Experimental investigation on the corrosion behavior of G20Mn5QT cast steel and butt weld with Q345D steel

The corrosion tests of G20Mn5QT cast steel and butt weld with Q345D steel in wt 3.5% NaCl solution are conducted. The corrosion morphology of the specimens is observed by SEM. It is mainly corrosion pitting for G20Mn5QT cast steel due to the casting defect and the erosion of chloride ions. The corrosion morphology of weld zone and HAZ tends to be uniform corrosion accompanied with pitting corrosion. Welding defect and erosion of chloride ions cause pitting corrosion for weld zone and HAZ. The largest circular radius of the divided circular pits is defined as the maximum radius of the irregular pit.