脱硝剂浓度对S2205不锈钢耐蚀性及其临界点蚀温度的影响  

Effect of Denitration Agent Concentration on Corrosion Resistance and Critical Pitting Temperature of S2205 Stainless Steel

作　　者：崔浩燃 梁平[1] 史艳华[1] 杨众魁 韩利 CUI Haoran;LIANG Ping;SHI Yanhua;YANG Zhongkui;HAN Li(School of Mechanical Engineering,Liaoning Petrochemical University,Fushun 113001,China;Far East Shaie Oil Refinery Co.,Ltd,Fushun 113001,China)

机构地区：[1]辽宁石油化工大学机械工程学院,抚顺113001 [2]远东页岩炼化有限责任公司,抚顺113001

出　　处：《中国腐蚀与防护学报》2021年第4期529-534,共6页Journal of Chinese Society For Corrosion and Protection

基　　金：辽宁省大学生创新创业训练项目(201910148057)。

摘　　要：采用动电位极化曲线和电化学阻抗测试研究脱硝剂NaClO_(2)浓度对S2205不锈钢耐蚀性能的影响,采用Mott-Schottky曲线测试钝化膜的性能,采用恒电位极化法测定不同浓度下的临界点蚀温度(CPT)。结果表明:随着浓度的增加耐蚀性先减小后增大;在0.4~0.6 V电位区间钝化膜内层p型半导体中难溶性的Cr^(3+)氧化物转变为可溶性Cr^(6+)氧化物,钝化膜稳定性下降,6%浓度时载流子密度最大,耐蚀性最差;浓度为3%,6%和9%对应的CPT分别为65.2,57.4和62.5℃。The effect of denitration agent(NaClO_(2)) concentration on the corrosion resistance of S2205 stainless steel in denitration solutions was studied by means of potentiodynamic polarization curve, electrochemical impedance and Mott-Schottky curve measurements. Meanwhile, the variation of critical pitting temperature(CPT) with the NaClO_(2) concentration was measured by potentiostatic polarization method. The results show that as the NaClO_(2) concentration increases, the corrosion resistance of the steel decreases first and then increases. In the potential range of 0.4~0.6 V, the insoluble Cr^(3+) oxide in the passivation film of p-type semiconducting is transformed into soluble Cr^(6+) oxide, as a result, which degrade the stability of the passivation film. The carrier density is the largest and the relevant corrosion resistance is the worst for the passivation film formed in the solution with 6%NaClO_(2). The CPTs corresponding to the solutions containing 3%, 6%, and 9% NaClO_(2) were 65.2, 57.4 and 62.5 ℃, respectively.

关 键 词：S2205不锈钢 脱硝剂 电化学测试 临界点蚀温度 

分 类 号：TG172.4[金属学及工艺—金属表面处理]