摘要
采用开路电位、电化学阻抗谱（EIS）、Mott-Schottky曲线和浸泡腐蚀实验研究了2507双相不锈钢在含不同浓度（0,0.001和0.01 mol·L-1）NaHSO3模拟海水中的腐蚀行为.研究表明：开路电位随NaHSO3浓度的增加而负移,腐蚀倾向增大;电荷转移电阻Rt随浓度的增加而减小,耐蚀性降低;2507不锈钢的腐蚀形态为局部腐蚀,点蚀程度随浓度升高有所加剧,腐蚀速率随浓度的增加而增大;Mott-Schottky曲线和成膜后电化学阻抗谱测试表明,NaHSO3的加入增加了2507不锈钢表面钝化膜的点缺陷浓度,降低了钝化膜的稳定性,电荷转移阻力减小,腐蚀更容易发生.这可能归因于NaHSO3的加入增加了模拟海水的酸度,并随NaHSO3浓度的增加促进了不锈钢表面钝化膜的破坏.
The corrosion behavior of 2507 duplex stainless steel in simulated seawater containing different concentrations of NaHSO3 solution was investigated using open circuit potential,electrochemical impedance spectroscopy（ EIS）,Mott-Schottky curves,and an immersion corrosion test. The results depict that the open circuit potential shifts negatively with an increase in the concentration of NaHSO3,whereas the corrosion tendency of the steel increases. The charge transfer resistance（ Rt） decreases with the increased concentration of NaHSO3,which suggests that the corrosion resistance is reduced. The corroded stainless steel exhibits localized pitting corrosion. Further,the degree of corrosion as well as the corrosion rate increases with an increase in the concentration of NaHSO3. The results that are obtained using the Mott-Schottky curves and EIS test depict that the addition of NaHSO3 increases the concentration of point defects on the passive surface film of 2507 stainless steel,reducing its stability and decreasing its charge transfer resistance,resulting in an increased probability of corrosion. This may be caused due to the fact that the addition of NaHSO3 increases the acidity of the solution,which accelerates the damage that is caused to the passive film on the stainless steel.
作者
朱敏
朱涛
陈明
郭绍义
袁永锋
俞高红
聂轮
ZHU Min;ZHU Tao;CHEN Ming;GUO Shao-yi;YUAN Yong-feng;YU Gao-hong;NIE Lun(School of Mechanical Engineering and Automation, Zhejiang Sci-Tech University, Hangzhou 310018, China;Zhejiang Meili High Technology Co. , Ltd. , Xinchang 312500, China)
出处
《工程科学学报》
EI
CSCD
北大核心
2018年第5期587-593,共7页
Chinese Journal of Engineering
基金
国家自然科学基金资助项目(51501164)
浙江省自然科学基金资助项目(LY18E010004)
中国博士后科学基金资助项目(2017M621974)
关键词
2507不锈钢
腐蚀行为
钝化膜
点蚀
NAHSO3
2507 stainless steel
corrosion behavior
passive film
pitting corrosion
sodium hydrogen sulfite
