Abstract
We herein delve into the corrosion dynamics of UG1 in high-temperature water, employing thermal acceleration to expedite reactions. Corrosion-induced changes in spectral properties, optical constants, and morphology are analyzed. The results reveal a phosphorus-poor layer near the surface that affects transmittance, refractive index, and extinction coefficient, with corrosion rates following a parabolic model. This study provides crucial insights for protecting UG1 in humid environments and emphasizes the importance of implementing protective measures against phosphorus diffusion.