Method for producing a high-strength flat steel product

US10280477B2 · kind B2 · utility

Assignees

• ThyssenKrupp Steel Europe AG · DE
• thyssenkrupp AG · DE

Inventors

• Alexander Gaganov · Mülheim an der Ruhr, DE
• Wolfgang Gervers · Duisburg, DE
• Andreas Kern · Roth, DE
• Gabriel Kolek · Witten, DE
• Elena Schaffnit · Düsseldorf, DE
• Hans-Joachim Tschersich · Dorsten, DE

Key dates

• Filing date: Mar 18, 2015
• Grant date: May 7, 2019
• Expiry date: Sep 21, 2035

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D2211/002
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

Methods for producing flat steel product with a yield strength of at least 700 MPa and an at least 70% by volume bainitic microstructure may comprise several steps. For example, one method may involve smelting a steel melt including in percent by weight 0.05-0.08% C, 0.015-0.500% Si, 1.60-2.00% Mn, 0.025% P, up to 0.010% S, 0.020-0.050% Al, up to 0.006% N, 0.40% Cr, 0.060-0.070% Nb, 0.0005-0.0025% B, 0.090-0.130% Ti, unavoidable impurities, and Fe. The may further involve casting the melt to give a slab, reheating the slab, rough-rolling the slab, hot finish-rolling the rough-rolled slab, cooling the hot-finish-rolled flat steel product within ten seconds of hot finish-rolling, and coiling the hot-finish-rolled flat steel product.