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In the present experimental work, the effects of vanadium additions on the microstructures and mechanical properties of powder metallurgy (PM) steel and microalloyed powder metallurgy (PM) steels were investigated. The microstructures of the PM steel and microalloyed PM steels were characterized by optic microscope, SEM and EDS. Experimental results showed that vanadium microalloyed steels can be produced by PM technology. The addition of vanadium limits grain growth during austenitization prior to air cooling and increases the strength in the sintered conditions. By limiting austenite grain growth, the precipitates result in significant improvement in strength.

Abstract:In this work, the effects of NbC additions on the microstructure and mechanical properties were examined. In order to do this, NbC compounds were added into the Fe matrix at the weight percentage of 0.1-2 with individually to obtain powder mixture. The microstructure of the powder metallurgy (PM) steels were characterized by optic microscope, scanning electron microscope (SEM) and energy dispersive spectroscopy (EDS). Experimental results indicated that NbC alloyed steels can be produced by PM technology. An increase in strength was observed when the amount of NbC compounds increased for all PM steels. The precipitation of carbides and nitrides in these steels limits austenite grain growth and increases the precipitation hardening or clustering hardening that results in significant improvement in strength.