Effect of heat treatment, lubricant and sintering temperature on dry sliding wear behavior of medium alloyed chromium PM steels

The influence of sintering temperature, heat treatment and lubricant on the wear rate of warm compacted Fe–3%Cr–0.5%Mo–0.45%C Astaloy steel P/M alloy [Astaloy CrM] was investigated using dry sliding wear test, X-ray diffraction and metallographic examinations. Observations showed that for warm compacted Astaloy CrM heat treatment by quenching and tempering at 450 °C reduces wear rate, while tempering at lower temperatures such as 200 °C has the adverse effect. In this case dominant mechanism was found to be delamination wear as evidenced by lustrous large metallic debris. Two different lubricants, i.e. Li stearate and stearamid were investigated. For specimens sintered at high temperature, Li stearate lubricant shows better wear behavior, whereas for low temperature sintering, stearamid will be a better lubricant regarding wear behavior of sintered product. Measurements of transverse rupture strength and wear rate confirmed that pores play a major role in both static and dynamic properties of PM parts.