Sectorial Scan PAUT Combined with TOFD, a Robust Weld Inspection Technique in Lieu of RT

摘要

Over the last two decades, several studies and practical trials have shown the value of combining automated pulse-echo UT and TOFD techniques to replace radiography for the manufacturing inspection of welded joints in various industries. Although widely used in pipeline NDT, the "zone-discrimination technique" has several limitations and practical issues. Combining sectorial scan phased array and TOFD techniques will result in a more robust and flexible inspection technique, but increases the performance requirements on phased array UT data acquisition hardware and software. This paper will show how recently developed portable phased array hardware and state-of-the-art software can adequately support this improved concept for volumetric weld inspection. Various aspects of the hardware and software specification will be discussed, highlighting the potential benefit of enhanced performance on the final inspection results. The presented practical examples will also include considerations about phased array and TOFD probe design, selection and generation of focal laws, and analysis of inspection results.