TWI Industrial Member Report Summary 342/1987
By R V Sharples, G M Workman and T G Gooch
The investigation assessed the possibility of producing a nomogram for the general avoidance of solid state cracking in weld deposited hardfacing alloys, using Stellite 12 as an example. This cobalt-based alloy is widely used as a wear-resistant hardfacing material, but it is known to have a tendency to crack during cooling. The programme was designed to produce layers of Stellite 12, of varying dilution, deposited onto a 0.4%C steel by manual metal arc (MMA) welding, and to determine the extent of cracking in one-layer and two-layer deposits. The consumables were deposited onto a rotating steel bar, thermocouples were harpooned into the weld pool to record the cooling curves, and cracking was detected aurally and by dye-penetrant testing. Metallographic examination was carried out.