CORROSION OF WELDED STEEL IN CHLORIDE ENVIRONMENT UNDER ACCELERATED CONDITIONS

Abstract

The present study has been conducted to observe the corrosion behaviour of mild steel processed by MMAW of as welded and post weld heat treated specimens exposed to 3.5 M Nacl solution under accelerated conditions with regard to electro potential values of weld metal, heat affected -zone and base metal. The test was conducted for a exposure period of 20 days. In the study Rutile and Basic electrodes are used for welding mild steel plates. The electro potential values of weld metal, heat affected zone, ;Base . metal are calculated and they are interpreted to corrosion rates. The electro potential values are measured with reference to saturated ç1omel electrode. The electro potential - values of weld metal are anodic as compared to heat affected zone and hence weld metal corroded more than heat affected zone. In the same way heat affected zone is anodic to base metal and hence heat affected zone corroded more than base metal. The corrosion rate of post weld heat treated specimens are less as compared to as welded specimens due to the homogenity of microstructure in post weld heat treated specimens