Influence of weld size on fatigue crack growth characteristics of flux cored arc welded cruciform joints

The influence of weld size (L/Tp) on fatigue crack growth characteristics of flux cored arc welded (FCAW) cruciform joints, containing lack of penetration (LOP) defect, has been studied. Quenched and tempered (Q&T) steel of ASTM 517 ‘F’ grade has been used as the base material. Fatigue crack growth experiments were carried out in a vertical pulsar under constant amplitude loading (R=0). Crack growth rates were found to be relatively lower in the larger welds fabricated by the multipass technique. The number of weld passes involved in the fabrication of joints is mainly attributed to the changes in microstructure of weld metals, which in turn caused the differences in fatigue crack growth characteristics.