To the conception of reducing the residual stresses at the electron beam welding in welded joints caused by thermoelastic phenomena

The article deals with the concept of reducing the residual stresses resulting from the phenomena of thermoelastic and thermoplastic metals in welded joints at the electron beam welding (further EBW). On the basis of the analysis of mechanical and thermophysical characteristics of the dynamics of electron-beam welding (EBW) process it is shown that the cause of distortion of the products surfaces is in thermoelastic surface waves that determine the main phenomenon, precisely the longitudinal - transverse bending of the product after the welding process due to the residual welding stresses. The basic model of the process is presented and the model of the phenomenon, that takes into account the structural changes in the accumulation of material to be welded and the relaxation of strain in structural transitions, is developed. The attempt of taking into account the loading history of the material that undergoes a phase transition in this type of welding is made the first time. The problem has also the applied meaning because the cost of such welding is high and reduction of the defect rate can significantly increase the profitability of production.