CORRECTION OF FLAW DETECTING CONDITION IN ELECTRON SCANNING TYPE ULTRASONIC FLAW DETECTION APPARATUS

摘要

PURPOSE:To prevent the lowering in flaw detection capacity and flaw position locating accuracy, by performing the correction of an ultrasonic wave incident direction of actual flaw detection scanning on the basis of the difference between the max. angles of refraction of the reflected echo from a reference reflecting source being a material to be inspected having a standard shape and an actual reflected echo. CONSTITUTION:At first, a reflecting source of a material 2 to be inspected coming to a standard is set to a standard shape and a converging condition making the reflected echo from said reflecting source max. is set to a standard. Then, in order to be capable of confirming the reflecting source under a plurality of converging conditions corrected in a focal distance in a predetermined ratio with respect to said standard converging condition, the delay time of the use element of an array type probe is preliminarily calculated at every focal distance system to prepare for a confirming scanning data table. Next, the delay time of the use element of the probe 1 corresponding to a converging condition at every angle of refraction for actual flaw detection is also calculated under the same number of converging conditions corrected only in a focal distance as those at the time of the confirming scanning of the reflecting source to prepare a flaw detection data table. Then, the incident direction of an ultrasonic wave is corrected on the basis of the difference of the max. angles of refraction of the reflected echo from the standard reflecting source being the material to be inspected having the standard shape and an actual reflected echo.