Anti T-root groove

as a key component of steam turbine rotor

easily generates fatigue cracks at Rchamfer during long-term operation and frequent start-up and shutdown

which usually causes accidents. However

the cracks at this position is difficult to be detected. To solve this problem

an ultrasonic pulse reflection method is adopted to detect the cracks at R-chamfer of the anti T-root groove. First of all

the principle of the ultrasonic testing with A-mode pulse reflection method is introduced. Then

by taking the anti T-root groove of rotor of a steam turbine as the test specimen

artificial simulated cracks with four depths are prefabricated by wire cutting method in endwall chamfer(F1 area) and outsourcing chamfer(F2 area). Finally

the three waveforms

including the transverse wave

longitudinal wave and surface wave

are used to detect the cracks. The results show that

the transverse wave of A-type pulse can effectively detect the deep crack with depth larger than 0.2 mm in the root groove of anti-T type at R-chamfer. Additionally

the problems that should be noted during the detection are also presented.