The isothermal steam oxidation behavior of the Zr−Sn−Nb alloy at 1050 °C was studied. In this study, the oxidation weight gain of Zr−Sn−Nb samples with oxidation durations ranging from 100 s to 5000 s was calculated. The oxidation kinetic properties of the Zr−Sn−Nb alloy were obtained. The macroscopic morphology of the alloy was directly observed and compared. The microscopic surface morphology, cross-section morphology, and element content of the Zr−Sn−Nb alloy were analyzed using scanning electron microscopy (SEM), transmission elect...