Hojati, M., Gierl-Mayer, C., & Danninger, H. (2022). Monotonic And Cyclic Propertie OF Sinter Hardenedf PM Steels Prepared By Hybrid Alloying. In European Powder Metallurgy Association (Ed.), Proceedings World PM2022.
PM steel precision parts, high mechanical loading is very common in service. In particular for automotive applications, fatigue up to very high loading cycle numbers may be encountered. Advanced alloying concepts for sintered steels are required, involving also alloy elements with high oxygen affinity. In the present study, hybrid alloyed sintered steels were prepared based on prealloyed steel powder Fe-1.8%Cr, and Mn and Ni, respectively, were admixed as well as a masteralloy containing Mn and Si. After sintering the specimens were quenched with cold nitrogen, to simulate sinter hardening, and characterized. Ni alloying proved to be positive both for the impact energy and the gigacycle fatigue strength while Mn was less effective, in part because of intergranular embrittlement. The Mn-Si masteralloy also showed some intergranular failure, but in particular at N>10E8 the fatigue endurance strength was similar to that of the Ni alloyed type, however with lower scatter.
Using the hybrid sintered steels with high oxygen affininty in order to produce highly loaded PM parts, through admixig Chromium prealloyed powder with with elemental powders as well as a masteralloy powder.
