Role of beam oscillation on electron beam welded zircaloy-4 butt joints

Effect of beam oscillation on microstructure, mechanical properties and corrosion behaviour of electron beam butt weld of zircaloy-4 was investigated. Joints made with beam oscillation demonstrated higher ductility, toughness and notch tensile strength and higher corrosion resistance than the joints prepared without beam oscillation. Heat mixing and faster cooling associated with beam oscillation restrict unidirectional crystal growth favouring the development of a more uniform, fine basketweave widmanstatten structure in the fusion zone. Improvement in mechanical and corrosion properties using beam oscillation was attributed to the development of a more uniform microstructure, lesser segregation and lesser intermetallic precipitation in the fusion zone.