海水中极化电位对X70钢氢脆敏感性的影响  

Effects of polarized potentials on the susceptibility to hydrogen embrittlement of X70 steel in seawater

作　　者：张林[1] 杜敏[1] 刘吉飞 李妍[2] 刘培林[2] 

机构地区：[1]中国海洋大学化学化工学院,山东青岛266100 [2]海洋石油工程股份有限公司设计公司,天津300451

出　　处：《材料科学与工艺》2011年第5期96-101,共6页Materials Science and Technology

基　　金：国家重大专项资助项目(2008ZX05056-03-05)

摘　　要：为探索X70钢最大阴极保护电位,采用电化学测试和慢应变速率实验(SSRT)并结合断口扫描电镜观察,研究了低温低溶解氧和常温海水中阴极极化电位对X70钢氢脆敏感性的影响.结果表明:相对常温海水,X70钢在低温低溶解氧海水中的析氢电位正移;随阴极极化电位的负移,X70钢的最大抗拉强度、屈服强度增加且氢脆敏感性增加;在低温低溶解氧海水中,当极化电位负于-1050 mV时(相对于饱和甘汞电极电位),断口出现准解理断裂特征形貌;相同电位下,X70钢在低温低溶解氧海水中的氢脆敏感性低于常温海水.To explore the maximum protection potential for X70 steel in seawater,the susceptibility of X70 steel to hydrogen embitterment was investigated in low temperature and low dissolved oxygen seawater and in normal temperature seawater by means of slow strain rate test,electrochemical test and SEM observation of fracture surfaces.The results show that the hydrogen evolution potential of X70 steel in low temperature and low dissolved oxygen seawater decreases compared with the normal temperature seawater.The maximum tensile strength,yield strength and the susceptibility to hydrogen embitterment increase with shifting potential in the negative direction.When the polarization potentials are negative to-1050 mV in low temperature and low dissolved oxygen seawater,the fracture surfaces exhibit quasi-cleavage fracture.At the same potential,the susceptibility to hydrogen embitterment of X70 steel in low temperature and low dissolved oxygen seawater is lower than that in normal temperature seawater.

关 键 词：氢脆 阴极极化 低温低溶解氧 慢应变拉伸 X70钢 

分 类 号：TG174.41[金属学及工艺—金属表面处理]