温度对904L不锈钢耐点蚀性能的影响

Effect of Temperature on Pitting Corrosion Behavior of the 904L Stainless Steel

采用FeCl3溶液浸泡试验、动电位极化、电化学阻抗谱及体式显微镜研究了904L超级奥氏体不锈钢在不同温度下的点蚀行为。结果表明:溶液温度为25℃时,904L不锈钢具有优异的耐点蚀性能,随着溶液温度的升高,其耐点蚀性能下降,在65℃FeCl3溶液中基体表面产生严重的点蚀坑。在不同温度模拟海水溶液中的电化学测试结果同样表明:随着试验温度的提高,自腐蚀电流密度增大,点蚀电位下降,点蚀敏感性提高;EIS均为单一的容抗弧,温度升高,容抗弧半径减小,材料腐蚀速率增大,耐蚀性降低。

The pitting corrosion behavior of 904L super austenitic stainless steel at different temperatures was studied by pitting test of FeC13 solution, potentiodynamic polarization and stereo microscopy. The results showed that 904L stainless steel had excellent pitting corrosion resistance at room temperature, with the increase of test temperature, the pitting corrosion resistance of 904L stainless steel decreased. In the FeC13 solution at 65 ℃, serious pitting corrosion holes were found on the surface of tested 904L matrix. The results of the electrochemical test also showed that as the temperature increased, the pitting potential decreased, EIS presented as single capacitive arc, and the radius of the arc also decreased, which indicated the corrosion rate increased and the corrosion resistance decreased.