GB1389271A - Fusion welding processes - Google Patents

Abstract

1389271 Welding by fusion; making welding wire GENERAL ELECTRIC CO Ltd 19 Oct 1973 [21 Aug 1972] 38910/72 Headings B3A and B3R In a method of fusion welding together two metal workpieces (e.g. tubes, end-to-end, or plates), wherein an insert is placed between the workpieces before application of heat, said insert is made by inserting a deoxidant-including metal powder, granules, filings or foil filling into a tube of weldable metal or alloy, preferably the same as one or both of the workpieces, consolidating, as by swaging, the filled tube to form a composite rod and working, as by swaging, rolling or pressing, to form said insert. The thus formed insert may be wire which may be subsequently rolled to produce a flattened strip insert. The formed insert may be annealed to promote some diffusion between the metal of the tube and the filling. The method is particularly suitable for welding by electron beam (glow discharge or thermionic cathode). In examples, strips of Nb, Ti or Zr foil or a mixture of Fe and Si powders are/is inserted into a mild steel tube (0À25 inch O.D., 0À05 inch wall thickness) which is then cold swaged first to rod and subsequently to a 0À125 inch diameter wire. The inserted Nb, Ti, Zr or Si, serving as a deoxidant, constitutes approximately 1% composite weight. The composite wire insert is placed in a channel constituted by grooves formed in the mating edges of 0À25 inch thick mild steel workpiece plates, and welding is effected by glow discharge electron beam.