Study of techniques for improving wet underwater welds

Structures used in the offshore sector, such as ships and platforms, are designed to withstand a wide variety of stresses while remaining intact and, above all, safe. In order to meet these needs for longer, the maintenance carried out on them must maintain the required mechanical properties. Wet welding with coated electrodes (SMER) has been widely used due to its low cost compared to other processes, its versatility in work and the fact that it already achieves good quality results. One of the main problems is the loss of ductility in heated regions adjacent to the weld or the thermally affected zone (HAZ), because due to the rapid cooling inherent in the wet process, a microstructure of high hardness and low toughness is generated. This work will study the techniques of "grinding the reinforcement at each pass" and "reversing the welding direction" in order to improve hardness in multipass wet welds. This work is a master's thesis presented on 11/2017 at UFMG. Thanks to LRSS, PPGMEC, CAPES and PETROBRAS.