High-strength hot-dip galvanized steel sheet excellent in formability and method of producing same

US10450626B2 · kind B2 · utility

Assignee

• JFE Steel Corporation · JP

Inventors

• Hiroshi Matsuda · Hiratsuka, JP
• Tatsuya Nakagaito · Tokyo, JP
• Takayuki Futatsuka · Tokyo, JP
• Shusaku Takagi · Tokyo, JP
• Yasunobu Nagataki · Tokyo, JP

Key dates

• Filing date: Mar 17, 2017
• Grant date: Oct 22, 2019
• Expiry date: Jun 13, 2037

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D2211/001
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A high-strength hot-dip galvanized steel sheet excellent in formability includes, on the basis of mass percent, 0.05-0.3% C, 1.4% or less (including 0%) Si, 0.08%-3% Mn, 0.003-0.1% P, 0.07% or less S, 0.1-2.5% Al, 0.1-0.5% Cr, and 0.007% or less N, Si+Al≥0.5%, and the balance being Fe and incidental impurities, wherein the steel sheet has a retained austenite content of 3% or more by volume fraction, a stretch-flange formability λ>50% and wherein the average aspect ratio (major axis/minor axis) of retained austenite grains is less than 2.5.