| 摘要 |
PURPOSE:To measure nondestructively a remaining service life of a material by comparing a deviation value obtained by comparing an eddy current value from a test piece prior to usage with an eddy current of a material used actually with characteristics between a fracture surface transition temp. and an eddy current of the metallic material. CONSTITUTION:The variation of the eddy current value (shown as an ECT value in the following) is raised with rise of a fracture surface transition temp. Thus, service hours of the metallic material, i.e. the relationship between the variations of the fracture surface transition temp. and the ECT are measured previously, and a probe coil is brought into contact successively with each part of a measuring material 4 to read the ECT value and to allow the read value to correspond to a graph, and the fact that how much service service life is dissipated is measured. Thereby, the remaining service life up to the service limit hour can be measured nondestructively from this result. |
