Interaction between austein-ferrite phases on passive performance of 2205 duplex stainless steel

The passive behavior of 2205 duplex stainless steel (DSS) and its individual phases (alpha-phase, gamma-phase) in neutral 3.5% NaCl solution was investigated by various electrochemical methods. The results indicated that galvanic effect between alpha and gamma phases cannot deteriorate local corrosion, but favors the enhancement of the passive film. Under the galvanic effect, the diffusion of the dissolved passive cations would be promoted in a short distance between alpha and gamma zones, leading to modifications of the chemical composition and semiconductive property of the passive film and therefore the enhancement of the corrosion resistance of DSS 2205. (C) 2018 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.