Wet/Electrochemical Corrosion

• Takes place under moist conditions through formation of galvanic cells when the conducting liquid is in contact with a metal or when two dissimilar metals are immersed or partially dipped in a solution
• 1. Oxidation occurs at anode generating metallic ion, ie corrosion occurs at anode
• 2. Reduction takes place at cathode. Here, dissolved components like O2 or H+ in conducting medium accepts the electron and forms non-metallic ions like OH-
• 3. Diffusion of metallic and non-metallic ions towards each other through the conducting solution and formation of corrosion product somewhere between anodic and cathodic areas
• 4. separate anodic and cathodic components are formed due to deposition of corrosion product between which current flows through conducting medium