Alloying pre-alloyed Fe-Mo powders by silicon carbide addition

This work demonstrated that the silicon carbide addition to pre-alloyed Fe-Mo powder could result either in the formation of steel or iron microstructure depending on the added silicon carbide content. With 1.0 wt. % silicon carbide addition, slowly cooled sintered Fe-Mo-Si-C alloys showed steel microstructures consisting of proeutectoid ferrite and eutectoid transformation product in the form of ferrite + carbide mixture. With 2.0 wt. % silicon carbide addition, slowly cooled sintered Fe-Mo-Si-C alloys with Mo contents of ≥ 0.85 wt.% microstructures comprised ferrite + austenite constituents in the forms of either degenerate upper bainite or ausferrite. With ≥ 3.0 wt. % silicon carbide addition, ductile iron-like microstructures were developed in sintered Fe-Mo-Si-C alloys. The change of microstructures in experimental sintered alloys was attributed to the combined effect of alloying molybdenum, silicon, and carbon elements. Tensile strength and hardness increased with increasing added SiC content while ductility varied with microstructural components.