A production method of high-strength corrosion-resistant austenitic stainless steel plate and strip

Abstract

The invention relates to a production method of high-strength corrosion-resistant austenitic stainless steel plate and strip. Its technical solution is: adopt an "asymmetric cyclic bending deformation device for metal plate and strip", and carry out asymmetric cyclic bending deformation and subsequent annealing treatment on the hot-rolled or annealed austenitic stainless steel strip for 2~ 4 times to refine the grain size of the austenitic stainless steel strip and improve the yield strength of the material; The austenitic stainless steel strip is subjected to asymmetric cyclic bending deformation and subsequent annealing / solution treatment to optimize the distribution of grain boundary characteristics near the surface of the material and improve the corrosion resistance of the material. The invention has the advantages of simple process, easy control and wide applicability, and the produced austenitic stainless steel plate and strip not only has remarkable grain refinement effect, high strength and good matching of strong plasticity, but also has strong corrosion resistance.

Description

technical field [0001] The invention belongs to the technical field of production of austenitic stainless steel plates and strips. In particular, it relates to a production method of high-strength corrosion-resistant austenitic stainless steel plate and strip. Background technique [0002] Stainless steel is widely used in petroleum, chemical industry, aerospace, nuclear industry, cryogenic engineering, marine engineering and other fields. Among them, austenitic stainless steel has strong corrosion resistance and oxidation resistance, excellent welding performance and biocompatibility, and good plasticity. And toughness, its consumption accounts for 70% of stainless steel. However, the yield strength of austenitic stainless steel is low, and its strengthening can only be achieved through fine grains. The average grain diameter of the alloy can be reduced to less than 100nm by using mechanical alloying and spark plasma sintering technology, but the nano Crystalline material...

AI Technical Summary

Problems solved by technology

However, the yield strength of austenitic stainless steel is low, and its strengthening can only be achieved through fine grains. The average grain diameter of the alloy can be reduced to less than 100nm by using mechanical alloying and spark plasma sintering technology, but the nano Crystal material is brittle material, it is difficult to produce strip products

However, nanonization of the surface layer and martensite produced in the near-surface region are relatively effective in improving the strength of thin materials, while the effect of improving the overall mechanical properties of slightly thicker plates and strips by surface mechanical treatment is very limited, and the existence of martensite is still limited. Detrimental effect on the corrosion resistance of austenitic stainless steel plate and strip

[0004] Rolling is the most commonly used and ideal method for industrial production of plates and strips. Hot rolling deformation and recrystallization can refine grains, but because the deformation of each pass is limited by the bearing capacity of the rolling mill, multiple passes of rolling deformation and recrystallization Crystallization can often only refine the grain size to the micron level

Larger total deformation of cold rolling combined with annealing treatment has a very significant effect on refining the grain size of austenitic stainless steel strips, but this method requires many rolling passes, and the large degree of cold rolling deformation is only suitable for strips with small thickness Production

[0005] Grain refinement will inevitably introduce a large number of grain boundaries, increasing (Gr, Fe) 23 C 6 The possibility of precipitation and chromium depletion near the grain boundary increases the sensitivity of grain boundary failure behaviors such as grain boundary cracking and intergranular corrosion. Cold rolling deformation and subsequent annealing treatment are used to greatly increase the proportion of low-energy grain boundaries and realize The optimization of grain boundary feature distribution is the main method to enhance the intergranular corrosion resistance of austenitic stainless steel, but it is difficult to realize the small deformation of cold rolling with the existing thick plate production equipment and technology

The allowable stress of a material is determined by its yield strength. A low yield strength will inevitably lead to bulky structures and equipment, high equipment manufacturing, transportation and installation costs, and is not conducive to the full utilization of materials. The specific surface area of ​​the plate and strip is large, and its resistance Therefore, how to improve the yield strength of austenitic stainless steel sheet and strip while maintaining excellent corrosion resistance has always been a huge challenge for material science and technology workers.

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