Examination of the Inductance Method for Non-Destructive Testing in Structural Metallic Material by Means of the Pancake-type Coil

抄録

We have already proposed the fatigue evaluation method for the metallic material by measuring an inductance of a pancake-type coil using a LCR meter. This method was called the inductance method. This time, we have improved the conventional inductance method by using a low excitation frequency under a dc magnetic field generated by a neodymium (Nd) permanent magnet. The improved method was applied to the evaluation of a fatigue damage accumulation caused by partially pulsating stress in an iron-based structural metallic material (SS400). The new method was able to detect the change of the material condition such as a fatigue damage accumulation in SS400 without receiving the influence of the surface condition of the specimen. In this paper, we report the results of a fatigue damage accumulation evaluation using the new inductance method.