APPARATUS AND METHOD FOR MEASURING DEGREE OF EMBRITTLEMENT OF CENTER HOLE OF HIGH AND MEDIUM PRESSURE STEAM TURBINE

摘要

PROBLEM TO BE SOLVED: To provide an embrittlement degree measuring apparatus and method capable of nondestructively measuring the secular embrittlement degree of the center hole of a high and medium pressure steam turbine in periodical inspection. SOLUTION: An embrittlement degree measuring apparatus 1 is equipped with an operation stick 50 having a lever opening part 50a provided to the under surface in the vicinity of the leading end part thereof. An electrolytic cell 10 applying electrolytic action to the inner surface of a center hole 200 through the stick opening part 50a in such a state that the operation stick 50 is inserted in the center hole 200 to output the relationship between potential and a current is provided in the operation stick 50 at the position corresponding to the stick opening part 50a. A polarization curve measuring device 52 for measuring the polarizing curve of the inner surface of the center hole 200 on the basis of the relationship between potential and a current outputted from the electrolytic cell 10 is connected to the electrolytic cell 10. An evaluation device 53 calculating the state of the metal grain boundary of the inner surface of the center hole 200 of a turbine on the basis of the measured polarization curve to calculate an embrittlement degree on the basis of the state of the metal grain boundary is connected to the polarization curve measuring device 52.