Abstract
The performance of pulsed current gas metal arc welding (P-GMAW) and conventional gas metal arc welding (GMAW) processes in welding of 2.5 mm thin stainless steel sheet at different heat input has been studied. The use of P-GMAW at low heat input has been found superior to the use of GMAW process with respect to significant reduction in intergranular corrosion (IGC) susceptibility along with considerable improvement in some other characteristics of weld joint by maintaining comparable mechanical properties. It was further observed that the IGC, weld geometry and microstructure of P-GMA weld joint are largely governed by pulse parameters, and varies as a function of factor φ, defined as a summarized influence of pulse parameters such as peak current, base current, pulse-off time and pulse frequency. The increase of φ has been found favourable to reduce IGC, weld geometry along with refinement of the cast (dendritic) structure of weld deposit.
