TWI Industrial Member Report Summary 326/1986
By C S Punshon
A frequently encountered design requirement for electron beam welding is to produce welds in a circular configuration. For this type of weld and occasionally in some linear welding applications, it is necessary to terminate the welding process by a beam fade-out operation in which the beam current is reduced progressively to zero. In thick section electron beam welds, the occurrence of defects in the fade-out region is a common cause for rejection and hence it is of considerable importance to develop methods for eliminating these problems. In this report, the factors affecting the formation of defects in the fade-out region are considered. The results of an experimental programme designed to investigate the influence of various weldiig parameters on the occurrence of defects are presented with particular reference to the effects of beam focus position on partial penetration weld shape.