Performance assessment of CMT over GTA welding on stacked thin sheets of CRNGO electrical steel

Abstract

Gas Tungsten Arc (GTA) welding remained to be a globally employed welding process used in industries to date. One among such is associated with the stators, used in hybrid electric vehicles (HEV) and electric motors (EM). The Cold metal transfer (CMT) process can be a possible alternative due to its pulsed and complete robotic welding system as compared with conventional and pulsed GTA welding. The paper focuses mostly on joining the stacks of Cold rolled non-oriented (CRNGO) electrical steel sheets (ESS) composed of thin sheets (0.5 mm) largely used in stators of HEV and EM, by using CMT process. A systematic approach is adapted to highlight the investigations made after using the CMT process over a conventional GTA welding process, largely employed in joining the CRNGO electrical steel sheets. The paper also investigates and compare the mechanical (hardness variation), macroscopic (weld seam characterization) and microstructural investigations (using Scanning electron microscopy) of the welded samples of CRNGO electrical steel, post-GTA, and CMT welding. The study can be used as a reference and alternative method for welding on stacks of thin electrical steel sheets using CMT.