The effects of alloying elements and microstructure on the impact toughness of powder metal steels

► We examined the effects of Mo, Cr, and Ni on the toughness of PM steels. ► The toughness of Fe-C alloys was decreased by Mo and increased by Ni and Cr. ► Mo also impaired the toughness of Fe-Ni-C alloys. ► Cr can improve the strength of Fe-Ni-C alloys without sacrificing toughness. ► A superior combination of strength and toughness can be achieved by alloy design.