Comparison of ultrasonic image features with echodynamic curves for defect classification and characterization

Abstract

Ultrasonic array imaging and multi-probe pulse echo inspection are two common ultrasonic techniques used for defect detection, classification and characterization in non-destructive evaluation. Compared to multi-probe pulse echo inspection, ultrasonic array imaging offers some advantages such as higher resolution images and the requirement to obtain fewer measurements. However, it is also limited by a lack of industry-approved inspection procedures and standards. In this paper, several artificial planar and volumetric weld defects of different orientations and locations embedded in 60 mm thick welded ferritic test specimens were measured using both ultrasonic arrays and multiple single crystal probes. The resultant TFM images and echodynamic curves for each defect were compared and the results demonstrate the correlations between TFM image features and echodynamic curve characteristics. Combining the analysis of multi-probe pulse echo inspection data and ultrasonic array images offers better classification and characterization of defects. These findings benefit the further development of industrial ultrasonic array inspection procedures and encourage the uptake of TFM technology within industry.