脉冲电流作用下碳钢淬火裂纹的愈合

THE HEALING OF QUENCHED CRACK IN CARBON STEEL UNDER ELECTROPULSING

对有淬火裂纹的 ４５钢试样进行脉冲电流处理，通过 ＳＥＭ观察处理前后试样的变化结果表明，在脉冲电流作用下．裂纹能够在无熔化的情况下出现愈合，且愈合是在极短时间内发生的.愈合过程不改变材料的原有结构．快速温升引起的瞬时热压应力可能是造成裂纹愈合的重要因素之一．

The specimens of 45 steel with the quenched crack were treated under electropulsing, SEM was employed to examine the change of specimens before and after the treatment. The results show that the crack can be healed under electropulsing without melting, and the healing of crack can be produced within very short time. The original microstructure of specimens is not changed during the healing. It is thought that the transient thermal compressive stress caused by high--rate heating is an important factor causing the healing of crack.