Method of thermomechanical shaping a final product with very high strength and a product produced thereby

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 substrate 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;
• thermomechanical shaping of the coated steel sheet substrate to a final product with its final properties;
• wherein the thermomechanical shaping comprises heating the coated steel substrate to a temperature above Ac1 to at least partially austenitise the coated steel substrate, shaping the heated coated steel substrate into a product at elevated temperature and rapid cooling the heated product to obtain the final product with its final properties.

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 blank 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;
• 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.