METHOD FOR PRODUCING A HOT-FORMED AND HARDENED STEEL COMPONENT COATED WITH A METALLIC ANTI-CORROSION COATING FROM A SHEET STEEL PRODUCT

摘要

The present invention relates to a method for producing a steel component that is coated with a metallic anti-corrosion coating from a sheet steel product comprising at least 0.4 % by weight Mn. In order to economically produce a high-strength steel component while minimising the risk of the development of metal-induced cracks, the invention provides that the sheet steel product is annealed in a continuous furnace under an annealing atmosphere containing up to 25 % by volume H2, 0.1 to 10 % by volume NH3, H20 and N2 as the remainder as well as process-related inevitable impurities at a dew point ranging between -50°C and -5°C at a holding temperature of 400 to. 1100°C for a holding period of 5 to 600 s. The annealed sheet steel product has a 5 to 200 Pm thick nitration layer (N) , the particle size of which is finer than the particle size of the inner core layer (K) of the sheet steel product. Once it has been coated with a metallic protective layer, a blank is separated from the annealed sheet steel product and is heated to an austenitising temperature of 780 to 950°C after an optional preforming step, hot-formed to form the steel component. and cooled so rapidly that a hardened structure forms in the sheet steel product.