THE ABRASIVE WEAR-RESISTANCE OF THE CARBIDE GROUP-6 AND GROUP-8 HARDFACING MICROSTRUCTURES - THE EFFECT OF ABRADENT TYPE

This paper describes an investigation aimed at evaluating the effects of abrasive medium type, viz. silicon carbide and river sand, on the w ear resistance properties of the Groups 6 and 8 carbidic hardfacing mi crostructures. It was observed that a low alloy material with a fine d ispersion of M7C3 carbides in a lenticular martensite matrix yielded t he most promising and economical iron-based wear resistant material fo r high stress abrasive wear conditions. The relative abrasion resistan ce of the low alloy materials is significantly dependent upon chemistr y and especially upon the chromium:carbon and total carbide former add itions:carbon ratios. The dendritic high alloy material wear propertie s were insensitive to bulk chemistry considerations, while the primary carbide microstructures exhibited wear properties which were highly d ependent upon chemistry and microstructure. Finally, the best wear pro perties were shown by the Fe-Cr-C eutectic microstructures. However, f rom a practical viewpoint this microstructure was difficult to attain because of the stringent boundary chemistry conditions.