Microstructural evolution and oxidation behavior of 13Cr-ODS steel tube after exposure at 1200 °C

Artikel i vetenskaplig tidskrift, 2026

Oxide dispersion-strengthened (ODS) steels are attractive candidates for fuel cladding in Generation IV reactors, due to their exceptional radiation resistance and high-temperature stability. This study investigates the microstructural evolution and oxidation kinetics of industrial pilgered 13Cr-ODS steel tubes during isothermal exposure at 1200 °C. Results indicate that the initially deformed, fibrous grains undergo partial recrystallization and significant grain coarsening after 20 h of exposure. This structural degradation is driven by a compromise between high stored deformation energy and Zener pinning from nano-oxides. High-temperature oxidation follows a transition from linear to parabolic growth kinetics, with a rate constant of approximately Kp = 54.32 mg2 cm−4 min−1. Characterization reveals a non-protective bilayer oxide scale consisting of an outer Fe3O4 layer and a porous inner FeCr2O4 spinel layer.