Estimation of Creep Constitutive Law for Cr-Mo-V Material in Turbine Rotor Using Indentation Creep Test
Shinsuke SAKAI, Satoshi IZUMI, Takashi MURAKAMI, Akito NITTA, Junichi KUSUMOTO and Yu WATANABE
Abstract:In residual life evaluation of fossil power plants, improvement of accuracy of creep damage evaluation is extremely important. One of the powerful non-destructive evaluation methods is hardness test. This method is effective because it enables us the on-site evaluation and the results are obtained without laborious work. In this paper, the Vickers hardness test not at ambient but at high temperature is applied to turbine rotor material and the method for evaluating the creep constitutive law is newly developed. Firstly, the method to derive the creep constitutive law from hot hardness test is formulated. In this method, only the hot harness test results together with only one tensile creep test result are required at around operation temperature to evaluate the Norton law. Secondly, the formulation is applied to the experimental results of hot hardness test. It is shown that results evaluated by the proposed method agree well with those obtained from tensile creep tests. Key Words:Residual life evaluation, Indentation creep, Creep constitutive law