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

US10131976B2 · kind B2 · utility

Assignee

• ThyssenKrupp Steel Europe AG · DE

Inventors

• Dorothée Dorner · Düsseldorf, DE
• Christian Höckling · Duisburg, DE
• Harald Hofmann · Bergneustadt, DE
• Magnus Miller · Duisburg, DE
• Matthias Schirmer · Düsseldorf, DE
• Jonas Schwabe · Duisburg, DE
• Alexander Zimmermann · Aachen, DE

Key dates

• Filing date: Feb 13, 2014
• Grant date: Nov 20, 2018
• Expiry date: Jul 29, 2034

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C22C38/48
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A cold-rolled flat steel product for deep drawing applications is disclosed, composed of a steel which, in addition to Fe and unavoidable impurities (in % by weight) contains C: <0.1%, Al: 6.5-11%, REM: 0.02-0.2%, P: <0.1%, S: <0.03%, N: <0.1% and optionally one or more elements from the group of “Mn, Si, Nb, Ti, Mo, Cr, Zr, V, W, Co, Ni, B, Cu, Ca, N”, provided that Mn: <6%, Si: <1%, Nb: <0.3%, Ti: <0.3%, Zr: <1%, V: <1%, V: <1%, Mo: <1%, Cr: <3%, Co: <1%, Ni: <2%, B: <0.1%, Cu: <3%, Ca: <0.015%. For production of such a flat steel product, a steel of appropriate composition is cast to give a pre-product, which is then hot-rolled to hot strip at a hot rolling end temperature of 820-1000° C. The latter is subsequently wound at a winding temperature of up to 850° C., after winding 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 ≥30% to give the cold-rolled flat steel product and finally annealed at 650-850° C.