S32750超级双相不锈钢在NaCl溶液中的临界点蚀温度及电化学腐蚀机理  

Electrochemical Corrosion and Critical Pitting Temperature of S32750 Super Duplex Stainless Steel in NaCl Solution

作　　者：何进[1,2] 晏敏胜 杨丽景 Masoumeh Moradi 宋振纶 蒋业华[1] 

机构地区：[1]昆明理工大学材料科学与工程学院,昆明650093 [2]中国科学院宁波材料技术与工程研究所中国科学院海洋新材料与应用技术重点实验室,宁波315201

出　　处：《中国腐蚀与防护学报》2015年第2期106-112,共7页Journal of Chinese Society For Corrosion and Protection

基　　金：国家自然科学基金项目(51301193);中国博士后基金面上项目(2013M540503)资助

摘　　要：采用电化学测试研究了S32750超级双相不锈钢在3.5%Na Cl溶液中的临界点蚀温度(CPT)及电化学腐蚀机理,结合试样点蚀前后的形貌变化,得出S32750不锈钢的临界点蚀温度为71℃。在低于临界点蚀温度时,不锈钢表面能形成稳定的钝化膜;高于临界点蚀温度时,由于Cl-的活性增加及钝化膜的溶解,不锈钢表面产生点蚀现象,且温度越高,点蚀越剧烈。构建了双相不锈钢S32750临界点蚀温度前后的电化学腐蚀模型。The electrochemical corrosion behavior and critical pitting temperature(CPT) of S32750 super duplex stainless steel in 3.5%Na Cl solution were investigated by electrochemical techniques.The morphologies of the steel before after pitting corrosion were observed by scanning electron microscope. The CPT of the S32750 steel was identified as 71 ℃. A passive film could form on the steel surface when the solution temperature was below the CPT. While, when the solution temperature was above the CPT, pitting corrosion occurred on the steel surface as the result of the breakdown of the passive film due to the increase of the Cl-activity. Pitting corrosion became more serious with the increasing temperature. Moreover, the corrosion models of the steel below and above the CPT were sketched respectively.

关 键 词：双相不锈钢 临界点蚀温度 钝化 腐蚀 

分 类 号：TG142.71[一般工业技术—材料科学与工程] TG172[金属学及工艺—金属材料]