This paper presents the results of a study on the development of a Metal active gas (MAG) welding technology for an industrial furnace component made of steel S235JRC+N with respect to the minimizationof welding deformation. A numerical simulation of the welding process was performed in the first phase of the research. The numerical simulation was carried out with the SYSWELD software. For the numerical simulation of the welding process, the FEM method was used. In the simulation, four variants of restraint of the industrial furnace wall panel elements during the execution of the welding process were investigated. They differed in the number of restraints (model 1–4). It was found that the difference between the maximum mean strain in model 1 and the lowest mean strain in model 4 was only 11%. A physical simulation of the welding process was then performed with a restraint variant according to model 1. The displacement results obtained from the physical simulation of the welding process were compared with the displacement results from the numerical simulation. Discrepancies between numerical and physical simulation displacement values were found. The quality of selected welded joints was also evaluated. Visual testing (VT) and measurements of weld geometries were performed for this purpose. Metallographic tests and hardness measurements were performed to determine of influence of the welding process on the microstructure of the welded joint area, especially the heat affected zone (HAZ). The results obtained confirm the correctness of the assumptions made regarding the technology of manufacturing the furnace wall panels.

This paper presents the results of research on minimizing welding distortion in a large-scale storage tank bottom made of S235JR steel with a diameter of 10,000 mm. The welding technology previously employed guaranteed flatness tolerances of the bottom plates in accordance with the EN 14015 standard at a ratio of T = 0.25% × D = 25 mm, where D represents the diameter of the tank bottom. The objective of this study was to investigate the possibility of reducing this value to the target level of ΔT = 0.2% × D = 20 mm. Two clamping system configurations, used to restrain the tank bottom plates during welding, were analyzed. Numerical simulations of both configurations were performed using the finite element method (FEM) in the SYSWELD software. For the selected clamping configuration, a physical simulation of the welding process was carried out, followed by an analysis of the distribution of welding-induced distortions in the storage tank bottom with respect to compliance with the required bottom plate flatness tolerance of 0.2% × D.