| 摘要 |
PURPOSE:To carry out stable flaw detection while reducing the incidence loss of an ultrasonic wave by transmitting ultrasonic beam from a probe equipped with an ultrasonic nozzle using water as a medium to allow the same to be incident to a turbine rotor and receiving the reflected wave from the internal flaw of the turbine rotor by the probe to carry out flaw detection. CONSTITUTION:The ultrasonic nozzle 16 mounted on a probe 14 is arranged at a desired flaw detecting position. At this time, the ultrasonic nozzle 16 is filled with water in a slightly pressurized state not destructing seal rubber 16a. One or more water nozzle 17 is arranged to the tip of the ultrasonic nozzle 16 and water is injected from the water nozzle 17 to fill the space between the tip of the ultrasonic nozzle 16 and a turbine rotor 6. Ultrasonic beam 22 is allowed to be incident to the turbine rotor 6 from the probe 14 using the water in the ultrasonic nozzle 16 and the water in the seal rubber 16a and the above mentioned space as media. A rotor rotating apparatus 12 is driven in this state to rotate the turbine rotor 6 connected to said apparatus 12 and the entire periphery of the turbine rotor 6 is subjected to flaw detection. |
