Novel high performance, dimensionally controlled PM steels for sinter-hardening

Resumen:
A group of high strength, cost effective PM steels has been generated by combining alloying elements (e. g. Cr, Mo, Ni, Cu, Mn) in predetermined concentrations. The main aim was to optimise the balance between compressibility, hardenability and properties. Special efforts were devoted to identifying compositions and processing conditions giving specific proportions of transformation products (martensite, bainite, etc.) in an attempt to correlate microstructural characteristics with the mechanical properties of the sintered steels after tempering. Measuring dimensional changes after sintering as well as properties such as yield stress and hardness allowed processing conditions to be optimised for the composition and characteristics of the powder mixture.