High power electron beam welding of thick section steel with filler wire additions

TWI Industrial Member Report Summary 453/1992

By C S Punshon and J M Kell

Background

The exploitation of high power electron beam (EB) welding in heavy fabrication is limited, to some extent, by the dependence of the process on good fit-up and material quality to achieve appropriate weld integrity and mechanical properties. In this report, the addition of filler material via wire feed is examined as a potential technique for improving the tolerance of the process to poor fit-up and for reducing dependence on parent metal composition to achieve good toughness.

Design and installation of a wire feed system in TWI's 75kW, 150m³ EB2 facility are described. Methods for the addition of wire to fully penetrating welds in 80mm C-Mn steel to BS1501-224 490B are investigated.

Commercially available Nickel alloy filler wire was added to welds to assess the degree of mixing occurring and the effect of joint gap on achievable weld quality. Also, filler additions were made with an experimental powder cored steel wire to investigate the possibility of improving weld metal microstructure and toughness properties.