Performance evaluation of austenitic stainless steel weld defect detection in ultrasonic phased array based on DORT

摘要

For weld in thick walled austenitic stainless steel welds inspection, it is difficult to develop a spatial imaging algorithm for accurate defect detection. The traditional DORT algorithm cannot be used in many commercial ultrasonic phased array detectors, because it requires one element in the probe transmitted a pulse and all elements received echo signals. Many commercial probes can transmit and receive signals using the same number elements. The improved DORT was proposed to suitable for multiple elements transmitting signal and multiple elements receiving echo. The relative performance of the improved DORT algorithm is illustrated using simulated and experimental data. Various manufactured flaws (side-drilled holes of 2 mm diameter) have been machined at several depths of austenitic stainless steel weld block. Despite the high backscattering noise due to multiple scattering, a significant improvement of the detection performances is observed.