Abstract: This invention concerns a process of welding by an electron beam. The process is one in which the beam is rapidly deflected from point to point of a predetermined matrix of spots over which the beam rests for predetermined lengths of time in order to produce a predetermined distribution of energy over a defined area along the surface of the material being welded along a seam formed at the adjacent edges of workpieces. The length of time the beam is maintained at each position and the total beam power may be varied from spot to spot in order to produce a desired distribution of energy over a given area. This process is useful to avoid defects in partial penetration welds and in the welding of joints in which the gap between the edges to be welded may approach the diameter of the electron beam. The method is also useful in avoiding defects which may normally occur at the beginning and end of a weld seam.