Surface assessment in low alloyed Cr–Mo sintered steels after heat and thermochemical treatment

Surface treatments, besides heat treatments, have been applied to a low prealloyed sintered steel with a composition of Fe–3%Cr–0.5%Mo. Special attention was paid to understand the interrelation of microstructure features with wear behaviour. In sintered materials open pores perform an important role on final behaviour, properties level and reliable service. Pores can be modified by using warm compaction techniques, as well as by surface secondary treatments. In this paper, the synergic effect of both factors on final properties, warm and cold compaction as processing parameters and quenching, steam treatment and nitriding as post-sintering treatments have been discussed. Materials have been prepared with different carbon additions by pressing at 700 MPa and sintering up to 1250 °C. Wear resistance investigations were done under dry sliding conditions varying the applied load.