The objective of this research work was to study the influence of the iron oxide phase resulted during steam oxidation of the sintered steels specimens obtained by powder metallurgy (P/M) route. Steam oxidation is a surface treatment applied to sintered iron parts, as an economic way to reduce the interconnected pores. In powder metallurgy products, the networks of pores are specific, who can be stress concentraions and can produce cracks in material. By steam oxidation treatment the interconnected porosity is closed by sealing them with iron oxides phases. Also, other properties of sintered PM steels are improved. The specimens analyzed in this paper were produced from atomised iron powders, compacted at room temperature at pressures of 600 MPa, sintered for 120 minutes at 1150o C in a laboratory furnace and then subjected to a continuous steam oxidation at 550o C for 60 minutes. Investigations on the structural, mechanical and abrasive wear properties were performed. The microstructure and the pore morphology of the sintered and steam oxidation samples were studied on using optical microscope.