JM积分在低强钢焊接接头应力腐蚀破裂计算中的应用

运用悬臂弯曲应力腐蚀破裂试验的方法，研究了低强钢焊焊接头的应力腐蚀裂纹的亚临界稳定扩展问题，提出了用弹塑性断裂力学参量ＪＭ描述应力腐蚀理解纹尖端应力应变场。分析了在ＳＣＣ下ＪＭ的计算方法；通过试验与计算测得了焊接接头各区的ｄａ／ｄｔ－ＪＭ曲线，并分析了各区的ＳＣＣ敏感性大小。

THE APPLICATION OF J M INTEGRAL IN PREDICTION OF STRESS CORROSION CRACKING OF LOW STRENGTH STEEL WELDED JOINT

An investigation has been made of stress corrosion crack(SC crack)subcritical stable propagation in low strength steel welded joint in boiling mixed nitrate solution by the use of pre cracked cantilever beam bend speciments.A J like parameter, J M integral, is employed to characterize the stress and strain at the SC crack tip and to predict the crack growth rate d a /d t .A methodological analysis of calculating J M in the condition of stress corrosion cracking(SCC)is given.A group of typical curves of crack growth rate d a /d t vs. J M are obtained.The sensibility of different regions in the welded joint to SCC is also investigated.