关键词: 电偶法, 不锈钢钝化膜, 醛化液, 自钝化

Abstract: Properties of self_passivation for the anodic passive film of 1Cr18Ni9Ti and the firsthand passive film of SUS 36 stainless steel in vinylon aldehyde solution(H 2SO 4(240 g/L)+Na 2SO 4(70 g/L)+HCHO(25 g/L)+[Fe 3+ ](35.4 mg/L)+[Cl -](240 mg/L) at 70 ℃ were studied by galvanostatic and potentiostatic polarization mesurements. The effects of compponents of vinylon aldehyde solution, i.e. Fe 3+ and Cl -, on the passivation behaviours of stainless steel have also been investigated. The experimental results showed there is a conversion zone of the active/passive state if the area ratio of active/passive state on these stainless steel attained to a critical value, while the locally damaged passive film by mechinery process could be repassivated by polarization of active_passive couple in a certain medium and so that corrosion may be prevented.

Key words: Galvanic method, Passive film of stainless steel, Vinylon aldehyde solution, Self_passivation