The work aims to evaluate the possibility of increasing the resistance of 50MnSi4 steel to wear by hardfacing Fe-Cr-C-Mo type alloys. For this purpose, two types of filler metals for gas metal arc welding (GMAW) were used -Carbofil A 350 and Magmaweld FCH 360. Metallographic evaluation of the hardfacing structure was performed on the prepared samples, supplemented by hardness measurement. Standard tribological tests were used to test adhesive and abrasive wear resistance. The test results clearly showed that the types of filler metals used for weld cladding significantly increased the resistance of the 50MnSi4 steel substrate to adhesive and abrasive wear. When evaluating the adhesive wear, the positive effect of the hardfacing was manifested not only by a decrease in the weight loss of the samples but also by the coefficient of friction. In the case of the evaluation of resistance to abrasive wear, the best indicators were found in the application of the filler metal Magmaweld FCH 360, where the highest hardness of the martensitic structure of the hardfacing 719 HV0.2 was noticed. K e y w o r d s : hardfacing, weld cladding, gas metal arc welding, adhesive wear, abrasive wear

This work presents a new technology for joining dissimilar materials, Resistance Element Soldering (RES). This technology is fundamentally based on Resistance Element Welding (REW) technology; the difference is that the presented RES uses a bimetallic element composed of a hard Cu shell and a core made of Sn60Pb40 solder. The RES technology using the Cu/Sn60Pb40 bimetallic element was tested when joining a galvanized steel sheet (HX220BD-100MBO) to a thermoplastic (PMMA). The effect of the process parameters on the volume of the melted solder, the deformation of the element, and the structure of the soldered joint was investigated on the joints made. The final criterion for assessing the influence of the process parameters was the joint strength. Due to the low strength of PPMA, the maximum joint strength was determined on RES joints of galvanized steel sheet and aluminum. The results showed that, to ensure the joint strength at the level of the strength of the Sn60Pb40 solder used, a heat input of 952 J and a clamping force of 623 N are required. The mentioned parameters ensure the necessary conditions for the creation of a soldered joint with a galvanized steel sheet as well as the deformation of the bimetallic element to create a form-fit effect in the opening of the PMMA to create a mechanical connection.