| The principle and character of the nondestructive test method for steam turbine rotor steel was reviewed. A kind of nondestructive test method based on chemical etch technique was proposed. The test of mechanical properties, metallography analysis and chemical etch was carried out on lab-charged 30Cr2MoV rotor steels, and then a predicting model for detecting nondestructively the fracture appearance transition temperature (FATT50) of the steels was constructed. Under different condition to etch 30Cr2MoV, the essay find the maximum etch to 30Cr2MoV, and at the same time not to the crystal. The models for predicted temper embrittlement of rotor steels were obtained by multiple linear regression. The result showed that the prediction error of the models obtained by multiple linear regression and genetic programming was within the scatter of ±7℃. The result could be used as the bases in the management work of turbine, including overhaul, life-forecast and abandon.
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