Influence of Hot Extrusion Temperature on ODS Ferritic Steels

摘要

Direct hot extrusion of powder is the standard consolidation process to transform mechanically alloyed Oxide Dispersion Strengthened (ODS) steels into fully dense bars. Temperature of extrusion is one of the main parameters of this process. Its influence on the material microstructure and mechanical properties was investigated in this work. For this purpose, ODS steel bars were extruded at different temperatures ranging from 750 °C to 1100°C and characterized by TEM observations associated to hardness measurements. It was shown that it is possible to obtain finer microstructure with smaller grains and nanoscale-clusters for lower extrusion temperature. This finer microstructure is related to higher hardness which might be an issue for the material workability.