电磁热效应对T7钢的裂纹止裂

Crack Preventing by the Elcetromagnetic Heat Effect on Crak in Steel T7

利用电磁热效应原理 ,在自制的 ZL- 1型超强度脉冲电流发生装置上 ,对 T7钢的裂纹止裂效果进行了初步研究。结果表明 :对试件实施放电瞬间 ,在裂纹尖端处形成焊口 ,使裂纹尖端的曲率半径增大 ,达到抑制裂纹扩展的目的。同时 ,对裂纹尖端热影响区的组织进行了分析 ,并讨论了因快速加热和冷却作用所获得细小淬火马氏体组织及热压应力和相变压应力对止裂效果的影响。

By using theory of electromagnetic heat effect,the effect on crack preventing for steel T7 was studied on instrument of super intention pulses electric current generator.The results show that a small welded joint can be formed at a small sphere near the top of the crack by smelting as the result of heat concentration effect,when the time electromagnetic is applied.This result can be used to crack preventing.At same time,the microstructure of the front top of the crack was studied.The influence of fine martensite and the hot stress and phase stress because of high heat and cooling rate on effect of crack preventing was discussed,too.