Sheet metal component produced by thermoforming a flat steel product and method for its production

Abstract

The present invention provides a sheet metal member and a method for manufacturing such a sheet metal member which can save energy due to a lower forming temperature compared to a conventionally manufactured sheet metal member at a lower At high strengths an increased residual elongation is achieved and at higher strengths the highest possible cathodic corrosion protection potential is achieved. The composition of the sheet metal component according to the invention is (in weight %): C: up to 0.5%, Si: 0.05-1%, Mn: 4-12%, Cr: 0.1-4%, Al: up to 3.5%, N : up to 0.05%, P: up to 0.05%, S: up to 0.01%, Cu, Ni: up to 2% in total, Ti, Nb, V: up to 0.5% in total, rare earth elements: up to 0.1%, and the rest is Fe and not Impurities to avoid, wherein the content of C in %C and the content of Cr in %Cr satisfy the following condition: (10×%C)+%Cr<5.5%. In order to produce sheet metal components, the flat steel product is heated according to the invention sufficiently to a heating temperature of at least 200° C. and at most 800° C., and the flat steel product heated to the heating temperature is then formed into components by thermoforming, thermoformed sheet metal components 5‑50% by volume of the microstructure consists of austenite, and the remainder consists of martensite, tempered martensite or ferrite, where the ferrite fraction can also be "0", and where the microstructure The average grain diameter of the crystal grains is less than 5 μm.

Description

technical field [0001] The invention relates to a sheet metal component produced by hot forming a flat steel product. [0002] Furthermore, the invention relates to a method for producing the component according to the invention. [0003] If information is given here about the alloy content of the individual elements in the steel according to the invention, it is always relative to weight (expressed in % by weight) unless otherwise stated. [0004] In contrast, data on the structural composition of steel, flat steel products or components formed therefrom are always volume-dependent (expressed in vol. %). If mentioned, here, the proportion of austenite is measured by X-ray diffraction (XRD) with iron-filtered Co-Kα rays. The X-ray diffraction measurement method is described in the following sources: DIN EN 13925 - X-ray diffraction of polycrystalline and amorphous materials, Parts 1 and 2 of the 2003_7 edition, Part 3 of the 2005 edition. If mentioned, other structural comp...

AI Technical Summary

Problems solved by technology

The problem here is that, due to the high austenitization temperature, it is not possible to cathodically protect the plate by a metal anti-corrosion coating

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