Consolidation process study of 9Cr-ODS martensitic steels

As a practical method to produce a large-scale annular billet made of 9Cr-ODS martensitic steels, a hollow capsule with outer and inner diameter of 147 and 32 mm, respectively, was filled with mechanical milled (MM) powders and were extruded by a 2000 ton press at 1423 K. Hot isostatic pressing was applied as a consolidation process of MM powders at 1423 K and 190 MPa for 3.6×103 s. The microstructure and formability of the HIPed product were investigated. The hot-extrusion behavior of the HIP-ODS alloy was also tested using a 2000 ton press. The compaction by the cold isostatic pressing with subsequent sintering is insufficient as a starting material for hot-extrusion.