This study is mainly concerned with the influence of the changes in the microstructure on corrosion rates of underwater steel welds. Chemical analysis and microstructural studies were performed for both the weld joints, which were made in underwater and open-air conditions. The salt water and the welding electrode wires used in this study were also chemically analyzed.
It has been found that lower corrosion rates resulted due to occurrence of dendritic, bainitic, and martensitic structures in salt water for underwater welds compared to open-air welds, which were made under the same set of welding parameters. It was also concluded that low corrosion rate occurred because of high molybdenum content and low magnitude of residual surface stresses that developed in underwater welds.
