Abstract
Welding processes are widely used technologies in the industrial context for creating permanent connections between mechanical components. This popularity is due to their versatility, which arises from the numerous available process variants and the multiple advantages they offer compared to other joining techniques. In the manufacturing context, where devices often operate in extreme conditions, the quality of welds becomes a critical factor in ensuring the safety and reliability of the manufactured products. Additionally, the increasingly stringent design specifications demanded by customers must be carefully considered. To address these needs and to define the optimal roadmap for the investigated process condition, an experimental investigation was conducted on the Submerged Arc Welding process. The experimental trials involved butt joints of ASTM A516 Gr.70 carbon steel plates with different thicknesses in a flat position, utilizing a U-shaped chamfer and a multi-pass welding technique. For each weldment, the effects of the main process parameters on the qualitative characteristics of the manufactured products was evaluated from a metallurgical perspective. This evaluation included an in-depth metallographic analysis, which measured the dimensions of the heat-affected zones and the amount of ferrite and perlite in the final joint microstructure. Furthermore, the joint quality was assessed with regard to mechanical strength through hardness measurements. By analysing the experimental data, the paper provides a valuable contribution for increasing the productivity of the investigated welding process, while simultaneously meeting the specified industrial quality requirements for the products made of medium-thickness carbon steels.