TWI Industrial Member Report Summary 397/1989
By B G I Dance
The as-welded toughness of electron beam (EB) welds in thick section steels is frequently poor. In this report, three techniques for improving the as-welded toughness of EB welds in 50mm C-Mn steel to BS 1501-224 are investigated:
i. Producing a highly alloyed weld, with microstructure and phases present that are completely different from those normally encountered.
ii. Producing a weld with a lower carbon equivalent than the parent plate, with a greater proportion of ductile transformation products.
iii. Producing a weld with a fine, tough 'acicular ferrite' (AF) microstructure.
Various filler materials were added to the weld metal in order to promote such changes. Their effects were assessed by metallography, hardness determination, and Charpy testing.