Fatigue crack growth rate in underwater wet welds: out of water evaluation

The characteristics of fatigue crack propagation in welds produced in conventional conditions (welds made out of water) and in underwater repair welding conditions (underwater wet welding) were evaluated out of water. The fatigue crack growth rates da/dN showed considerable dependence on pore density and distribution, factors that vary significantly with the welding process and the environment. Variations in the fatigue crack propagation rate were correlated with analysis of the fracture surface in the zone of stable crack propagation. The results of this study show that the underwater wet welding procedure produces weld metal resistant to fatigue, which is suitable for use at low applied stresses in offshore structures.