Effect of vibratory weld conditioning on welded valve properties

The approach to improve the quality of full welded valve by the application of vibratory weld conditioning (VWC) was investigated in this paper. The effect of VWC on the welded joint properties was studied. Cylinders with different thicknesses were welded by submerged arc welding (SAW). The experiment results show that the vibration applied during welding generally reduces the residual deformation and stress. The yield strength, as well as the tensile strength, does not change distinctively in vibratory SAW (V-SAW) when compared with that in normal SAW (N-SAW). The bend property has been improved in V-SAW. Fracture test was carried out using single edge notch bend (SENB) specimens. The fracture surfaces of failed weld metal (WM) specimens are characterized by dimple-like structures. The depth and the density of these dimples are increased after the vibration applied in welding. River marking, the characteristic of cleavage fracture, is observed in the heat-affected zone (HAZ) specimens. The possible solidification behaviour in VWC is discussed in this paper.