Enhancing the strength and toughness of high-Cr high-Si F/M steel for nuclear power applications by optimizing hot rolling deformation amount

Abstract

High-Cr high-Si ferritic/martensitic (F/M) steel has emerged as a key candidate material for nuclear power equipment due to its excellent radiation resistance and corrosion resistance. However, the high Cr and Si contents lead to a greater proportion of ferrite, which can reduce the material’s strength and toughness and affect the type and distribution of second phase particles, thereby limiting its application in nuclear industry environments. This study optimizes the microstructure of High-Cr high-Si F/M steel by adjusting the hot rolling deformation amount, achieving the best match of strength and toughness. The mechanisms of strength enhancement are also investigated to clarify the relationship between microstructure and performance. The results show that a deformation amount of 40% during hot rolling yields the best overall performance, characterized by a low ferrite content, fine MX-type carbides with a high number density, and excellent strength and toughness. Rolling at the austenitization temperatures significantly improves the material’s comprehensive properties, providing strong support for the application of high-Cr high-Si F/M steel in the nuclear power sector.