中文摘要：

采用电化学动电位极化技术、慢应变速率拉伸（SSRT）实验和SEM对X80管线钢在鹰潭土壤模拟溶液中的应力腐蚀行为进行了研究.结果表明：X80管线钢在酸性土壤环境中具有较高的SCC敏感性,其断口模式为穿晶SCC;SCC机制随外加电位的不同而改变,在外加电位高于-930 mV时,其SCC机制由阳极溶解和氢致腐蚀两种电极过程控制,呈现阳极溶解和氢脆复合机制;当电位低于该电位时,其SCC为氢脆机制.随着外加阴极电位的降低,X80管线钢的SCC敏感性不断增大;与X70钢相比,氢脆作用在X80管线钢SCC过程中发挥了更重要的作用.

英文摘要：

Stress corrosion cracking（SCC） of X80 pipeline steel in a simulated solution of the acidic soil environments in Yingtan China was studied by means of potentiodynamic polarization curves,slow strain rate test（SSRT） and corrosion morphologies characterized by SEM.The results show that X80 pipeline steel has high SCC susceptibility in the simulated solution and the failure mode is transgranular cracking.The SCC mechanism would vary with the applied cathodic potential. When the applied potential is positive to about -930 mV,the SCC behavior is controlled by the combined effect of anodic dissolution（AD） and hydrogen embrittlement（HE）,i.e.the SCC mechanism is AD＋HE.However,when the applied potentials are lower than—930 mV,such as—1000 and—1200 mV, the process of hydrogen evolution plays the dominant role in SCC occurrence,meaning that the SCC mechanism is HE under such applied potentials.Moreover,SCC susceptibility increases with decreasing applied cathodic potential.Compared with X70 pipeline steel in acidic soil environments,HE plays a more important role in affecting SCC occurrence.