柠檬酸钝化9Cr1Mo钢在海洋大气环境中的耐蚀性

Corrosion Resistance of 9Cr1Mo Steel with Citric Acid Passivation in Marine Atmosphere Environment

为了提高9Cr1Mo钢在海洋大气环境中的耐蚀性,采用柠檬酸和柠檬酸-氢氧化物复合钝化工艺对9Cr1Mo钢进行表面钝化处理,研究了两种钝化处理对其耐蚀性的影响,分析了柠檬酸钝化处理提升9Cr1Mo钢耐海洋大气腐蚀性能的原因。结果表明:未钝化处理的9Cr1Mo钢在模拟和实际海洋大气环境中均发生严重腐蚀;两种钝化处理后9Cr1Mo钢表面均形成了保护性钝化膜,确保9Cr1Mo钢在海洋大气环境中腐蚀78d内不发生明显腐蚀,显著提高了9Cr1Mo钢耐海洋大气腐蚀性能;采用柠檬酸和柠檬酸-氢氧化物复合钝化工艺可以提高钝化膜中Cr_(2)O_(3)、Cr(OH)_(3)含量,且氧化物含量显著高于氢氧化物,钝化膜的稳定性和耐蚀性增强。

In order to improve the corrosion resistance of 9Cr1Mo steel in marine atmospheric environment, the citric acid passivation and citric acid-hydroxide composite passivation were selected to passivate the 9Cr1Mo steel. Their effects on the corrosion performance of 9Cr1Mo steel were investigated, and the reasons for the enhanced corrosion resistance of 9Cr1Mo steel treated by citric acid passivation treatments were analyzed. The results showed that the 9Cr1Mo steel without passivation treatment underwent serious corrosion in both simulated and real marine atmospheric environments. The protective passive film was able to be formed on the surface of 9Cr1Mo steel by two kinds of passivation treatments, which ensured that the passivated 9Cr1Mo steel did not be corroded within 78 days in the real marine atmosphere. The corrosion resistance of 9Cr1Mo steel in marine atmospheric was remarkably enhanced by passivation treatments. Citric acid and citric acid-hydroxide composite passivation process could increase the content of Cr_(2)O_(3), Cr(OH)_(3) and oxides in passivation film, and those content was significantly higher than that of hydroxide, thereby improving the stability and corrosion resistance of the passive film.