Corrosion performance of welded stainless steels reinforcements in simulated pore solutions

This study analyses the effect of welding in corrugated bars of two austenitic stainless steels (new, low-nickel AISI 204Cu and traditional 304 types) and a duplex stainless steel (SAF 2205 type). Welds have been carried out using shielded metal arc. The effect of the welding on the corrosion behaviour has been studied using anodic polarization curves and double loop electrochemical potentiokinetic reactivation curves. Oxides formed during welding reduce the corrosion resistance of stainless steels. The surface of the reinforcements has been cleaned using pickling and sand-blasting to test their efficiency. Pickling does not completely remove oxides. Sand-blasting removes them, but forms aeration cells and deforms the surface. The efficiency of the cleaning method to assure the passivity of the reinforcements depends on the composition of the welded stainless steel and the characteristics of the environment.