8367、904L和316L奥氏体不锈钢的耐点蚀性能研究

Research on Pitting Corrosion Resistance of 8367, 904L and 316L Austenitic Stainless Steels

为了研究8367、904L和316L奥氏体不锈钢在不同环境下的的耐点蚀性能,采用电化学试验和浸泡腐蚀试验,从点蚀当量、临界点蚀温度、点蚀电位和腐蚀速率等方面进行了分析。结果表明:8367、904L和316L不锈钢在3.5%NaCl溶液中的临界点蚀温度分别为66,50,15℃;随着介质温度的升高,8367的临界点蚀点位无明显变化,904L和316L的临界点蚀点位则逐渐降低,且E_(b(8367))>E_(b(904L))>E_(b(316L));8367不锈钢在20℃和50℃的4%FeCl_(3)溶液中均具有较低的腐蚀速率,且随着温度升高,腐蚀速率无明显变化;904L和316L在20℃和50℃的4%FeCl_(3)溶液中的腐蚀速率均大于8367,且随着温度升高,904L和316L的腐蚀速率大幅度增大。

In order to study the pitting corrosion resistances of 8367, 904 L and 316 L austenitic stainless steels in different environments, electrochemical tests and immersion corrosion tests were used to analyze the pitting equivalent, critical pitting temperature, pitting potential, and corrosion rate. Results showed that the critical pitting temperatures of 8367, 904 L and 316 L stainless steels in 3.5% NaCl solution were 66 ℃, 50 ℃ and 15 ℃, respectively. The critical pitting position of 8367 had no obvious change with the increase of medium temperature, while the critical pitting positions of 904 L and 316 L stainless steels decreased gradually, leading to a result that E_(b(8367))>E_(b(904L))>E_(b(316L)). Moreover, 8367 stainless steel had low corrosion rates at 20 ℃ and 50 ℃ in 4% FeCl_(3)solution, and the corrosion rates changed little with the increase of temperature. The corrosion rates of 904 L and 316 L stainless steel in 4% FeCl_(3)solution at 20 ℃ and 50 ℃ were higher than that of 8367 stainless steel, and the corrosion rates increased greatly with the rising of temperature.