b'Accomplishments: inhomogeneous material deformationFigure 1. Cross-sectional Comparisons of lab-scale C26M(and therefore microstructuremacrostructure of as-cast Fe-base alloy heats with minor alloyingevolution) during the hot-process.12Cr-6Al-2Mo-0.2Si (C26M) base alloys.additions were conducted, inOn the other hand, the Zr addition terms of microstructure evolutionpromoted the formation of equi-axed during solidification and thermo- grains (Figure 1) and supported mechanical processing, room- more homogeneous deformation temperature deformability, andduring hot-process, which resulted high-temperature oxidation resistancein a significant stabilization of fine, in a steam-containing environment.recrystallized grain structure with It was found that the Y addition~20-25 m of average grain size dominantly controlled the formation(Figure 2). By comparing with the Y of fine columnar grains in as-castaddition, the effect of the Zr addition microstructure (Figure 1), and causedon improving the microstructure 2019|AFC ACCOMPLISHMENTS 81'