超级奥氏体不锈钢的热腐蚀行为及机理研究  

Corrosion Behavior of Three Super Austenitic Stainless Steels in a Molten Salts Mixture at 650-750 ℃

作　　者：韩瑞珠 贾建文 李阳[2] 张威[2] 徐芳泓[2] 侯利锋[1] 卫英慧[1] HAN Ruizhu;JIA Jianwen;LI Yang;ZHANG Wei;XU Fanghong;HOU Lifeng;WEI Yinghui(Shanxi Province Metal Material Corrosion and Protection Engineering Technology Research Center,College of Materials Science and Engineering,Taiyuan University of Technology,Taiyuan 030024,China;State Key Laboratory of Advanced Stainless Steel,Taiyuan Iron and Steel(Group)Co.Ltd.,Taiyuan 030003,China)

机构地区：[1]太原理工大学材料科学与工程学院山西省金属材料腐蚀与防护工程技术研究中心,太原030024 [2]太原钢铁(集团)有限公司先进不锈钢材料国家重点实验室,太原030003

出　　处：《中国腐蚀与防护学报》2023年第2期421-427,共7页Journal of Chinese Society For Corrosion and Protection

摘　　要：研究了254SMo、904L和317L超级奥氏体不锈钢在650、700和750℃下30%Na_(2)SO_(4)+30%K_(2)SO_(4)+20%NaCl+20%KCl混合熔盐中的热腐蚀行为。通过腐蚀动力学以及腐蚀产物成分和形貌分析,探究了3种不锈钢在熔融混合盐中的高温腐蚀机理。结果表明,3种不锈钢在不同温度下均表现为失重,耐蚀性顺序为254SMo>904L>317L不锈钢;熔融的氯盐加速腐蚀,主要遵循“电化学腐蚀+氯活性腐蚀”腐蚀机制,硫酸盐通过“碱性助溶”机制溶解和破坏腐蚀层,从而造成严重的内部和晶间腐蚀;在两种腐蚀机制中,以氯腐蚀为主,硫腐蚀为辅;提高Mo和Ni含量可以在一定程度上改善奥氏体不锈钢的耐高温腐蚀性。The high temperature corrosion properties of three super austenitic stainless steels 254SMo, 904L and 317L, were studied in a molten salts mixture of 30%Na_(2)SO_(4)+30%K2SO_(4)+20%NaCl+20%KCl at 650, 700 and 750 ℃ for 50 h, respectively. By virtue of examination of the corrosion kinetics,composition and morphology of corrosion products, the high-temperature corrosion mechanism of three kinds of austenitic stainless steels in the molten salts’ mixture was explored. The results show that all the three steels exhibit mass loss at different temperatures, and the order of corrosion resistance of the three steels can be ranked as follows: 254SMo>904L>317L. Molten chloride salts would accelerate the corrosion of steels and the corrosion mechanism of which may be ascribed to electrochemical corrosion and chlorine active corrosion. Sulfates dissolve and destroy the corrosion products by means of alkaline codissolution and thus result in serious internal and intergranular corrosion. Although all three steels are subjected simultaneously to both sulfate salt and chloride salt induced corrosion, the chloride salts are predominant in terms of the severity of corrosion. However, the addition of Mo and Ni can improve the high temperature corrosion resistance of austenitic stainless steel to a certain extent.

关 键 词：奥氏体不锈钢 热腐蚀 腐蚀动力学 

分 类 号：TG174[金属学及工艺—金属表面处理]