【摘要】 采用慢应变速率拉伸及Devnathan-Stachurski双电解池技术研究了X56钢在模拟海洋大气环境中形变及H₂S含量对其应力腐蚀开裂及氢渗透行为的影响。结果表明,在H₂S含量相同时,拉伸速率越小,试样断裂延伸率越小。在相同拉伸速率下,随着H₂S含量增大,试样断裂延伸率减小,扫描电镜微观分析（SEM）表明,其断裂特征由塑性断裂逐渐转变为脆性断裂。电化学渗氢实验表明,随着H₂S含量的增大,第一干湿循环氢渗透电流并不单调增大,H₂S对氢渗透电流的作用由H₂S的表面覆盖度和腐蚀产物膜来共同控制。从多个干湿循环来看,H₂S可增大氢渗透电流,材料的渗氢加剧,脆性增大。更多还原

【Abstract】 Susceptibility to SCC of X56 grade pipeline steel was investigated by slow strain rate test（SSRT）and Devnathan-Stachurski double electrolytic cell in atmospheric environment containing H₂S.The results showed that the fracture strain decreased while the strain rate decreased in the same H₂S concentration environment. And the fracture strain decreased with increasing the concentration of H₂S at the same strain rate 6.67×10^-7 s^-1.The SEM fractographs of the specimens also showed that the susceptibility to stress corrosion cracking （SCC）increased.The hydrogen permeation test showed that hydrogen permeation current did not increase with increasing the concentration of H₂S in the first wet-dry cycle because of the formation of product film. The longer the experiment time,the more the hydrogen atom permeated through the specimen.This trend partially attribute to the surface coverage ratio（θ）of H₂S and the corrosion product film.更多还原