1. (In-service Inspection,ISI)2mm1mm3mm6R7R1mm5 (steam turbine)(stator)(rotor)/(disk rim)(blade root)(MT)(PT)(ET)[1,2](UT) -1- 2. (1)(2)(3)(disk rim, steeple, fir treedovetail)(Stress Corrosion Cracking, SCC)(1)(95%)III[3-5](1) ISteepleSide-Of-the-Groove, SOG(2)IIRimBottom-Of-the-Groove, BOGSteeple(3)IIISteeple III II I 1 3 ( 6R 7R ) (mock-up)(2)72mm4mm1mm(3)5mm1235mm(4)-2- 3. NotchFBH2 3(6R7R ) NotchFBH 36R()7R() 4 -3- 4. AEAMicroplusB-scanRF(encoder)B-scan 0.2mmA-scan5MHz3450mm75mm110mm110mm705MHz(5) 5 B-scan63mm -4- 5. (skew angle) 76770~80K.K. KB-A5MHz/0.25 706dB64~74767(LD=5mm5mm)2mmB-scan11mm5mm(8)A A B EE Notch AA FBHC D EBottom Serration Crack7 67 Top B-scan 6 /7R) ( /6R) B-scan-5- 6. Notch 18Notch8 B-scan ()A-scan () MTMT-6- 7. MTET13mm0.15mm0.3mm2.5mm9L-29 RohmannELOTEST-B12mm2MHz -7- 8. (10)10 11(a)342MHz11(b)(3040)(power roller)1mm-8- 9. 11(a) UNIWEST US-686 2.0 MHz X/Y15/15 dB 183 deg.11(b) ()()3mm6mmB-scan -9- 10. 36R/7R1mm DL=2mm5mm11mmDL=5mm5mm 1. Nondestructive Examination of Steam Turbine Blades: An assessment, Reinhard & Associates, Inc., EPRI CS-3675, Project RP 1266-24, Final Report, Nov. 1984.2. Hussein M. Sadek, Eddy Current Inspection of Steam Turbine Components, Materials Evaluation, Vol. 46, 1988, pp. 442-446.3. Steam Turbine Disk Cracking Experience, EPRI NP-2429-LD, Project 1398-5, Final Report, June 1982.4. G. P. Singh, G. A. Lamping, G. M. Light, M. J. Kolar, S. N. Liu, Nondestructive Examination of Low-pressure Steam Turbine Rotors, Proceedings of the 6th International Conference on NDE in the Nuclear Industry, 1982, pp. 739-749.5. G. P. Singh, R. A. Cervantes, and R. L. Spinks, Ultrasonic NDE Technique for the Examination of Low-pressure Turbine Disk Rims, Materials Evaluation, Vol. 41, No. 13, December 1983, pp. 1511-1516.-10-