Abstract：In this paper, impact of Si content on the evolution of Laves phase precipitates and the influence of such evolution on the mechanical properties of high-performance ferritic (HiperFer) stainless steel are investigated. Strengthened by solid solution strengthening and Laves phase precipitation, novel HiperFer stainless steel are designed for the application to next generation of ultra-supercritical thermal power conversion systems with superior steam-oxidation resistance and promising creep strength and thermomechanical fatigue resistance at 650℃. As typical distribution strengthened alloy, mechanical properties of HiperFer stainless steel are influenced by Laves phase precipitates and the precipitation evolution. And the precipitation and microstructure evolution of Laves phase are influenced by alloy chemical composition, such like Si. However, influence of Si content on Laves phase precipitation and mechanical properties of HiperFer steel are not fully understood. Thus, impact of Si on Laves phase precipitation evolution is systematically investigated in this research. And such investigation provides an economic approach for further optimization of HiperFer steels.
2022, Vol. 29 