A high-formability low-chromium ferritic stainless steel and its manufacturing method

Abstract

The invention discloses a high formability and low-chromium ferrite stainless steel and a making method thereof, the high formability and low-chromium ferrite stainless steel comprises the following chemical components by weight: less than or equal to 0.015% of C, 0.010-0.35% of Si, 0.015-0.25% of Mn, 9.5-11% of Cr, 0.15-0.20% of Ti, less than or equal to 0.025% of P, less than or equal to 0.002% of S, less than or equal to 0.010% of N, less than or equal to 0.025% of (C + N), 0.0010-0.0050% of Ca, less than or equal to 0.05% of Al, greater than or equal to 6 (C + N) of Ti, and balance of Fe and inevitable impurities, wherein the impurity element Ni content is less than or equal to 0.3%, Cu content is less than or equal to 0.3%, O content is less than or equal to 0.0050%, and the content of Ni+0.5Cu is less than or equal to 0.35%, and the total amount of other impurity elements is less than 0.05% of. The formability is improved by reduction of hardness and strength by reduction of the Cr, Si and Mn content and control of solid solution amount of the Cr, Si and Mn in the steel to reduce the solid solution strengthening effect; by strict control of the content of Ni and Cu, the possibility of the martensite phase formation is reduced to reduce the hardness and strength of the stainless steel to improve the formability. By control of mixed use ratio of molten iron and scrap steel, the content of the impurity elements Ni and Cu in the steel, the influence of the impurity elements Ni and Cu on the hardness and strength and other properties can be ultimately controlled.

Description

Technical field [0001] The present invention relates to a ferritic stainless steel and a manufacturing method, in particular to a high-formability low-chromium ferritic stainless steel and a manufacturing method. The product of the present invention can also be applied to other pairs under the premise of meeting certain high temperature resistance and oxidation resistance. In environments with high formability requirements, it is especially suitable for the production of small pipe diameter products such as motorcycle exhaust pipes or products with high formability requirements, including 6-8 grades of grain size. Background technique [0002] Traditional motorcycle exhaust systems are made of carbon steel or carbon steel aluminized plates. At present, due to the pressure of environmental protection, higher requirements are put forward on motorcycle exhaust emissions. Major domestic motorcycle industries, environmental protection enterprises and related scientific research Focusi...

AI Technical Summary

Problems solved by technology

[0006] Most existing patented technical solutions ensure the plasticity and corrosion resistance of the material by adding more Nb, Ti, V, Al, rare earth and other elements, but too many of these alloy elements will significantly improve The alloy cost and manufacturing cost of the material also increase the strength and surface hardness of the material, and there is no clear research on the influence of the content of residual elements such as Ni and Cu on the material performance

Images