Modeling of growth stress gradient effect on the oxidation rate at high temperature
Fan Yang, Bin Liu, Dai-ning Fang
Applied Mechanics Laboratory, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China, State Key Laboratory for Turbulence and Complex Systems, College of Engineering, Peking University, Beijing 100871, China
Abstract A new oxidation kinetics model is established for high-temperature oxidation. We assume that the interface reaction is fast enough and the oxidation rate is controlled by diffusion process at high temperature. By introducing the growth stress gradient we modify the classical oxidation parabolic law. The modified factor of the oxidation rate constant is a function of growth strain, environment oxygen concentration, and temperature. The modeling results show that the stress gradient effect on the oxidation rate cannot be ignored. Growth strain will dominate whether the stress gradient effect promotes or slows down the oxidation process. The stress gradient effect becomes weaker at higher temperature. This effect is amplified at higher concentrations of environmental oxygen. Applied mechanical loads do not affect the oxidation rate. This model is available for high temperature oxidation of metals and alloys.
Fan Yang, Bin Liu, Dai-ning Fang. Modeling of growth stress gradient effect on the oxidation rate at high temperature. Journal of Zhejiang University-SCIENCE A (Applied Physics & Engineering), 2010, 11(10): 789-793.
