采用慢拉伸(SSRT)、动电位极化和SEM观察等方法, 研究了在不同的阴极保护电位条件下X100钢在酸性土壤模拟溶液中的应力腐蚀行为. 结果表明, X100钢发生穿晶裂纹的应力腐蚀, 裂纹的萌生和发展与阴极保护电位有关. 完全阳极过程控制时, X100钢无裂纹出现, 但出现晶间腐蚀; 在混合过程控制时, 应力腐蚀敏感性较低, 裂纹发展缓慢; 在完全阴极过程控制时, 氢脆机制起主要作用, 裂纹扩展迅速.
Stress corrosion cracking (SCC) of X100 pipeline steel in simulated solutions of acid soil environment located at Yingtan area was investigated by slow strain rate test (SSRT), SEM observation of fracture surfaces and potentiodynamic polarization curves. The results showed that SCC exhibited a transgranular cracking mode. The applied polarization potential played an important role in facilitating SCC. Within anodic potential range, the X100 pipeline steel was controlled by anode process and was insensitive to SCC, but intergranular corrosion appeared. When X100 pipeline steel was controlled by combined anodic and cathodic processes, the stress corrosion sensitivity was low, and the crack grew slowly. But as the applied cathode potential lowered further to a range of only controlled by the cathodic process, hydrogen embrittlement mechanism played the major role and the cracks developed quickly.