THE MICROSTRUCTURE AND PROPERTIES OF LOW-CARBON PM Mn-Cr-Mo STEELS SINTERED UNDER DIFFERENT CONDITIONS

The paper presents the effect of sintering conditions on the microstructure and mechanical properties of low-carbon Mn-Cr-Mo PM steels. It was proved there is no effect of tempering temperature on the properties of Astaloy CrL-base steels, sintered at 1250◦C in 5%H2-95%N2 mixture as compared with the properties of those sintered at 1120◦C. The properties of Astaloy CrM-based steels, sintered at 1250◦C in air were comparable or higher to Astaloy CrL-based steels. The addition of lump of ferromanganese was not sufficient for metal oxides reduction. The structure investigation confirmed the earlier observations that Mn-Cr-Mo PM steels have predominantly martensitic or martensitic/bainitic microstructure