2205双相不锈钢和304不锈钢在氢氟酸溶液中缝隙腐蚀敏感性比较  

Comparison of Crevice Corrosion Susceptibility of 2205 Duplex Stainless Steel and 304 Stainless Steel in Hydrofluoric Acid Solution

作　　者：逄旭光[1] 郭一二 迟嘉鹏 梁平[1] 史艳华[1] 赵艳[1] PANG Xuguang;GUO Yier;CHI Jiapeng;LIANG Ping;SHI Yanhua;ZHAO Yan(School of Mechanical Engineering,Liaoning Shihua University,Fushun 113001,China;Petro China Fushun Petrochemical Company,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]中国石油天然气股份有限公司抚顺石化分公司,抚顺113001

出　　处：《腐蚀科学与防护技术》2018年第4期362-368,共7页Corrosion Science and Protection Technology

基　　金：辽宁省教育厅科学研究项目(L2012127)~~

摘　　要：采用缝隙腐蚀试样,通过浸泡实验以及循环极化、电化学阻抗、电化学噪声、恒电位测试等电化学方法,研究了2205双相不锈钢(2205DSS)和304不锈钢(304SS)在5%(质量分数)氢氟酸溶液中的缝隙腐蚀行为。结果表明,两种不锈钢在氢氟酸溶液中都发生了缝隙腐蚀,但2205双相不锈钢腐蚀形成的蚀坑较浅,而304不锈钢腐蚀形成的蚀坑较深,且腐蚀面积更大。电化学测试结果表明,2205DSS的临界缝隙腐蚀电位E_(crev)和再钝化电位E_(rp)都高于304SS的,滞后环的面积也更小,钝化膜电阻和缝隙腐蚀发生时的电荷转移电阻也更大。2205DSS的白噪声水平更小,缝隙腐蚀反应更慢。同时,在相同外加电位下,2205DSS的缝隙腐蚀诱导期更长,缝隙腐蚀发生时电流更小,2205DSS的抗缝隙腐蚀能力优于304SS,这主要与两种材料表面所成钝化膜的组成和性能不同有关。The crevice corrosion behavior of 2205 duplex stainless steel（2205 DSS） and 304 stainless steel（304 SS） in 5%（mass fraction） HF solution was comparatively investigated by means of immersion test, cyclic polarization curve, electrochemical impedance spectroscopy, electrochemical noise and potentiostatic test methods. The results showed that the two stainless steels all suffered from crevice corrosion, but the corrosion pits of 2205 DSS was relatively shallow, while that of 304 SS was deeper with larger corroded area. In comparison to 304 SS, 2205 DSS exhibits higher critical potential（Ecrev） and repassivation potential for（Erp） crevice corrosion, while smaller area of hysteresis loop, as well as larger charge transfer resistance and film resistance. The white noise level of 2205 DSS was smaller, indicating a slower corrosion reaction for crevice corrosion. Meanwhile, by the same applied potential, 2205 DSS presents longer induction period for crevice corrosion and smaller crevice corrosion current density. Therefore,2205 DSS exhibited better crevice corrosion resistance than 304 SS, which was mainly related to the difference in compositions and properties of the passive films formed on the surface of the two materials.

关 键 词：2205双相不锈钢 缝隙腐蚀 氢氟酸 

分 类 号：TG172[金属学及工艺—金属表面处理]