中文摘要：

应用自制的ZL-2超强脉冲电流发生装置，对带有半埋藏裂纹的45钢拉伸试样进行了拉伸载荷作用下的脉冲放电电磁热止裂；对止裂前后的拉伸试样通过微机控制电子万能试验机进行了三点弯曲试验，并对止裂前后裂尖附近的显微组织进行了对比分析。结果表明：电磁热止裂后，裂纹尖端瞬时熔化、钝化，达到了裂纹止裂的目的；在裂纹尖端附近的组织出现了细化，电磁热止裂后试样所能承受的最大弯曲力和抗弯强度分别较止裂前提高了约23％和25％。

英文摘要：

45 steel tensile specimens with half-embedding cracks were used to perform pulse discharge crack arrest experiment using a self-made ZL-2 super pulse current generation device. The three-point bending test was carried on the tensile specimens before and after the crack arrest using a computer control electronic universal testing machine. The microstructure near the crack tip was analyzed. The results show that the crack tip was instantly melt and dulled after pulse current discharge, resulting in crack arrest. The microstructure around the crack tip was refined. The maximum bending force and bending strength of specimens after crack arrest was improved by 23 % and 25% compared specimens before arack arrest respectively.