Yttria dispersed 9Cr martensitic steel synthesized by mechanical alloying hot isostatic pressing

摘要

Materials development for Generation IV power plant systems aims to provide significant improvements in economics, safety, proliferation resistance and sustainability. Oxide Dispersion Strengthened (ODS) Ferritic/martensitic or ferritic steels offer the potential for revolutionary improvements in high temperature performance, corrosion and radiation resistance, high resistance to thermal recovery of the material structure, and also meet low activation criteria. Hence ODS alloys significantly advance the performance of components for all the primary Generation IV concepts. This paper describes the synthesis of ODS 9Cr Martensitic steel by Mechanical Alloying of elemental metal precursors. Nanocrystalline yttria used as the dispersoid was synthesized via an efficient and economic Sol-Gel method. Optimization of the process parameters involved in the synthesis of ODS alloy powders have been established through detailed characterization of the synthesized alloy powders employing XRD, SEM/EDAX, TEM and Particle size analyses. The synthesized alloy powders were Cold Isostatically Pressed and subsequently Hot Isostatically Pressed at 1273K/1.2kbar pressure. Detailed microstructural characterization studies of the compacted specimens are reported.