High-purity ferrite stainless steel material and manufacturing method thereof

Abstract

The invention discloses high-purity ferritic stainless steel, which comprises the following chemical compositions in percentage by weight: less than or equal to 0.025 percent of C and N, less than or equal to 0.50 percent of Si, less than or equal to 0.50 percent of Mn, less than or equal to 0.03 percent of P, less than or equal to 0.01 percent of S, 18 to 20 percent of Cr, less than or equal to 0.30 percent of Ni, 1.75 to 2.00 percent of Mo, 0.25 to 0.40 percent of Nb, less than or equal to 0.015 percent of O, 0.01 to 0.10 percent of rare earth elements, 0 to 0.10 percent of other elements, and the balance being balance element Fe. The manufacturing process of the high-purity ferritic stainless steel comprises processes such as smelting, casting, cogging of casting ingots or casting blanks, hot rolling, annealing and acid-washing after the hot rolling, cold rolling, annealing and acid-washing after the cold rolling. The high-purity ferritic stainless steel can improve the plasticity of welding seams.

Description

technical field [0001] The invention relates to the field of stainless steel products and its manufacture, in particular to a high-purity ferritic stainless steel material capable of improving the performance of welded parts and its manufacturing method. Background technique [0002] Ferritic stainless steel, especially the medium and high Cr series high-purity or ultra-pure ferritic stainless steel with low C and N content is more and more popular because it is different from the traditional high C and N content. Compared with ferritic stainless steel, its corrosion resistance and processing performance have been greatly improved, and its comprehensive performance is no less than that of nickel-containing austenitic stainless steel in many applications. However, when ferritic steel is used as a structural part, the coarse grains at the weld of ferritic steel cannot be avoided during the welding process, and the coarse grains lead to the increase of hot crack sensitivity and...

AI Technical Summary

Problems solved by technology

The disadvantage of this invention patent is that the addition of Ti in the smelting process will lead to poor fluidity of the molten steel in the continuous casting process, and the clogging of the nozzle will lead to a low billet rate of the molten steel; the size of Al oxides and Ti nitrided precipitates cannot be effectively controlled during the welding process , It is difficult to implement; at the same time, the invention patent does not involve the addition of rare earths, nor does it involve the effect of rare earth elements, and the main chemical composition C: 0.015%, N: 0.020%, Nb: 0.36% or less, Ti: 0.15% or less , Cr: 24 to 32%, Mo: less than 4%, which belongs to high-chromium ferritic stainless steel, which is different from the medium-chromium high-purity ferritic stainless steel of this application in terms of composition and control method

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