Electron Beam Welding of Heavy Section Steel Plates

Abstract

The electron beam (EB) welding process has been applied to heavy section steel plates mainly because of its high productivity and low heat input. There are, however, several problems to be solved, and the optimum condition to prevent defects in EB welded joints and the mechanical properties of EB welded joints have been investigated for eight heavy section steel plates.
The study revealed that the beam oscillation in the X direction (parallel to the welding direction) prevents defects, and the optimum condition for oscillation is the frequency of 100 Hz and the amplitude of 2 to 4mm. Under suitable welding conditions, the commercial steels can be applied to the EB welding of deep penetration without any modifications from the standpoint of the prevention of defects. Correlations have been found between the toughness and the carbon content of EB welded joints. The toughness improves with reduction o f the C content especially in the aswelded condition. The toughness of high C (≥0.20%) steels are extremely poor owing to the formation of high carbon martensitic islands. Therefore, modifications of chemical compositions are required for these steels.