Effect of Temperature on Stress Corrosion Cracking Behavior of X70 Pipeline Steel in Alkali Solution

The effect of temperature on stress corrosion cracking (SCC) behavior of X70 pipeline steel in simulated solution of Ku'erle soil was investigated by using sasow strain rate tensile (SSRT) test.The morphology of X70 pipeline steel tensile fracture surface at different temperatures was analyzed by SEM.The results show that temperature had great and complicated influence on SCC behavior of X70 pipeline steel.When the temperature was low (20-30 ℃),X70 pipeline steel had higher sensitivity of SCC with the mechanism of mixture of anodic dissolution and hydrogen embrittlement.When the temperature was higer than 50 ℃,X70 pipeline steel also had higher sensitvity of SCC with the mechanism of cracking caused by corroison film.When the temperature was near 40 ℃,X70 pipeline had lower sensitivity of SCC and the stress corrosion of X70 pipeline steel was mainly in the form of dissolution.