S32750超级双相不锈钢在低温模拟海水中的腐蚀行为  

Corrosion Behavior of S32750 Super Duplex Stainless Steel in Simulated Seawater at Low Temperature

作　　者：侯冠宇 刘润青 梁平[1] 任建民[1] 史艳华[1] 赵艳[1] HOU Guan- yu;LIU Run- qing;LIANG Ping;REN Jian- min;SHI Yan- hua;ZHAO Yan(School of Mechanical Engineering, Liaoning Shihua University, Fushun 113001, China)

机构地区：[1]辽宁石油化工大学机械工程学院,辽宁抚顺113001

出　　处：《材料保护》2018年第5期30-33,38,共5页Materials Protection

基　　金：辽宁省教育厅2012年科学研究一般项目(L2012127)资助

摘　　要：为了考察S32750超级双相不锈钢(SDSS)在低温海水中的腐蚀性能,通过浸泡试验、动电位极化和电化学阻抗等方法,研究了S32750 SDSS和316L不锈钢(316L SS)在5℃的模拟海水(质量分数为3.5%Na Cl)中的腐蚀行为,采用Mott-Schottky曲线对低温下钝化膜的半导体性质进行了分析,并通过金相显微镜观察了两者腐蚀后的表面形貌。结果表明:在低温海水中,S32750 SDSS比316L SS表现出了更低的腐蚀速率,且S32750 SDSS表面腐蚀凹坑的数量较少;2种不锈钢均能形成稳定的钝化膜,且S32750 SDSS比316L SS展现出更大的钝化区间以及更高的点蚀电位、钝化膜电阻和电荷转移电阻,这主要与S32750 SDSS表面钝化膜更加致密、缺陷数量更少等因素有关。The corrosion behaviors of S32750 super duplex stainless steel （SDSS） and 316L stainless steel （SS） in simulated seawater envi- ronment （3.5% NaC1） at 5℃ were investigated by immersion test, dynamic polarization and electrochemical impedance spectroscopy （EIS）. Mott - Schottky curves were used to study the semiconductor characters of the passive film at low temperature, and the morphology after corrosion was observed by metallographic microscope. Results showed that the S32750 SDSS presented lower corrosion rate than 316 SS, and the number of corrosion pits on the surface of S32750 SDSS was less than that of 316L SS. The stable passive film could be formed on both kinds of stainless steels in simulated seawater. Furthermore, the S32750 SDSS exhibited wider passivation range, higher pitting potential, and greater passivation corrosion and charge transfer resistance than 316L SS, which related to denser passivation film and less defects on S32750 SDSS.

关 键 词：S32750超级双相不锈钢 316L不锈钢 低温 模拟海水 腐蚀性 

分 类 号：TG172.5[金属学及工艺—金属表面处理]