The frequent and deep load cycling of thermal power plant boilers can lead to significant temperature variations in components such as superheaters

thereby increasing the risk of corrosion failure. This necessitates in-depth research to optimize boiler operation and safety. Therefore

in this study

a novel analysis framework combining combustion heat transfer numerical simulations and corrosion experiments is employed to systematically investigate the temperature field fluctuations under different load-cycling conditions

identify high-risk corrosion failure zones

and explore the steam-side corrosion and oxide film spalling characteristics and mechanisms of typical materials such as T91 in corresponding cyclic-variable-temperature supercritical water. The results show that when the boiler load varies between 100% and 30%

the temperature fluctuation in the horizontal section of the outermost pipes of the screen superheater can exceed 100℃

making it a high-risk zone for corrosion failure. Furthermore

steam-side corrosion studies of the typical material T91 in cyclic-variable-temperature supercritical water at 500℃ to 600℃ reveal that

unlike in constant-temperature supercritical water

cracks are more likely to form between the inner and transition layers of the oxide film under cyclic-variable conditions

increasing the risk of film cracking and spallation. Additionally

the transition layer promotes the formation of a non-uniform chromium-rich oxide layer below it

exacerbating substrate damage. The results offers theoretical guidance for material selection and safe operation of boilers.