不锈钢去膜表面在氯化镁溶液中的钝化过程

采用划破电极技术,研究了不锈钢去膜表面在氯化镁溶液中的钝化过程。不锈钢在氯化镁溶液(14%,80℃)中钝化时的真实电流衰减规律为:
i(t)=C₁exp(-a₁t)+C₂exp(-a₂t)
式中第一项反映吸附膜生长速度,第二项反映氧化膜生长速度。不锈钢去膜表面在氯化镁溶液中钝化时膜成长的规律符合高电场离子传导的膜生长机理。

Kinetics of Passivation of Stainless Steel in Chloride Solution

When freshly generated stainless steel surface is passivating in the chloride solution,the true current decay law,i (t),that is independent of the methods of mechanically removing the oxide film on the metal surface and of parameters selected in experiment,follows
i (t)=C₁exp(-a₁t) + C₂exp(-a₂t)
The first term in this equation is associated mainly with the growth of MeOH adsorbed film,the second term is related to the growth of oxide film. At potentials above a critical potential that is well below the pitting potential measured from the surface covered by oxide film,corrosion pit would occur on the freshly generated surface. The film growth on the stainless steel in MgCl₂ solution follows the high field ion conduction mechanism.