Fatigue Crack Growth Rate in Underwater Wet Welds: Out of Water Evaluation

Abstract

Fatigue cracks propagation characteristics of welds produced in conventional conditions (welds made out of water) and underwater condition (Underwater wet welding) were evaluated out of the water. The growth rates of fatigue crack da/dN showed a significant dependency on the density and distribution of pores, factors which may vary significantly with the welding process and environment. Variations in the propagation speed of the fatigue crack were correlated with the analysis of the fracture surface on the stable propagation crack zone. The results of this study showed that the underwater wet welding procedure produces weld metal resistant to fatigue that is suitable to be used at low stresses applied to offshore structures.

Key-words:
Crack growth; Fatigue; Underwater wet welding