The stress corrosion cracking (SCC) of ERW pipes was studied in mixed nitrate slotion (MNS) at 90℃ σ impSCC (the critical stress of SCC) and W ASCC (the critical fracture energy of SCC) of the four pipe line steels and their weld metals were measured by notched tension specimen. The anodic polarization behavior of the researched materials was investigated by potentiondynamic fast-slow scanning polarization technique. The crack tip morphology and fracture surface of SCC were analyzed by the...