High-strength intergranular-corrosion-resistant twinning induced plastic austenitic stainless steel

Abstract

High-strength intergranular-corrosion-resistant twinning induced plastic austenitic stainless steel comprises, in percentage by weight, the chemical components of <=0.02% of C, 1.00%-3.00% of Si, 22.00%-28.00% of Mn, <=0.015% of P, <=0.010% of S, 2.00%-4.00% of Ni, 16.00%-20.00% of Cr, 0.4%-0.8% of N and the balance of Fe and inevitable impurities. After solution treatment at the temperature of 1,050-1,150 DEG C, an obvious TWIP effect can be generated under cold deformation not less than 5%, the tensile strength is 850-950MPa, the yield strength is 450-550MPa, the ductility is greater than orequal to 50%, and sensitized intergranular corrosion cracks do not exist according to a GB / T4338 E method test. The stainless steel has the advantages that the problems of insufficient corrosion resistance of TWIP stainless steel and insufficient strength of common 300-series stainless steel are solved; and after solution treatment, high strength and high corrosion resistance can be obtained at the same time.

Description

technical field [0001] The invention relates to the technical field of austenitic stainless steel, in particular to a high-strength intergranular corrosion-resistant twin-induced plastic austenitic stainless steel. Background technique [0002] Twin-induced plasticity, or TWIP effect, refers to strain-induced deformation twins, cutting and refining grains, thereby causing the Hall-Petch effect, which can not only increase the strength, but also promote the transfer of strain to lower regions, resulting in uniform and necking Extend and improve plasticity. TWIP steel is a major breakthrough in iron and steel materials. It can obtain high strength and plasticity at the same time. The strength-plastic product is generally above 50GPa.%. It has great application value in aviation, aerospace, automobile industry, petrochemical and other fields. [0003] The strengthening of TWIP steel comes from the TWIP effect, and whether the TWIP effect occurs or not depends mainly on the sta...

AI Technical Summary

Problems solved by technology

Since the C content is less than 0.03%, the strength of ultra-low carbon austenitic stainless steel is not high, so it cannot be used as a load-bearing structural part

Although the existing Cr-TWIP stainless steel has high strength, its intergranular corrosion resistance is insufficient, and it is difficult to apply it to acidic environments. At present, corrosion-resistant bearing parts mostly use high-cost corrosion-resistant alloys

It can be seen that the prior art steel grades cannot simultaneously realize high strength, intergranular corrosion resistance and cost controllability. The present invention designs a new material on the basis of the prior art steel grades, which is equivalent to 304L in corrosion resistance and comparable to that of 304L. TWIP stainless steel has the same strength, realizes the matching of high strength and intergranular corrosion resistance, and the cost is controllable. It is a candidate material for corrosion-resistant and bearing structural parts in the petrochemical field.

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