METHOD FOR CONTACTLESSLY COOLING STEEL SHEETS AND DEVICE THEREFOR

摘要

The invention relates to a method for producing a hardened steel component, wherein a blank is punched out and the punched-out blank is heated to a temperature ≥ Ac3 either completely or in partial regions and is possibly held at said temperature for a predetermined time in order to perform the formation of austenite, and then the blank heated completely or in partial regions is transferred into a forming tool, is formed in the forming tool, and is cooled in the forming tool at a rate that lies above the critical hardening rate and is thereby hardened, or undergoes final cold-forming, and the formed blank is heated to a temperature ≥ Ac3 completely or in partial regions and is possibly held at said temperature for a predetermined time in order to perform the formation of austenite, and then the blank heated completely or in partial regions and formed is transferred into a hardening tool and is hardened in the hardening tool at a rate that lies above the critical hardening rate, wherein the steel material is adjusted to delay conversion in such a way that, at a forming temperature that lies in the range of 450 °C to 700 °C, quench hardening is achieved by conversion of the austenite into martensite, wherein active cooling occurs after the heating and before the forming, in the case of which active cooling the blank or parts of the blank or the formed blank or regions thereof are cooled at a cooling rate > 15 K/s, wherein a cooling device and an object having a hot surface are moved in relation to each other in order to homogeneously, contactlessly cool the hot blanks or components, wherein the cooling device has at least two parallel, spaced cooling blades or cooling columns, wherein the cooling blades or cooling columns have a nozzle edge having nozzles toward the blank to be cooled or toward the component to be cooled, wherein a cooling fluid is directed at the surface of the blank or of the component by the nozzles and the cooling fluid flows away into the intermediate space between the blades or cooling columns after contacting the hot surface.