Patent ID: 8721809

Claim:
Method of thermomechanical shaping a final product with very high strength comprising the steps of: providing a coated hot-rolled and/or cold-rolled steel strip or sheet comprising (all percentages in wt. %): 0.04%<carbon<0.5% 0.5%<manganese<3.5% silicon<1.0% 0.01%<chromium<1% titanium<0.2% aluminium<2.0% phosphorus<0.1% nitrogen<0.015% sulphur<0.05% boron<0.015% unavoidable impurities, balance iron, the steel being coated with a zinc alloy coating layer, wherein the zinc alloy consists of 1.6-2.3% Mg and 1.6-2.3% Al; optionally at most 0.2% of one or more additional elements; unavoidable impurities; the remainder being zinc; cutting the coated steel strip or sheet to obtain a steel sheet blank; thermomechanical shaping of the steel sheet blank to a final product with its final properties; wherein the thermomechanical shaping comprises heating the blank to a temperature above Ac1 to at least partially austenitise the blank, shaping the blank into a product at elevated temperature and rapid cooling the product to obtain the final product with its final properties.