Cold-rolled flat steel product for deep drawing applications and method for production thereof

US10513762B2 · kind B2 · utility

Assignee

• ThyssenKrupp Steel Europe AG · DE

Inventors

• Evgeny Balichev · Düsseldorf, DE
• Harald Hofmann · Bergneustadt, DE
• Jose Jimenez · West Hollywood, US

Key dates

• Filing date: Feb 13, 2014
• Grant date: Dec 24, 2019
• Expiry date: Oct 13, 2035

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D2211/005
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A cold-rolled flat steel product for deep drawing applications including in addition to Fe and unavoidable impurities (in % by weight) C: 0.008%-0.1%, Al: 6.5%-12%, Nb: 0.1%-0.2%, Ti: 0.15-0.5%, P: <0.1%, S: <0.03%, N: <0.1% and optionally one or more elements from the group of Mn, Si, REM, Mo, Cr, Zr, V, W, Co, Ni, B, Cu, Ca, N, where 2.5≥% Ti/% Nb≥1.5. Also a method of producing such a flat steel product including casting a pre-product, which is then hot-rolled into a hot strip with a hot rolling end temperature of 820-1000° C. and wound at a winding temperature of up to 750° C. After winding, the hot strip is annealed at an annealing temperature of >650-1200° C. for 1-50 h, then cold-rolled in one or more stages with a total cold rolling level of ≥65% and finally annealed at 650-850° C.