Thyssenkrupp Steel Europe Ag

Thyssenkrupp Stahl Ag

Thomas Gerber

Janko Banik

Maria Köyer

Jens-Ulrik Becker

Thomas Heller

Andreas Kern

Bernhard Engl

Stefan Myslowicki

Martin Norden

Rainer Fechte-Heinen

Klaus Horn

Sebastian Stille

Dirk Rosenstock

Bernd Linke

Julia Mura

Stefan Krebs

Ilse Heckelmann

Nicolas Vives Diaz

Cássia Castro Müller

Tayfun Dagdeviren

Tim Stötzel

Thomas Niessen

Branko Kuchar

Julia Carolin Mura

A flat steel product is disclosed which is particularly suitable for the production of components for motor vehicle bodies by press-hardening, and which has insensitivity to cracking coupled with increased strength and has sufficient suitability for welding for incorporation into a welded construction. This combination of properties is achieved in accordance with the invention by virtue of the flat steel product having a core layer consisting of a steel alloyed with Mn, B and at least 0.3% by weight of C and having a tensile strength of more than 1500 MPa, and an outer layer cohesively bonded to the core layer. The C content of the outer layer is not more than 0.09% by weight. This flat steel product has, in the region of the outer layer, a tensile strength corresponding to not more than half the tensile strength of the steel of the core layer in the ready-hardened state, with the elongation A80 of the outer layer corresponding to at least 1.5 times the elongation A80 of the core layer in the ready-hardened state.

Sheet steel product, a steel component produced from such a sheet steel product, and body for a motor vehicle

The invention relates to a higher-strength steel strip or steel sheet comprising a predominantly ferritic-martensitic microstructure with a martensite content of between 4 and 20%, wherein the steel strip or steel sheet, apart from Fe and impurities due to smelting, comprises (in % by weight) 0.05-0.2% C, &lE;1.0% Si, 0.8-2.0% Mn, &lE;0.1% P, &lE;0.015% S, 0.02-0.4% Al, &lE;0.005% N, 0.25-1.0% Cr, 0.002-0.01% B. Preferably the martensite content is approximately 5% to 20% of the predominantly martensitic-ferritic microstructure. Such a higher-strength steel strip or steel sheet made from a dual phase steel comprises good mechanical/technological properties even after being subjected to an annealing process which includes an overageing treatment. Furthermore, the invention relates to a method for producing steel strip or steel sheet according to the invention.

High resistance steel band or sheet and method for the production thereof

Growing community of inventors

Dortmund, Germany

Thomas Gerber