PROBLEM TO BE SOLVED: To calculate an oxidizing velocity constant Kp of materials for high temperature equipment such as a boiler superheater and a reheater with high accuracy, and improve the predictive accuracy of a steam oxidation or a high-temperature water oxidation scale thickness diagnosed by using a value of the calculated oxidizing velocity constant Kp and an overheating creepage failure analysis accuracy by the scale, more than before.;SOLUTION: In the calculation method of an oxidation reaction rate constant (Kp), the log(Kp) is converted into a positive number by adding the constant, and a relationship between the log(Kp) converted into the positive number and the reciprocal (1/T) of an absolute temperature is calculated by the following regression equation (4) based on the power law. The equation (4) is log(Kp)+c=a×(1/T)^b, where (c) is a coefficient for converting the log(Kp) value into the positive number, (a) is a power law regression coefficient and (b) is a power law regression index. Also, a scale thickness (d) is calculated by using the calculation method from the equation of d=(Kp×t)0.5, and thereby a scale overheating damage is diagnosed for diagnosing the thinning due to the inner oxidation scale of a heating heat transfer pipe and the overheating damage due to the metal temperature rise.;COPYRIGHT: (C)2016,JPO&INPIT
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