Comparative study of mechanical strength between manual and automated GMAW welding processes

Abstract

This study performs a comparative analysis of mechanical strength between manual and automatic GMAW (Gas Metal Arc Welding) processes. The gas used is a mixture of carbon dioxide ($CO_2$) and argon (Ar), thus characterizing it as a MAG (Metal Active Gas) process. The research focuses on evaluating the mechanical and microstructural properties of welded joints in SAE 1020 steel. Tensile tests, Vickers microhardness, metallographic analysis, and thermographic inspection were conducted. The results indicate that automated welding provides greater microstructural homogeneity, less hardness variation, and more efficient thermal control, reflecting higher process reliability. In contrast, manual welding showed greater dispersion in the results, with high-hardness zones that may compromise mechanical performance. It is concluded that, while manual welding is still applicable in specific contexts, automation stands out as a more efficient alternative for industrial environments that require high repeatability and quality control.