Effects of ZrC addition on the recrystallization behavior of ZrC-dispersion strengthened FeCrAl alloys

ZrC-dispersion strengthened FeCrAl (ZrC-FeCrAl) alloy is one of the promising cladding materials for advanced nuclear reactors. The thermal stability of ZrC-FeCrAl alloy is closely associated with its recrystallization behavior. In this study, the effects of different ZrC contents (0–1.5 wt%) on the recrystallization behavior of FeCrAl alloys were investigated. It was found that ZrC addition impedes the recovery and recrystallization processes, with higher ZrC content resulting in higher recrystallization temperatures. Specifically, the addition of 1.5 wt% ZrC increased the recrystallization finishing temperature from 700 °C to 1000 °C. ZrC delays the initiation and completion of recrystallization as well as the onset and termination of grain growth, with higher ZrC content leading to more pronounced delaying effects and extended incubation periods for recrystallization. Furthermore, ZrC influences recovery and recrystallization by affecting the precipitation of M₂₃C₆ and Al₂O₃. ZrC addition also significantly enhances both room-temperature (RT) and high-temperature strength of the alloys. While low ZrC content markedly improves ductility, excessive ZrC content can impair it. The FeCrAl alloy with 0.5 wt% ZrC exhibited the best comprehensive mechanical properties. Moreover, with increasing ZrC content, the fracture mode of the alloy shifts from ductile to brittle fracture.