铬含量对低合金钢耐氯离子腐蚀的影响规律和机制

Effect of Cr Content on Corrosion Law and Mechanism of Chloride-Resistance for Low Alloy Steel

采用浸泡腐蚀试验、X射线衍射(XRD)分析、扫描显微镜(SEM)和电化学试验等方法,研究了不同铬含量的油轮钢在模拟原油货油舱环境中的腐蚀规律和机理。结果表明:随着铬含量的增加,油轮钢耐蚀性先增加后下降;当铬的质量分数为0.06%和0.12%时,油轮钢的耐蚀性最好。铬提高油轮钢耐蚀性的作用机制是促进钢铁表面产生致密的腐蚀产物从而减缓腐蚀。

The corrosion law of tanker steels with different Cr content in a simulated corrosion environment around cargo oil tank was investigated by soaking corrosion test, XRD analysis, scanning electron microscopy （SEM） and electrochemical test. The results indicated that the corrosion resistance of developed tanker steels was increased first and then decreased with increasing Cr content; the corrosion resistance of oil tanker steels was the best when the mass fraction of Cr was 0. 06% and 0. 012%. The mechanism by which Cr improves the corrosion resistance of tanker steel is to promote the generation of compact corrosion products on the steel surface and thus to reduce corrosion.