Abstract: A method and forming tool for hot forming and press hardening plate-shaped or preformed workpieces of sheet steel, wherein the workpiece is heated to a temperature above the austenitisation temperature and is then formed and quenched in a cooled forming tool having a punch and a female mold, wherein the female mold is coated in its drawing edge region with material in a material-uniting manner and/or is provided there with at least one insert part having a thermal conductivity at least 10 W/(m*K) lower than the thermal conductivity of the portion of the female mold adjacent to the drawing edge region and comes into contact with the workpiece when said workpiece is being hot formed and press hardened, the surface of the material having a transverse dimension within the range of 1.6 times to 10 times the positive radius of the female mold.

Abstract: A method and forming tool for hot forming and press hardening plate-shaped or preformed workpieces of sheet steel, wherein the workpiece is heated to a temperature above the austenitisation temperature and is then formed and quenched in a cooled forming tool having a punch and a female mold, wherein the female mold is coated in its drawing edge region with material in a material-uniting manner and/or is provided there with at least one insert part having a thermal conductivity at least 10 W/(m*K) lower than the thermal conductivity of the portion of the female mold adjacent to the drawing edge region and comes into contact with the workpiece when said workpiece is being hot formed and press hardened, the surface of the material having a transverse dimension within the range of 1.6 times to 10 times the positive radius of the female mold.

Abstract: The invention relates to a method for determining shape changes of a workpiece made of steel or a steel alloy due to forming, in which a varnish is applied to the workpiece, the workpiece is formed and then an optical shape change analysis is carried out by measuring the applied varnish. The object of providing a method for determining shape changes of a workpiece made of steel or a steel alloy, said method also being suitable for analyzing the shape change of a workpiece after hot forming, is solved according to the teaching of the present invention in that before the forming of the workpiece a varnish with an Al proportion of more than 30% by weight is applied to the workpiece, the workpiece is heated for forming to a hot forming temperature and the workpiece is cooled after or during the forming.

Abstract: The invention relates to a method for determining shape changes of a workpiece made of steel or a steel alloy due to forming, in which a varnish is applied to the workpiece, the workpiece is formed and then an optical shape change analysis is carried out by measuring the applied varnish. The object of providing a method for determining shape changes of a workpiece made of steel or a steel alloy, said method also being suitable for analyzing the shape change of a workpiece after hot forming, is solved according to the teaching of the present invention in that before the forming of the workpiece a varnish with an Al proportion of more than 30% by weight is applied to the workpiece, the workpiece is heated for forming to a hot forming temperature and the workpiece is cooled after or during the forming.

Abstract: The invention relates to a process and a measuring apparatus for determining the friction characteristics of sheet metal during forming. To do this, a strip-shaped sample of sheet metal (1) is clamped between two gripping jaws (2, 3) and drawn by a drawing device (9), for preference at a constant drawing speed. During the drawing, the surface pressure (FN)is continually increased. From the values allocated to the surface pressure (FN)and to the drawing force (FZ), applying the known formula &mgr;=FR/FN, the friction characteristics dependent on the surface pressure are calculated.