Cold-rolled high-strength steel plate having excellent phosphating performance and formability and manufacturing method therefor

US11519046B2 · kind B2 · utility

Assignee

• BAOSHAN IRON & STEEL CO., LTD. · CN

Inventors

• SHU-XIANG ZHOU · Nanhu, CN
• Yong Zhong · Lo Wu, CN
• Xinyan JIN · Shanghai, CN
• Li WANG · Shanghai, CN

Key dates

• Filing date: Aug 29, 2017
• Grant date: Dec 6, 2022
• Expiry date: Jul 5, 2038

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D2211/008
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A cold-rolled high-strength steel plate having excellent phosphating performance and formability and a manufacturing method therefor. The chemical composition of the steel plate is, in percentage by weight, C 0.01-0.20%, Si 1.50-2.50%, Mn 1.50-2.50%, P≤0.02%, S≤0.02%, Al 0.03-0.06%, N≤0.01%, the remainder being Fe and impurities. The surface layer of the steel plate has an inner oxide layer with a thickness of 1-5 μm, and there is no enrichment of Si and Mn on the surface of the steel plate. The steel plate has tensile strength of ≥980 MPa and an elongation of ≥20%. The structure at the room temperature contains retained austenite, ferrite, and martensite and/or bainite.