The influence of heat treating on mechanical properties as well as on the sliding wearbehavior of sintered Fe-1.SMo-0.7C steels was experimentally studied. The microstruc-tures of sintered steels change from upper bainite to martensite, tempered martensite,pearlite and lower bainite depending on the heat treating conditions. Heat treatingincreases the hardness of sintered steels but high tempering temperature, i.e. 700℃,causes the hardness to be even lower than that of the as-sintered ones. The impactenergy of sintered steels increases with increasing tempering temperature and arrivesthe highest at 700℃, while the steels tempered at 200℃ have the highest transverserupture strength. Austempering results in fair good overall properties, such as hard-ness, impact energy, and transverse rupture strength. When the sintered steels wereaustempered, oil-quenched or tempered below 400℃ after quenched, the wear coef-ficient becomes considerably lower. Fair high hardness, such as HV30 ＞ 380, andstructures of martensite, tempered martensite or lower bainite are beneficial to low-ering the wear coefficient. Under the wear test conditions given, delamination andoxidational wear are the main wear regimes for sintered Fe-1.5Mo-0.7C steels. Fe3O4in the wear debris is beneficial to lowering wear coefficient.
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