ELECTRON BEAM WELDING METHOD

PURPOSE:To perform butt welding without a defect such as a defective bead shape at the beginning and terminal ends of butt welding by positioning the focus of an electron beam upper or lower than the surface of members to be welded at the beginning end and terminal end of butt welding and welding said members. CONSTITUTION:The focus of an electron beam 3 is positioned upper or lower than the surface of materials 1, 1 to be welded at both ends of a butt part and welding is performed by matching the focus to the surface in the intermediate part in the stage of fixing the materials 1, 1 by means of clamps 6 via spacers 5, a backing strip 4, etc. and subjecting said materials to but welding by the beam 3. The generation of a welding defect such as the run at the beginning end, the keyhole at the terminal end, etc. is thus prevented without using an end tab and the good bead shape is easily obtd.