Simulation of Focusing Phased Array Ultrasonic in Dissimilar Metal Welds for Detecting the Defects

Phased Array Ultrasonic Testing (PAUT) is one of the most efficient and economic methods for inspecting weld joints. In some industrial applications, Dissimilar Metal Welds (DMW) are used for connecting the austenitic stainless steel pipes to the ferritic steel. Inhomogeneity and anisotropy of DMW causes ultrasonic waves to skew and attenuate. This issue can decrease the defects echo and reduce the probability of detecting them. Therefore, PAUT is used for inspection of DMW due to its ability to steering and focusing the ultrasonic waves. Conventional focusing technique is used for focusing waves in the homogenous and isotropic media. However, this technique can’t be used for focusing wave in DMW. In this paper, the conventional focusing technique developed for focusing ultrasonic waves in inhomogeneous and anisotropic media. Results of ultrasonic waves focused on defect in DMW media by the developed conventional focusing technique are compared and validated by adaptive focusing technique. Simulation results have been shown that developed conventional focusing technique has acceptable accuracy operation for focusing waves in inhomogeneous and anisotropic media such as DMW. In addition, the amplitudes of the defect echoes has increased about 235% , compared to conventional ultrasonic testing which indicates that the waves is correctly focused on defect.