SCC behavior of X80 steel welded joint in mechanical and electrochemical effects

Potentiondynamic polarization curves and slow strain rate testing(SSRT) were used to study the stress corrosion cracking(SCC) behavior of welded joint for X80 pipeline steel in Ku'erle soil simulated solution. Fracture appearances at different strain rate were analyzed by SEM. The results showed that the corrosion rate of welded joint increases persistently with the increase of strain rate. When the strain rate is 1×10^-5/s, the corrosion of welded joint is the most serious. The influence of stress on electrochemical corrosion plays a decisive role of welded joint. The specimen fractures at the welded joint after SCC, which is caused by lattice defects in the welded joint.