained by controlling the rolling reduction to be 10%-40% in a rolling process, the tensile resistance is 800-1,600 MPa, and the extension is 13%-40%. At the same time, with the warm forming method, ultra-complex formed high strength stainless steel parts can be obtained, and the high strength austenitic stainless steel has excellent corrosion resistance, high strength and delayed cracking resistance.

Description

technical field [0001] The invention relates to austenitic stainless steel, in particular to an 800-1600MPa high-strength austenitic stainless steel, a manufacturing method and a warm forming method. Background technique [0002] In the lightweight process of automotive products, carbon steel and high-strength steel have been widely used in the automotive industry, and the concept of full life cycle cost of automobiles has gradually penetrated into the automotive industry. Therefore, strict requirements are placed on the service life of automobiles. High strength and corrosion resistance requirements are essential, especially in new energy vehicles, the use of high-strength stainless steel to make the frame and parts can improve the corrosion resistance of the body while reducing the weight of the stainless steel itself to reduce the overall The weight of the vehicle is reduced, and the electrophoresis and other coating processes of carbon steel and high-strength steel are a...

AI Technical Summary

Problems solved by technology

However, these steel types will produce a large amount of deformed martensite and residual stress after being strengthened by cold working.

At the same time, in the subsequent cold deformation process of manufacturing complex parts, the metastable austenitic stainless steel will further induce the generation of martensite and residual stress, as well as the reduction of plastic shape, which affects the progress of further forming. Especially the forming of complex parts; on the other hand, the residual stresses caused by the large amount of deformed martensite increase the risk of delayed cracking of the material

[0004] The difficulty of using deformation-induced martensitic steel-high-strength austenitic stainless steel lies in how to overcome the above two difficulties, and how to reduce the content of deformed martensite and the residual of high-strength stainless steel in the subsequent forming process There is no relevant report on the method of stress generation at home and abroad

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