High-strength galvanized steel sheet having excellent formability and crashworthiness

US9290834B2 · kind B2 · utility

Assignee

• JFE Steel Corporation · JP

Inventors

• Hiroshi Hasegawa · Ome, JP
• Tatsuya Nakagaito · Tokyo, JP
• Shinjiro Kaneko · Tokyo, JP
• Yasunobu Nagataki · Tokyo, JP
• Yoshitsugu Suzuki · Tokyo, JP

Key dates

• Filing date: Oct 7, 2011
• Grant date: Mar 22, 2016
• Expiry date: Oct 7, 2031

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10T428/12972
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A galvanized steel sheet has a composition containing, by mass %, C: 0.05% or more and 0.5% or less, Si: 0.01% or more and 2.5% or less, Mn: 0.5% or more and 3.5% or less, P: 0.003% or more and 0.100% or less, S: 0.02% or less, Al: 0.010% or more and 0.5% or less, B: 0.0002% or more and 0.005% or less, Ti: 0.05% or less, a relationship of Ti>4N being satisfied, and the balance comprising Fe and inevitable impurities, and a microstructure containing 60% or more and 95% or less of tempered martensite in terms of area ratio and 5% or more and 20% or less of retained austenite in terms of area ratio.