外加电位对X80管线钢在轮南土壤模拟溶液中应力腐蚀行为的影响  

Effect of Applied Potential on Stress Corrosion Behavior of X80 Pipeline Steel and Its Weld Joint in a Simulated Liquor of Soil at Lunnan Area of Xinjiang

作　　者：朱丽霞 贾海东 罗金恒 李丽锋 金剑 武刚 胥聪敏[4] ZHU Lixia;JIA Haidong;LUO Jinheng;LI Lifeng;JIN Jian;WU Gang;XU Congmin(State Key Laboratory for Performance and Structure Safety of Petroleum Tubular Goods and Equipment Materials,CNPC Tubular Goods Research Institute,Xi'an 710077,China;School of Materials Science and Engineering,Xi'an University of Technology,Xi'an 710048,China;PetroChina West Pipeline Company,Urumchi 830013,China;School of Materials Science and Engineering,Xi'an Shiyou University,Xi'an 710065,China)

机构地区：[1]中国石油集团石油管工程技术研究院石油管材及装备材料服役行为与结构安全国家重点实验室,西安710077 [2]西安理工大学材料学院,西安710048 [3]中石油管道有限责任公司西部分公司,乌鲁木齐830013 [4]西安石油大学材料科学与工程学院,西安710065

出　　处：《中国腐蚀与防护学报》2020年第4期325-331,共7页Journal of Chinese Society For Corrosion and Protection

基　　金：国家重点研发计划(2016YFC0801204);陕西省自然科学基金(2019JQ-937)。

摘　　要：采用慢应变速率拉伸(SSRT)实验、SEM观察和动电位极化曲线测量等方法,研究了外加电位对X80管线钢母材及焊缝在轮南土壤模拟溶液中的应力腐蚀开裂(SCC)行为。结果表明,X80钢母材及焊缝在轮南土壤模拟溶液中均具有一定的应力腐蚀敏感性。在同一外加电位下,X80钢焊缝的SCC敏感性高于母材的;X80钢SCC敏感性及开裂机理受外加电位影响显著,在-500 mV外加阳极电位下,X80钢的SCC机理为裂尖阳极溶解-膜破裂机制,在-800 mV阴极电位以下(-850,-1000和-1500 mV),氢脆作用在SCC过程中的影响明显增强,阴极析氢反应促进了钢的氢致开裂,导致X80钢SCC敏感性显著增加。The stress corrosion cracking(SCC)behavior of X80 pipeline steel and its weld joint in a simulated liquor of soil at Lunnan area of Xinjiang was studied by means of slow strain rate tensile tests(SSRT),SEM observation and potentiodynamic polarization tests.The results showed that both the X80 pipeline steel and its weld joint have obvious SCC susceptibilities,and the mode of fracture cracking propagation is transgranular cracking(TGSCC)under different applied potentials,and the SCC susceptibility of the weld seam is higher than that of the base metal under the same applied potential.SCC susceptibility and mechanism would vary with the applied potential.At-500 mV,the SCC of both X80 steel and its weld joint may be ascribed to the synergistic action of the anodic dissolution(AD)at crack tip and the rupture of passivation film.The SCC susceptibility of X80 pipeline steel increased markedly for potentials below-800 mV(-850,-1000 and-1500 mV)due to a strong hydrogen embrittlement(HE)effect on SCC process and hydrogen induced cracking promoted by cathodic hydrogen evolution reaction.

关 键 词：X80管线钢 应力腐蚀开裂 外加电位 土壤环境 腐蚀机理 

分 类 号：TG172.4[金属学及工艺—金属表面处理]