Medium-chromium ferrite stainless steel for automobile with high formability and acidic corrosion resistance as well as manufacturing method thereof

Abstract

The invention relates to medium-chromium ferrite stainless steel for automobiles with high formability and acidic corrosion resistance, comprising the following components in percentage by weight: not more than 0.015 percent of C, not less than 0.20 percent and not more than 0.05 percent of Si, not less than 0.20 percent and not more than 0.07 percent of Mn, 16.0 to 18.0 percent of Cr, not more than 0.03 percent of P, not more than 0.002 percent of S, not more than 0.3 percent of Ni, not more than 0.015 percent of N, not more than 0.025 percent of C+N, not more than 0.06 percent of Al, not more than 0.2 percent of Cu, 0.1 to 0.3 percent of Zr, and the balance of Fe and inevitable impurities; one or more of Nb and Ti are also added as stabilizing elements with the following addition amount: Nb single stabilization: 0.5Nb is not less than 0.10 percent and not more than 0.20 percent by weight; Ti single stabilization: Ti is not less than 8X(C+N) and not more than 0.30 percent by weight, wherein the 8X(C+N) is not less than 0.20 percent by weight; Nb, Ti dual stabilization: 0.5Nb+Ti is not less than 10X(C+N) and not more than 15(C+N); Nb / Ti is equal to 1.0 to 1.8; and Nb + Ti is not more than 0.40 percent by weight. The medium-chromium ferrite stainless steel adopts different stabilizing modes of Ti single stabilization, Nb single stabilization and Ti + Nb dual stabilization and adds the stabilizing elements with different contents according to different stabilizing modes.

Description

technical field [0001] The invention relates to stainless steel for automobiles and a manufacturing method thereof, in particular to a medium chromium ferritic stainless steel with high formability and acid corrosion resistance for automobiles and a manufacturing method thereof. Background technique [0002] With the development of the national economy, the automobile industry has developed rapidly in recent years. More and more stringent environmental protection requirements and the need to continuously reduce the weight of the vehicle body and the cost of materials have made the materials used in automobile exhaust systems more and more valued by automobile manufacturers. Ferritic stainless steel has the advantages of comprehensive cost and performance such as nickel saving, excellent corrosion resistance, low thermal expansion coefficient, high strength and other physical and mechanical properties, making ferritic stainless steel replace austenitic stainless steel as the ...

AI Technical Summary

Problems solved by technology

Generally, low chromium (11Cr) stainless steel cannot meet the requirements of use and cannot reach the life guarantee period

The existing stainless steel with medium chromium generally contains Mo, Cu, etc., which can improve the corrosion performance, but the improvement of performance also increases the material production cost and management cost

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