Development of shearing process of ultra-high strength steel sheets using local resistance heating

对超高强度钢板和模压淬火钢板进行了局部电阻加热剪切。通过优化加热条件，获得了圆形剪切区内的均匀温度，并在加热后立即对该区域进行冲压。在500℃加热条件下，冲压载荷约为冷冲压的1/3，磨光面积约为冷冲压的2倍，防止了冲孔周围延迟断裂的发生。

Ultra-high strength steels sheets and die-quenched steel sheets were sheared by local resistance heating. Uniform temperature in the circular shearing zone was obtained by optimizing heating conditions, and the zone was punched just after the heating. For heating at 500℃of the die-quenched sheet, the punch load and the burnished surface area were about 1/3 smaller and 2 times larger than those for the cold punching, respectively, and the occurrence of delayed fracture around the punched hole was prevented.