Effects of inhomogeneous elastic stress on corrosion behaviour of Q235 steel in 3.5% NaCl solution using a novel multi-channel electrode technique

• Inhomogeneous elastic stress can contribute to localized corrosion of Q235 steel.
• A novel multi-channel electrode system was developed.
• Distribution and intensity of anodic and cathodic areas in corrosion was assessed.
• Corrosion products have a significant influence on localized corrosion behaviour.

In-situ corrosion characterization of Q235 steel under inhomogeneous elastic stress in 3.5% NaCl solution was investigated by zero resistance ammeter and electrochemical noise techniques combined with a newly developed multi-channel working electrode and reference electrode system. The galvanic corrosion, resulted from the so-called stress cell with the higher stress locations as anodes relative to the low stress locations, could be induced by the applied inhomogeneous elastic stress. The distribution and intensity of anodic and cathodic areas in galvanic corrosion were shown to be a function of corrosion time. The effect of corrosion products on the corrosion behaviour was also discussed.