SUBMERGED ARC WELDING OF BUTT JOINTS OF GRADE A SHIPBUILDING STEEL SHEETS ON ONE SIDE IMMEDIATELY AFTER PLASMA CUTTING

This study is dedicated to developing approaches for applying submerged arc welding to extended sheet shipbuilding structures (such as panels and beams) made of low-carbon steel immediately after plasma cutting, without additional edge preparation. The selected submerged arc welding parameters allow for achieving satisfactory weld quality when welding edges produced by plasma cutting without further processing. A positive effect was observed in all specimens. It has been established that without securing the welding head to the deforming surface of the welded components, the electrode overhang decreases, and welding mode parameters change up to arc interruption. Specialized equipment is required to correct such deflection, and the presence of weld reinforcement complicates the straightening operation. Furthermore, conventional single-sided, single-pass submerged arc welding on ceramic forming backing strips, despite the beneficial influence of the substantial heat capacity of the welding flux, leads to the formation of hardened microstructures in the weld metal and reduces its ductility due to significant cooling rates and the rapid progression of phase transformations.