The electron beam welding process of titanium alloys induces a series of physicochemical changes in the material that remain a relevant and necessary area of investigation. A necessary step performed after the electron beam welding process of titanium alloys in the Ti6Al-4V grade to mitigate the resulting thermal stresses is the post-weld heat-treatment process conducted through stress relieving. This study presents the comparative analysis results of the mechanical properties and structure of the Ti6Al-4V titanium alloy after electron beam welding and subsequent stress-relieving heat treatment at a temperature of 590 °C for 2 h. The analysis focused on the levels of mechanical properties such as microhardness in the heat-affected zone and weld, tensile strength, and microstructure analysis in the heat-affected zone and weld. The aim of the research was to answer the questions regarding whether the post-weld heat treatment through stress relieving after electron beam welding of the Ti6Al-4V titanium alloy would significantly affect the changes in mechanical properties and microstructure of the alloy and whether the applied welding speed in the study would cause a significant depletion of alloying elements in the material. During the course of the study, it was found that conducting the electron beam welding process at a speed of 8 mm/s resulted in a depletion of one of the alloying elements (aluminum) in the face area. However, the decrease in aluminum content was not significant and did not exceed the critical value of 6% specified in the material standards, which determined the material’s application based on its strength properties.

The paper covers a study consisting on the implementation of the electron beam welding process of two steel grades: 39CrMoV13 and M50NiL. The welding process was carried out for two values of electron beam debunching, obtaining a joint having different widths. Then, for the samples, after each welding variant, heat treatment was carried out consisting of double tempering at 520 °C for 3 h, and single freezing at − 84 °C for 3 h, combined with single tempering at 520 °C for 3 h. The impact of the parameters of the electron beam welding process and the subsequent heat treatment process on the mechanical properties and microstructure of the resulting joint was analysed. The conducted tests allowed to select the optimum welding technology combined with the heat treatment process for the tested steel grades ensuring that a weld is obtained in which the level of mechanical properties was close to the level of values obtained for the base material.