T10钢金属模具中裂纹电磁热止裂的实验研究

自主设计了改进型ZL-2超强脉冲电流发生装置，采用它对T10金属模具钢中裂纹进行脉冲放电止裂。放电时裂纹尖端熔化形成堆焊和高压应力区，使裂纹尖端钝化，达到了止裂的目的。由于脉冲放电超快速加热和冷却，在裂纹尖端处实现了冲击淬火，得到了超细化的隐晶马氏体和细粒碳化物等微观组织，同时围绕裂纹尖端形成了白亮层组织，提高了裂纹尖端处的硬度、强韧性和耐磨性，实验结果验证了理论研究和数值模拟的结果，为将电磁热裂纹止裂技术应用到金属模具裂纹止裂中，进行了基础实验工艺的研究工作。

Experimental Research on Crack Arrest in Metal Die using Electromagnetic Heating

Crack arrest was executed around the quenching crack tip inside the metal die of T10 steel through pulse current discharge with the new super-density pulse current generator model ZL-2 self designed. The crack tip was melted, welded joints were formed and higher compressive stresses could be produced around the crack tip while the pulse current was switched on. The crack tip was blunted, so the crack can be prevented. Because the heating and cooling was super fast while pulse current was switched on the impulse quenching was achieved around the crack tip. The superfine cryptocrystal martensite and fine-gray carbon compound appeared. The intensity, ductility and wearing capacity around the crack tip were promoted. The results of the theoretical analysis and numerical simulation are verified by experiments. The basic experimental technical research is finished for crack arrest in metal dies using electromagnetic heating.