Ultrasonic Total Focusing Imaging of Defects in Anisotropic Austenitic Stainless Steel Weld

The austenitic stainless steel, with excellent corrosion resistance, oxidation resistance and low temperature toughness, has been widely used in petrochemical, machinery, nuclear and many other fields. Due to inhomogeneous and anisotropic characteristics of austenitic steel, distortion occurs during ultrasonic beam propagation, and it is hard to meet the requirement of accuracy during defect detection and safety evaluation process. In this paper, the total focusing method (TFM) was applied to defect detection of anisotropic austenitic steel welds, combined with Dijkstra's path finding algorithm for calculation of ultrasound ray path and propagation time. The results showed that the TFM method could be used on weld inspection, with higher accuracy and smaller location error. The research work provides a feasible technical scheme for defect detection of austenitic steel welds.