INSPECTING METHOD OF METALLIC MEMBER

PURPOSE:To improve the defect detecting accuracy of a center hole by adding internal pressure to the center hole of a rotor shaft, and inspecting the center hole by using jointly an acoustic emission method and the conventional inspecting method. CONSTITUTION:An acoustic emission method (AE method) being a dynamic nondestructive inspecting method is applied to a defect detection of a center hole of a rotor shaft. As for the AE measuring method, a multi-channel AE measuring device 4 which is capable of marking a position is used, and two pieces each of AE detectors 3 are installed to both ends of a rotor shaft 7. Subsequently, internal pressure 3 is added to a center hole 2 of the rotor shaft 7. When a crack exists, stress is concentrated on the tip part of its crack and an elastic deformation is caused, as a result of addition of the internal pressure. Accordingly, the circumference of a position where a defect is generated, which is detected by the AE measuring device is inspected minutely by the conventional inspecting method. In this way, the defect detecting accuracy of the center hole is improved.