| 摘要 |
PROBLEM TO BE SOLVED: To estimate the material deterioration degree of an article to be measured by using a specified formula by measuring the sonic velocity of a use material as the index reflecting the change of material deterioration, that is, the change of metal texture and a chemical compsn. SOLUTION: The surface of the desired part of an article to be measured is ground over a range of about 10×10mm, and a measuring element to be an ultrasonic oscillator/detector is brought into contact with the ground surface. The measuring element is connected to an ultrasonic oscillator and a waveform measuring instrument and has constitution capable of measuring and recording the oscillation of ultrasonic waves and the waveform of the reflected waves from a material. When the time exciting ultrasonic waves in the article to be measured is set to (to), the time detecting an echo is set to (te) and the thickness of a measuring region is set to W, sonic velocity Vs is calculated according to formula. It is necessary to form a master curve wherein the relation between the deterioration degree and sonic velocity of a heat- resistant material is investigated in relation to the heat-resistant material constituting the article to be measured. The deterioration degree of the characteristics of the heat-resistant material can be calculated on the basis of the observed sonic velocity and the master curve. |
