划伤方法研究应力作用下硫代硫酸根对800合金再钝化动力学的影响  

Repassivation Process on Stressed Alloy 800 in Simulated Crevice Chemistry Containing Thiosulfate

作　　者：祝钰 王泽清 孙颖昊 林芳旭 夏大海 宋诗哲 王俭秋[2] 张志明[2] ZHU Yu1, WANG Zeqing1, SUN Yinghao1, LIN Fangxu1, XIA Dahai1,2, SONG Shizhe1,2, WANG Jianqiu2, ZHANG Zhiming2(1. Tianjin Key Laboratory of Composite and Functional Materials, School of Material Science and Engineering, Tianjin University, Tianjin 300354, China; 2. Key Laboratory of Nuclear Materials and Safety Assessment, Institute of Metal Research, Chinese Academy of Sciences, Shenyang 110016, China)

机构地区：[1]天津大学材料科学与工程学院天津市材料复合与功能化重点实验室,天津300354 [2]中国科学院金属研究所中国科学院核用材料与安全评价重点实验室,沈阳110016

出　　处：《腐蚀科学与防护技术》2018年第5期503-507,共5页Corrosion Science and Protection Technology

基　　金：国家自然科学基金(51701140);2016年天津大学大学生创新创业训练计划(201610056389);中国科学院核用材料与安全评价重点实验室开放课题(2018NMSAKF01)~~

摘　　要：采用划伤方法研究应力作用下硫代硫酸根对800合金再钝化动力学的影响机理,采用C形环对试样进行应力加载。结果表明,划伤过程的最大电流与再钝化电流随电极电位的升高而升高,随着电位升高划伤部位的阳极溶解过程加快。与应力加载前对比,试样加载后划伤过程的最大电流与再钝化电流均增加,表明应力使金属的阳极溶解速度变快,同时使再钝化过程变难。硫代硫酸根可与应力协同阻止再钝化过程,这主要是由于硫代硫酸根的吸附与电化学还原成吸附硫,进而加快金属的溶解所致。The repassivation kinetics of stressed Alloy 800 in simulated crevice chemistries containing thiosulfate is studied by scratch test, while the stress is exerted by a C-ring sample. Results indicate that, as the potential moves to anodic directions, the maximum current and repassivation current increase, which reveals that the anodic dissolution rate increases. Compared to the unstressed sample, the maximum current and repassivation current of the stressed sample are higher, indicating an increased anodic dissolution rate and a retarded repasivation process. The retard effect of thiosulfate on the repassivation of the alloy may be ascribed to that thiosulfate is adsorbed and then electrochemically reduced to elemental sulfur on the bare metal surface, which subsequently enhance the anodic dissolution.

关 键 词：800合金 划伤 再钝化 蒸汽发生器 缝隙水化学 应力 

分 类 号：TG172[金属学及工艺—金属表面处理]