Properties of Sintered Compacts Made of Ni-Free Pre-Mixed Powder Based on Low Mo Prealloyed Steel Powder

摘要

A new pre-mixed powder based on a low Mo prealloyed (0.45mass%) steel powder added to copper (2mass%) and graphite (0.8mass%) has been developed. Sintered with a mesh-belt sintering furnace the developed powder makes it possible to produce P/M parts with a strength equivalent to the conventional 4mass%Ni diffusion-alloyed steel powder in as-sintered condition. The sintered compacts of FM series provide less than one fifth the tool wear of that of the conventional 4%Ni diffusion-alloyed steel powder. The high strength despite lower alloy content should be attributed to both a strengthening by fine pearlite transformation at molybdenum prealloyed steel powder particles and a strengthening of sintering neck by copper powder addition.