1000MPa grade cold rolling hot dip galvanizing two-phase steel and manufacturing method thereof

Abstract

The invention provides 1,000 MPa cold-rolled hot-dip galvanized dual-phase steel and a manufacturing method thereof, belonging to the technical field of cold-rolled hot-dip galvanized high-strength steel plates. The chemical components in mass percentage of the cold-rolled hot-dip galvanized dual-phase steel are: 0.06 to 0.18 percent of C, less than or equal to 0.1 percent of Si, 1.2 to 2.5 percent of Mn,0.05 to 0.5 percent of Mo, 0.05 to 0.6 percent of Cr, 0.005 to 0.05 percent of Al, 0.01 to 0.06 percent of Nb, 0.01 to 0.05 percent of Ti, less than or equal to 0.02 percent of P, less than or equal to 0.01 percent of S, less than or equal to 0.005 percent of N, the balance being Fe and inevitable impurities. The manufacturing method adopts Cr or Mo to replace Si, so as to enlarge an austenitic and ferritic two-phase region and improve the hardenability of the dual-phase steel, and meanwhile, the manufacturing method improves the strength of toughness of the steel by adding Nb or Ti refined grains, so as to ensure that the steel has good weldability and usability, and the strength grade of the steel can reach over 1,000 Mpa.

Description

technical field [0001] The invention relates to the technical field of high-strength steel sheets for cold-rolling and hot-dip galvanizing, and provides a 1000MPa-grade cold-rolling and hot-dip galvanizing dual-phase steel and a manufacturing method thereof. Background technique [0002] In order to reduce the weight of automobiles and achieve the goals of energy saving, environmental protection, and safety, the research and development of advanced high-strength steels such as dual-phase steels has become a focus of attention of scholars from all over the world. Dual-phase steel has the advantages of low yield ratio, high initial work hardening rate, high impact energy absorption capacity, good strength and ductility matching, etc. It is a new high-strength stamping steel with good formability. Duplex steel is widely used in auxiliary parts, body structure, suspension, chassis, etc. of automobiles, among which the body structure is the most used. In the ULSAB program and th...

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Problems solved by technology

At present, cold-rolled hot-dip galvanized dual-phase steel with a strength level of 1000MPa is still blank in China

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