含铬铸钢在混合盐中腐蚀行为的研究

对不同成分的含铬铸钢进行了与电化学试验，利用恒电位仪、扫描电镜和ＸＰＳ手段，研究了试验材料在混合盐（０．１％ＮａＣｌ＋０．５％Ｎ２ＳＯ４＋Ｈ２ＳＯ４，ｐＨ＝６）中的抗蚀行为，试验表明铬含量对铸钢耐蚀性有显著的影响。当含理达到８％以上，铸钢表面形成了氧化膜。氧化膜富氧、富铬而贫铁，膜中的Ｃｒ／Ｆｅ比远大于基体中的值；膜的表层含有铬与铁的氢氧化物和氧化物。这种氧化对含铬约８％的铸钢起到了保护作用。

CORROSION BEHAVIORS OF THE CHROMIUM STEELS IN THE MIXED SALT SOLUTION

The immersion and electrochemical tests have been performed on the chromium steels in the mixed salt solution (0.1%NaCl+0.5%Na_2O_4+H_2SO_4, pH=6).The corrosion behaviors of the steels have been investigated using the potentiostat, SEM and XPS. The tests show that the chromium content has significant effect on the corrosive resistance of the alloys.Theoxide film can form on the surface of the steel if chromium content increases to 8%. The passive film is rich in oxygen and chromium, and depleted of iron;The film, which is composed of complex oxyhydroxides, refrains from corrosion of steels.