Multi-phase steel, cold-rolled flat product produced from such a multi-phase steel and method for producing it

US9970088B2 · kind B2 · utility

Assignee

• ThyssenKrupp Steel Europe AG · DE

Inventors

• Ekaterina Bocharova · Duisburg, DE
• Dorothea Mattissen · Mülheim, DE
• Roland Sebald · Geldern, DE
• Daniel Krizan · Linz, AT
• Andreas Pichler · Steyr, AT

Key dates

• Filing date: Sep 22, 2011
• Grant date: May 15, 2018
• Expiry date: Jul 22, 2033

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C21D2211/008
• WIPO field: Materials, metallurgy
• WIPO sector: Chemistry

Abstract

A multi-phase steel including in % wt. C: 0.14-0.25%, Mn: 1.7-2.5%, Si: 0.2-0.7%, Al: 0.5-1.5%, Cr: <0.1%, Mo: <0.05%, Nb: 0.02-0.06%, S: up to 0.01%, P: up to 0.02%, N: up to 0.01% and optionally at least one of Ti, B, and V according to the following stipulation: Ti: up to 0.1%, B: up to 0.002%, V: up to 0.15%, with the remainder iron and unavoidable impurities, wherein the microstructure has at least 10% vol. ferrite and at least 6% vol. residual austenite and the steel has a tensile strength Rm of at least 950 MPa, a yield point ReL of at least 500 MPa and an elongation at break A80 measured in the transverse direction of at least 15%. A method of producing the multi-phase steel.