Diagnostics of Dissimilar Weld Joints of Austenitic to Pearlitic Steels by Acoustic Emission: Fid-Bau Portal

Diagnostics of Dissimilar Weld Joints of Austenitic to Pearlitic Steels by Acoustic Emission

Barat, Vera / Marchenkov, Artem / Bardakov, Vladimir / Zghut, Daria / Karpova, Marina / Elizarov, Sergey

Dissimilar welded joints are widely used nowadays in power engineering industry for manufacturing of pipelines and other power equipment elements. Diagnostics of welding defects in these joints by nondestructive testing (NDT) is quite difficult, since high gradients of chemical composition and microstructure reduce the sensitivity of traditional NDT scanning methods. The paper is devoted to the study of the possibility of AE method application for diagnostics of dissimilar welded joints of pearlitic to austenitic steel. The identification of defects lack of penetration and microstructure defects in the form of diffusion interlayers under cyclic tensile loading of flat specimens with welded joints is considered. As a result of the research, it was found that dissimilar welded joints containing defects are characterized by a specific AE signature. It was established that for welded specimens with lack of penetration and diffusion interlayers, the AE activity turned out to be significantly higher than for defect-free ones. Herewith, specimens with diffusion interlayers are characterized by large amplitude values (up to 70–80 dB), and specimens with lack of penetration are characterized by higher AE activity, while the amplitudes of AE hits did not exceed 60–65 dB. The results obtained can be used for determination of diagnostic criteria for detecting defects by AE method and subsequent development of an industrial NDT technique for dissimilar welded joints under study.