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

超高强度钢板和模压淬火钢板采用局部电阻加热剪切。通过优化加热条件，使圆剪切区温度均匀，加热后即进行冲裁。在500℃下加热后，冲孔载荷和抛光表面积分别比冷冲孔小1/3左右和大2倍，并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.