摘要
在波形膨胀节环焊缝接头裂纹处直接取样，进行金相、电镜等检验，结合焊接接头处工作状态的应力分析，结果表明这是一种应力腐蚀裂纹．
By means of optical microscope and transmission electron microscope, the crack of the welded joint of waved expanding link was studied. The stressing of the welded joint was analysed.It was founded that this crack is stress-corrosion one.
