载波钝化及其后处理对不锈钢钝化膜组成及稳定性的影响

EFFECTS OF A. V. PASSIVATION AND POST-TREATMENT ON THE COMPOSITION AND STABILITY OF PASSIVE FILM ON STAINLESS STEELS

一、前言钝化是不锈钢得以广泛应用的前提之一,人们不断地探索提高钝化膜稳定性的新途径。一些学者认为,交变电场对钝化膜具有破坏作用。这种看法有一定的片面性。我们曾发现,在直流钝化电位基础上叠加一定频率,幅值和波形的交变电场对不锈钢进行载波钝化,所得到的载波钝化膜再经适当的后处理,其稳定性远远优于相同条件下得到的直流钝化膜,其中最佳的载波钝化及后处理条件可使不锈钢钝化膜稳定性提高5个数量级左右。本工作通过AES等分析手段,从钝化膜组成变化角度探讨载波钝化及后处理提高钝化膜稳定性的原因。

An investigation of the effects of A. V. modulated passivation and post-treatment on the composition and stability of passive film on 302 and 316 s.s. was carried out by means of AES analysis,ellipsometry and electrochemical measurements. The experimental results showed that the concentration and profile distribution of elements in the passive film was changed by A. V. passivation, the relative concentrations of O and Cr and the Fe^(3+)/Fe^(2+) in the A. V. passivated film were higher than the corresponding ones in the D.V. passivated film. During the process of post-treatment molybdenun-containing ions were adsorbed onto the surface of passive film. The causes of increase of the stability of passive film by A.V. passivation and post-treatment were discussed.