Porosity variation along multipass underwater wet welds and its influence on mechanical properties

The objective of this work is to evaluate the influence of porosity variation on multipass V-groove weld metal properties. Commercial covered electrodes (E6013 and E7024) and three different steels (A-36, A-572 and API 5L grade B) were used to perform the wet welds at 50 and 100 m depth. A pressurized chamber with 20 atmospheres capacity was used to simulate the depth with fresh water. A gravity feeding system was used to perform the welds. The porosity in transverse cross-sections, Charpy V-notch tests, side bending tests and tensile tests were determined for correlation. Samples for porosity measurement removed in four different points along the weld length showed decreasing porosity. Mechanical tests showed better properties in the samples extracted from the end of the welds.