应变速率对X80管线钢在库尔勒土壤环境中应力腐蚀开裂的影响

Effects of strain rate on stress corrosion cracking of X80 pipeline steel in ku'erle soil environment

利用慢应变速率拉伸试验(SSRT)、动电位扫描及扫描电镜(SEM)技术研究了X80管线钢在库尔勒模拟溶液中应力腐蚀开裂(SCC)行为.结果表明,随着应变速率的增加,X80管线钢在模拟溶液中的腐蚀速率先增大后减小.当应变速率为5×10-7/s时,试样腐蚀较为缓慢,此过程电化学腐蚀起决定性作用;当应变速率为5×10-6/s时,试样的腐蚀情况最为严重,此时力学作用占主导地位.

Slow strain rate testing(SSRT),potention dynamic polarization curves and scanning electron microscope(SEM) were employed to study the stress corrosion cracking(SCC) behavior of X80 pipeline steel in Ku'erle soil simulated solution.The results showed that the corrosion rate of X80 steel first increased and then decreased with the increase of strain rate.When the strain rate was 5×10^(-7)/s,the corrosion phenomenon of X80 steel was not obvious.At this time,electrochemical corrosion played a decisive role.When the strain rate was 5×10^(-6)/s,the corrosion behavior of X80 steel was the most serious.This is due to the combined effects of electrochemical and mechanical on the electrode surface,solution,which the mechanical action was dominating role