外加电位条件下X100/X80管线钢的应力腐蚀行为研究  

Study on Stress Corrosion Behavior of X100 and X80 Pipeline Steels with Applied Potential

作　　者：黄涛[1] 郭杰[2] 魏开华 陈嘉琦 薛慧勇 王晓峰 HUANG Tao;GUO Jie;WEI Kai-hua;CHEN Jia-qi;XUE Hui-yong;WANG Xiao-feng(Central Iron&Steel Research Institute,Beijing 100094,China;Petrochina Planning and Engineering Institute,Beijing 100083,China)

机构地区：[1]钢铁研究总院有限公司,北京100094 [2]中国石油规划总院,北京100083

出　　处：《材料保护》2023年第3期28-34,共7页Materials Protection

摘　　要：以X100、X80管线钢为研究对象,通过在外加电位条件下的慢应变拉伸速率试验(SSRT),获取管线钢材料在空气中和不同外加电位下的慢拉伸应力腐蚀的应力-应变曲线,分析其应力腐蚀敏感性可知:外加电位对X100和X80管线钢在3.5%NaCl中性溶液中的SCC敏感性和腐蚀开裂机理有显著影响。相同应力腐蚀条件下,X100管线钢的SCC敏感性相对于X80管线钢更低。结合断口微观形貌和极化曲线快、慢扫测试分析X100/X80耐腐蚀性能的特征和差异,可以得出X100和X80管线钢材料在不同外加电位条件下的应力腐蚀机理类型:当外加电位高于-395 mV时,金属处于活化溶解状态;当外加电位置于-395~-462 mV(X80钢)或-395~-504 mV(X100钢)时,机理为膜破裂-阳极溶解(AD)和氢致开裂(HIC)型;如果外加电位进一步降低,机理表现为氢致开裂型。Taking X100 and X80 pipeline steels as research objects,their stress⁃strain curves in air and under different applied potentials were obtained through the slow strain rate tensile test(SSRT).The stress corrosion sensitivity analysis showed that the applied potential had a signif⁃icant effect on the SCC sensitivity and corrosion cracking mechanism of X100 and X80 pipeline steels in 3.5%NaCl neutral solution.Under the same stress corrosion conditions,the SCC sensitivity of X100 pipeline steel was lower than that of X80 pipeline steel.The characteristics and differences of the corrosion resistance of X100 and X80 pipeline steels were analyzed by combing the observation of fracture morphology and fast/slow scan tests of polarization curves,the stress corrosion mechanism type of X100 and X80 pipeline steel materials under different applied potential conditions could be obtained,when the applied potential was higher than-395 mV,the metal was in the state of activation dissolu⁃tion;when the applied potential was-395~-462 mV(X80 steel)or-395~-504 mV(X100 steel),the mechanisms were membrane cracking⁃anodic dissolution(AD)and hydrogen induced crack.If the applied potential further decreased,the mechanism was hydrogen induced crack.

关 键 词：管线钢 应力腐蚀 SCC敏感性 X100管线钢 X80管线钢 

分 类 号：TG172.8[金属学及工艺—金属表面处理]