Mechanical and Microstructural Characteristics of Conventional and Robotic Gas Metal Arc Welded Low Carbon Steel Joints: A Comparative Study

In the recent automobile era, SAE 1022, low carbon manganese steel is widely used in structural members of automobiles. These steels possess good weldability and need proper heating treatment conditions when high thickness sections are being used in the structural application. Mostly, gas metal arc welding (GMAW) is preferred in automobile industries to have which produces better penetration with some minor defects like improper fusion of sidewall, etc. The increasing demand in the field of the automobile led to the attention over automated GMAW is being preferred to reach better productivity with zero defects. The samples were welded by the conventional GMAW method and automated through a robot. From the experimental test results, welding current of 450A, welding speed of 350 mm/min and a land height of 4 mm yielded a maximum tensile strength of 647 MPa and hardness of 275 HV in the coarse-grained heat-affected zone region with a robotic mode of GMAW. The comparative study proved that automated process produced better mechanical properties and improved efficiency.