TWI Industrial Member Report Summary 469/1993
By D J Abson
In a previous phase of this programme, plasma transferred arc (PTA) deposits produced from a mixture of chromium boride and austenitic stainless steel were high-lighted as a prototype hard-facing material. Alternative methods of deposition have been explored in the present programme. Chromium boride powder, mixed with 304L stainless steel powder, has been deposited on steel substrates by the following processes.
i. Friction surfacing, with the mixed powders being contained in stainless steel tubing, and also with such tubing containing cored wires which had chromium boride in the fill.
ii. Manual metal arc welding, using both rutile and basic electrode coatings.
iii. MAG welding, employing the cored wires mentioned in (i) above.
iv. Laser welding, using pneumatic feeding of the mixed powders. Two layer deposits were produced by the arc processes and by laser welding, and single-layer deposits by friction surfacing. Investigation of the deposits has included chemical analysis, metallographic examination, hardness measurement and pin-on-disc wear testing.