模拟深海无氧环境下阴极保护电位对X80钢应力腐蚀行为的影响  

Effect of Cathodic Protection Potential on Stress Corrosion Behavior of X80 Steel in Simulated Deep Marine Environment without Dissolved Oxygen

作　　者：袁玮[1] 黄峰[1] 张恒康 胡骞[1] 刘静[1] YUAN Wei;HUANG Feng;ZHANG Heng-kang;HU Qian;LIU Jing(The State Key Laboratory of Refractories and Metallurgy,Wuhan University of Science and Technology,Wuhan 430081,China)

机构地区：[1]武汉科技大学省部共建耐火材料与冶金国家重点实验室,湖北武汉430081

出　　处：《材料保护》2020年第11期5-12,共8页Materials Protection

摘　　要：目前关于深海环境下管线钢的应力腐蚀研究结果较少且不一致。为此,采用慢应变速率拉伸(SSRT)、电化学极化、D-S双电解池氢渗透和场发射扫描电子显微镜(FE-SEM)等方法,研究了在无氧环境下,阴极保护电位对X80管线钢在模拟海水环境中应力腐蚀行为(SCC)的影响规律及机理。结果表明:在模拟无氧海水环境下,X80管线钢的腐蚀缓慢,阴极反应以析氢为主,外加阴极保护电位抑制阳极溶解的同时加速析氢反应。在开路电位(OCP)条件下,Fe的阳极溶解和析氢均比较缓慢,从而未表现出应力腐蚀敏感性;随着外加电位的负移,析氢加速,使得表观氢浓度Capp增大,X80钢延伸率逐渐减小,在负于-1100 mV(vs SCE)以下,表现出氢致开裂型应力腐蚀敏感性。氢致塑性损失ISCC(HE)与表观氢浓度Capp呈线性增长关系。The effect rule and mechanism of the cathodic protection potential on the stress corrosion cracking(SCC)of X80 pipeline steel in simulated seawater solution without dissolved oxygen(DO)were studied by the means of slow strain rate tension(SSRT),electrochemical measurements,D-S double electrolytic cell hydrogen permeation technology and field emission scanning electron microscope(FE-SEM).Results showed that X80 pipeline steel was corroded slightly and the cathodic reaction process was mainly controlled by hydrogen evolution in the simulated seawater without DO.Under the condition of open circuit potential,the anodic dissolution and hydrogen evolution of Fe were relatively slow,and no SCC susceptibility could be observed.With the negative shifting of applied potential,the hydrogen evolution process was accelerated,causing that the apparent hydrogen solubility(Capp)increased and the elongation decreased gradually.Moreover,X80 pipeline steel had SCC susceptibility controlled by hydrogen embrittlement mechanism when the protection potential was below-1100 mV(vs SCE).The hydrogen induced ductility loss ISCC(HE)increased linearly as the Cappincreased.

关 键 词：阴极保护电位 X80管线钢 模拟无氧海水环境 SCC敏感性 

分 类 号：TG172.5[金属学及工艺—金属表面处理] TG174.41[金属学及工艺—金属学]