Closed cracks can cause the underestimation or overlook by conventional (linear) ultrasonic method, because the ultrasound is transmitted through closed cracks. To solve this problem, we have developed an imaging method, subharmonic phased array for crack evaluation (SPACE), based on subharomonic generation by large-amplitude short-burst-wave input and phased-array imaging algorithm with frequency filtering. Thus far, we have demonstrated in the crack depth measurement in closed fatigue cracks and stress ...
英字タイトル:
Sizing of Closed Cracks Using Subharmonic Phased Array

Phased array ultrasonic testing (PAUT) has performed an important role for plant maintenances. However, many parts of cast austenitic stainless steels are difficult to be inspected by UT owing to their noises from large grains. We have been noticing that depending on the PAUT conditions, (e.g. incident angles and focal depths), the tendency of echoes from defects are different from that of grain noises. Thus we have developed new PAUT system which can analyze the tendency of echoes from comprehensive PA...
英字タイトル:
Sizing Accuracy Improvement of Defects in Cast Austenitic Stainless Steel Using Post Processing Phased Array UT

山本 智 Satoshi YAMAMOTO Non-Member (Times New Roman 10pt) should be about 150 words. Recently, an application target of the phased array ultrasonic testing (PAUT) has been extended. For the inspection of CASS, low frequency (less than 1 MHz) array probe is required. Low frequency array probe are usually constructed by large pitch element. In the case of linear scanning, the low frequency array probe could not obtain enough number of sound beams which construct a precise B-Scope image owing to non-dense arra...
英字タイトル:
Accuracy improvement of the linear scanning phased array UT with a large element array probe