TWI Industrial Member Report Summary 252/1984
By Y Komizo, C S Punshon, T G Gooch and P J Blakeley
The solidification structures have been examined of electron beam welds in C-Mn and Ni alloy steels and a duplex stainless steel used in 25mm thickness. A range of beam powers travel speeds and beam deflection patterns was employed.
In all materials, a transition in weld centre-line structure was observed from elongated crystals parallel to the welding direction (raft structure) to an interlocking structure of columnar crystals growing virtually normal to the fusion boundary. The transition was found to depend mainly on increasing travel speed, this being considered a result of the associated change in weld pool shape.