Nanometer/ultrafine crystal structure ultrahigh-strength plasticity austenitic stainless steel and preparation method

Abstract

The invention discloses nanometer / ultrafine crystal structure ultrahigh-strength plasticity austenitic stainless steel and a preparation method, and belongs to the field of ultrahigh-strength plasticity alloy steel production. Raw materials comprise the following chemical components: 0.08-0.15% of C, 0.35-0.75% of Si, 7.5-10% of Mn, 0.5-0.9% of Cu, 1-1.5% of Ni, 14-16% of Cr, 0.1-0.25% of N, P notmore than 0.06%, S not more than 0.03%, and the balance of iron and inevitable impurities. After smelting by a vacuum induction furnace, a casting blank is forged, and a forging is hot rolled; twicecold rolling annealing is performed after the solid solution treatment; a nanometer / ultrafine crystal composite structure is obtained by using reversion of strain induction martensite and recrystallization of deformation austenite. The ultrahigh-strength plasticity of stainless steel is realized through fine crystal strengthening, back stress reinforcement, deformation induction twins effect and deformation induction martensite effect. The prepared stainless steel is prominent in comprehensive mechanical performance; the yield strength reaches 1150-1320 MPa, and is 3.2-4.5 times in an originalsolid solution state; the tensile strength reaches 1350-1440 MPa; the ductility still achieves a higher level of 39.2-47.3%; the cost is lower; and the preparation method is simple and feasible.

Description

technical field [0001] The invention belongs to the field of ultra-high-strength plastic alloy steel production and relates to a nano / ultra-fine-grain structure ultra-high-strength plastic austenitic stainless steel and a preparation method thereof. Background technique [0002] Calcium phosphate and bioactive glass are commonly used biomedical bone materials. Although they can promote the formation of bone tissue, their application is limited due to their low strength, the bending strength is only in the range of 42-200MPa, and they are fragile. Austenitic stainless steel has been widely used in biomedical materials such as artificial joints due to its non-magnetic properties, corrosion resistance and easy formability. For example: "Research and Application of Medical Nickel-free Stainless Steel" published in "Acta Metals" Vol. 53, No. 10, pp. 1311-1316 in October 2017 and published in "Metal Heat Treatment" Vol. 38 in January 2013, No. 1, pp. 15-20, "Research status and p...

AI Technical Summary

Problems solved by technology

However, although nanocrystalline materials have high strength and toughness, their work hardening ability and uniform elongation are significantly reduced, especially when the grain size drops below 100nm, the uniform elongation is significantly lower than that of the original material, and many nanocrystalline materials even Their fracture stresses are already reached during the elastic phase of the tensile deformation process, which severely limits their application as structural materials

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