A new improved oxide dispersion strengthened (ODS) Eurofer steel was produced by a novel two step mechanical alloying route. Starting from atomized Eurofer powder, two batches of fine and coarse particles with average sizes of ~60 μm and ~120 μm were milled separately after the addition of Ti and nanosized Y₂O₃. The final blend of the two powder batches was synthetized by hot isostatic pressing (HIP) to obtain a fully dense material with a microstructure characterized by two distinct zones: zones with high density particles (HDPZ) and zones with low density particles (LDPZ). The mechanical properties of the processed material in the as−HIP state and after tempering have been improved significantly compared to various ODS Eurofer and ODS Fe–Cr steels treated by different thermomechanical processing routes (TMP). The stress−strain curve at 600 °C manifested softening while a steady state constant stress was observed at higher temperatures. The stress exponent was two times lower compared to the base Eurofer material; i.e. ~12 vs ~24. Dynamic grain refinement was observed together with ferrite to martensite transformation resulting in an increase in ferrite−martensite interfaces and formation of low angle grain boundaries (LAGBs). Electron back scatter diffraction (EBSD) technique was used to characterize the microstructure and analyze the deformation mechanism.

通过新颖的两步机械合金化工艺生产了一种新的改进的氧化物弥散强化（ODS）Eurofer钢。从雾化的Eurofer粉末开始，在添加Ti和纳米级Y ₂ O ₃之后，分别研磨两批平均粒径分别为〜60μm和〜120μm的细颗粒和粗颗粒。通过热等静压（HIP）合成两批粉末的最终共混物，以获得具有微结构的完全致密的材料，其特征在于两个不同的区域：具有高密度颗粒的区域（HDPZ）和具有低密度颗粒的区域（LDPZ）。与通过不同热机械加工路线（TMP）处理的各种ODS Eurofer钢和ODS Fe-Cr钢相比，处于as-HIP状态和回火后的加工材料的机械性能得到了显着改善。600°C时的应力-应变曲线表现出软化，而在较高温度下观察到稳态恒定应力。与基础Eurofer材料相比，应力指数低两倍。即〜12对〜24。观察到动态晶粒细化以及铁素体到马氏体的转变，导致铁素体-马氏体界面的增加和低角度晶界（LAGBs）的形成。电子背散射衍射（EBSD）技术被用来表征微观结构并分析其变形机理。