445J2超纯铁素体不锈钢的点腐蚀行为研究

Research on Pitting Corrosion Behavior of 445J2 Ultra-pure Ferritic Stainless Steel

采用电化学测试方法研究了445J2超纯铁素体不锈钢和316L奥氏体不锈钢在不同温度、浓度Cl^(-)环境下的点腐蚀行为,通过恒电位极化测试方法研究了两种不锈钢的临界点蚀温度,采用扫描电镜(SEM)分析其点蚀形貌。结果表明:445J2不锈钢临界点蚀温度为48℃,高于316L的20℃,前者耐点蚀性能优于316L不锈钢的;随着环境温度的升高,两种钢的点腐蚀行为明显加剧。

The pitting corrosion behavior of 445J2 ultra-pure ferritic stainless steel and 316L austenitic stainless steel at different temperatures and different concentrations of Cl^(-) was studied by electrochemical test methods. The critical pitting temperature of the two stainless steels was studied by constant potential polarization test method. The scanning electron microscope(SEM) was used to analyze the pitting morphology. The results show that the critical pitting temperature of 445J2 stainless steel is 48℃, which is higher than 20℃ of 316L. The pitting corrosion resistance of the former is better than that of 316L stainless steel. The pitting corrosion behavior of the two kinds of steels are obviously intensified with the increase of ambient temperature.