Optimization of submerged arc welding through voltage variation to achieve superior mechanical properties using P355N base material

Abstract

This study focuses on the optimization of the submerged arc welding (SAW) process through the variation of welding voltage to achieve improved mechanical properties of butt-welded joints made from P355N fine-grained low-alloy carbon steel as a material commonly used in the production of pressure vessels. The optimization process was carried out by analyzing the effects of different welding voltages on mechanical performance, including tensile strength, hardness, and metallographic characteristics. In addition to mechanical testing, the study evaluates weld geometry and the transition zones to provide a comprehensive understanding of how voltage variation can optimize the welding process and improve joint performance. The welded samples were obtained using five different welding modes, the primary variable of which was the intensity of the welding current with a voltage range of 22–38 V within a seemingly narrow range. Significant changes were identified in microstructure, mechanical properties, and the shape and size of the welded joints. The experimental samples were considered from welded joints made from 6 mm thick plates of P355N material. The reference criterion against which the welding modes under study were compared is the industry-standard welding voltage of 33 V.