| 摘要 |
PURPOSE:To forecast the life of a turbine rotor, by a method wherein the inner surface of the center hole of the turbine rotor is pretreated by grinding and the brittleness degree and latent crack of the inner surface of the center hole are measured by a non-destructive measuring means and the brittleness degree at the time of the next inspection is estimated from the measured result of the brittleness degree and preliminarily calculated brittleness degree characteristics. CONSTITUTION:A test piece comprising the same material as a turbine rotor main body is heated for a predetermined time and impact is applied to the heated test piece to preliminarily grasp the brittleness degree thereof. An initial brittleness degree is preliminarily calculated from a mill sheet. Next, a non-destructive measuring means of a brittleness degree is determined and the brittleness of a turbine rotor main body wherein the inner surface of the center hole thereof was pretreated by grinding is measured to estimate the shift of a destruction toughness value. Subsequently, the latent crack of the inner surface of the center hole of the turbine rotor main body is measured to determine the size thereof. By estimating the brittleness at the time of the next inspection from the measured result of the brittleness degree and preliminarily calculated brittleness degree characteristics, the life of the turbine rotor can be forecast.
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