Procedure for homogeneous non-contact annealing of non-infinite surfaces to be tempered and apparatus for this

摘要

A method for producing a hardened steel component in which a sheet blank is stamped out and the stamped sheet blank is heated to a temperature ≥Ac3 and as needed, is kept at this temperature for a predetermined time in order to carry out the austenite formation and then the sheet blank, which has been heated all over or only in some regions, is transferred to a forming die, is formed in the forming die, and in the forming die, is cooled at a speed that lies above the critical hardening speed and is thus hardened or else the sheet blank is completely cold formed and the formed sheet blank is heated all over or only in some regions to a temperature Ac3 and as needed, is kept at this temperature for a predetermined time in order to carry out the austenite formation and then the sheet blank, which has been heated and formed all over or only in some regions, is transferred to a hardening die, and is hardened in the hardening die at a speed that lies above the critical hardening speed; the steel material is adjusted in a transformation-delaying way so that at a forming temperature that lies in the range from 450° C. to 700° C., a quench hardening takes place through the transformation of the austenite into martensite; after the heating and before the forming, an active cooling takes place in which the sheet blank or parts of the sheet blank is/are cooled at a cooling speed of 15 K/s; for the homogeneous, contactless cooling of hot sheet blanks or components, a cooling apparatus and an article with a hot surface are moved relative to each other; the cooling apparatus has at least two cooling blades or cooling columns that are parallel to and spaced apart from each other; oriented toward the sheet blank to be cooled or the component to be cooled, the cooling blades or cooling columns have a nozzle edge with nozzles; the nozzles direct a cooling fluid at the surface of the sheet blank or the component and after the cooling fluid contacts the hot surface, it flows away in the space between the blades or cooling columns.