Dissimilar underwater wet welding of HSLA steels

The high-strength low-alloy S460ML and S460N steels were chosen for underwater wet welding of dissimilar T-joints using covered electrodes. For improving the quality of joints, the temper bead welding (TBW) method was used. The application of TBW in pad welding conditions has been investigated earlier but the possibility of usage of this technique in welded joints was not analyzed. The main aim of the study was to check the influence of TBW on the hardness and structures of the heat-affected zone (HAZ) of dissimilar T-joints made in the underwater conditions. The experiments conducted showed that the technique used can reduce the susceptibility to cold cracking by decreasing the hardness in HAZ, which is a result of changes in its structure. The TBW technique reduced the hardness in the HAZ of the S460N steel by 40–50 HV10 and in S460ML by 80–100 HV10. It was also found that the changes in S460ML and S460N were much different, and therefore, the investigated technique can provide better results in the steel characterized by lower carbon equivalent CeIIW.