Experimental research on electron-beam welding technology with a scanning electron beam

In this paper the question of achievement of quality welded joints in electron-beam welding is considered. The welded seam is largely characterized by its depth, width and their relation. The parallelism of the sides of the penetration zone plays an essential role, as well as the radius of the root part and other geometric parameters that affect the nature and magnitude of the welding deformations and stresses in the welded products. Traditional welding regimes entail root defects, porosity, undercuttings and fissures, and these are unacceptable in the manufacture of critical products. To obtain the required seam geometry various technological methods are used, for example, various forms of electron beam scanning with the programming of energy along the trajectory; the use of welding with different focus positions; oscillation of the electron beam; programming of change of current and focus at the beginning and end of the welding process. Nine difference trajectory scans were programmed in order to manage the energy distribution of the electron beam across the heating spot.

The effect of various forms of energy distribution across the heating spot on the process of formation of a welded seam and its characteristics was studied in this research. The quality of welded joints was evaluated by the results of the x-ray control of welded joints and microsections of the cross-section and longitudinal section of the welded joints. (paper)