To investigate the effect of different oxidation times on the oxidation behavior of Zr-Sn-Nb alloy in a high-temperature steam environment at 1250 degree celsius, steam oxidation tests were conducted on the Zr-Sn-Nb alloy at 1250 degree celsius for durations ranging from 100 to 5000 s. Microstructural and elemental composition analyses of the Zr-Sn-Nb alloy were carried out using scanning electron microscopy, energy-dispersive x-ray spectroscopy, and optical microscopy. The results showed that in the initial stages of oxidation (0-1000 s), the weight gain per unit area followed a parabolic tre...