Flat steel semi-finished product, method for producing a component, and use thereof

Abstract

A semifinished flat steel product (1) includes a first layer (1.1) of a martensitic steel alloy having a tensile strength of >1200 MPa and / or a hardness of >370 HV10, and at least one second layer (1.2, 1.2′) of a soft steel alloy having a tensile strength of <600 MPa and / or a hardness of <190 HV10 which is fully and cohesively bonded to the first layer (1.1).

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is the U.S. National phase of, and claims priority to, International Application No. PCT / EP2018 / 054372, filed Feb. 22, 2018, which designated the U.S. and which claims priority to DE Application No. 10 2017 203 507.2, filed Mar. 3, 2017. These applications are each incorporated herein by reference in their entireties.TECHNICAL FIELD[0002]The invention relates to embodiments of a semifinished flat steel product comprising a first layer and at least one second layer fully and cohesively bonded to the first layer. The invention further relates to processes for producing a component from the semifinished flat steel product and to corresponding uses.TECHNICAL BACKGROUND[0003]There is a search in the automobile industry for new solutions for reducing vehicle weight and accordingly for reducing fuel consumption. Lightweight construction is an essential tool here to be able to lower vehicle weight. One way of achieving this is th...

AI Technical Summary

Benefits of technology

The patent is about improving the properties of semi-finished flat steel products that can be easily coated and have a lower tendency to crack during forming operations. These products also have a higher bending angle. The patent also describes processes for producing components and their uses.

Problems solved by technology

However, the bending capacity of materials generally decreases with rising strength.

However, steel alloys having an essentially martensitic microstructure (martensite-phase steels), owing to their chemical and physical properties, are only of limited coatability, especially with an anticorrosion coating.

Since shaping capacity decreases with increasing strength, which is especially at the expense of bending angle, it is possible for microcracks / cracks to form in the surface or in the near-surface region of the steel material in the forming operation, depending on the geometry or complexity to be established, and these can lead in the worst case to premature component failure.

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