Comparison between contact and immersion ultrasonic method to evaluate welding residual stresses of dissimilar joints

This paper presents a comparison of contact and immersion waves used to measure residual stresses. The residual stresses are produced due to a dissimilar welding of stainless steel (304) to carbon steel (A106). Longitudinal critically refracted (LCR) wave propagated by 2 MHz contact and immersion ultrasonic transducers is employed to measure the residual stresses. A Finite Element (FE) model of welding process, which is validated by hole-drilling method, is used to verify the ultrasonic results while an acceptable agreement is achieved. The best agreement is observed in the parent material while the maximum difference is measured in the heat affected zone (HAZ). The results show no considerable difference between using contact and immersion transducers in ultrasonic stress measurement of dissimilar joints.

► The main goal is comparison of contact and immersion method in stress measurement.
► Welding process of dissimilar plate and pipe is modeled by finite element analysis.
► Residual stresses are measured by contact and immersion ultrasonic transducers.
► The comparison between ultrasonic and FE results show an acceptable agreement.
► Considerable difference between using contact and immersion method is not observed.