In GMAW welding, there are several types of metal transfer that are primarily determined by the primary welding parameters. Different metal transfers in an electric arc are characteristic of different applications. In this paper, a detailed characterization of the pulse transfer of metals in an electric arc is performed, including the characterization of parameters and criteria for their selection on the used power source for welding Welbee. For a given Welbee device, the choice of parameters in steel welding is shown, as well as the synergy function that is characteristic of these devices. Welding was performed on structural steels, with previously adopted parameters, accompanied by recording the dynamic characteristics of current and voltage with an oscilloscope. Based on the available literature sources, the existing models for heat input calculation in GMAW pulse welding were analysed in detail. Heat input calculation for welded steel sheets was performed by using one of them, with current and voltage profiles recorded with an oscilloscope. After the experiment, the obtained results were elaborated, and general comments were given regarding influence of parameters on the quality of welded joints.