304不锈钢板的钝化处理及耐蚀性

Passivati on Treatment and Corrosi on Resistance o f 304 Stainless Steel Plate

使用硝酸和重铬酸钾的混合液对304不锈钢板进行了钝化处理。研究发现:不锈钢表面钝化过程伴随着钝化膜的生成和溶解。与304不锈钢板相比,钝化膜中铬和氧的质量分数提高。钝化膜主要由金属氧化物和金属氢氧化物构成。经过钝化处理后,304不锈钢板的自腐蚀电位正移,自腐蚀电流密度降低,膜电阻升高,耐蚀性增强。

304 stainless steel plate was passivated in a mixture of nitric acid and potassium dichromate. It was found that the passivation of stainless steel was accompanied by the formation and dissolution of passivation film. Compared with 304 stainless steel plate, the mass fraction of chromium and oxygen in the passivation film were increased obviously. The passivation film was composed of metal oxide and metal hydroxide. After passivation treatment, the self-corrosion potential of 304 stainless steel moved towards the positive direction, the self-corrosion current density was decreased and the film resistance was increased, thus resulting in the improvement of corrosionresistance.