Mechanical and microstructural characterization of P/M high-speed steel valve seat inserts

This work presents the use of high-speed steels, for valve seat inserts application. Two types of materials were evaluated, one made on purpose high speed steel M3/2 mixed with iron powder and niobium carbide and another valve seat insert made of Fe-Co alloy used for comparison. The microstructure of the valve seat insert was evaluated by scanning electron microscopy. The physical and mechanical properties of the inserts studied are presented in terms of densification, hardness, radial mechanical strength and machining. The results showed that the made on purpose material is a potential candidate for the fabrication of valve seat inserts, with additional economic advantage over traditionally used Fe-Co alloys.