Effects of additional compensation shielding gas on stainless steel pulse MIG welding

Abstract

The paper proposes a novel processing method of additional shielding gas for compensation to overcome welding defects, which often occur when high temperature solid and liquid phase welds are exposed to air. This method properly modifies the current pulsed MIG welding device by adding an airflow control branch of shielding gas for compensation, so that weld formation of the high-temperature, solid-liquid phase from the welding torch nozzle can be manually intervened and secondary gas protection of the weld surface can be implemented. This modified welding device with additional airflow is then used to conduct bead-on-plate pulsed MIG welding experiments using 18-8 type austenitic stainless steel as the base material. The study of microstructure and physical properties of the weld indicates that after introducing a certain amount of shielding gas for compensation, not only is weld formation significantly improved, but there is also timely track and protection of the weld surface. This largely inhibits the occurrence of welding defects during high-speed pulsed MIG single-wire welding and helps improve welding efficiency, and this study might demonstrate the necessity of further research and exploration.