PSI - Issue 50

Svetlana Barannikova et al. / Procedia Structural Integrity 50 (2023) 33–39 S. Barannikova, M. Nadezhkin, P. Iskhakova / Structural Integrity Procedia 00 (2023) 000 – 000

38 6

According to the results of this work, the general regularity of the stepwise change in the velocity V of ultrasonic Rayleigh waves with a decrease in temperature consists in the increase at the first stage due to the elastoplastic transition, followed by the decrease at stages III and IV. In particular, the most significant peculiarity is a drop in the velocity of propagation V at stage III, which can serve as a diagnostic sign of the material failure. A noticeable increase in the attenuation coefficient α in stainless steel during the transition from stage III to stage IV occurs owing to the release of the martensitic phase (Talonen et al (2005)). In that regard, the transition from one stage to another can be detected by means of the damage parameter D v , calculated from the measured ultrasonic wave velocity. The course of the dependences D v (  /  f ) and D v (σ/σ B ) is probably related to the formation of structural fragments of different sizes and various levels of internal stresses in the sample volume due to martensitic transformation. The same changes in the deformation mechanism are reflected in the flow curve and the deformation hardening coefficient of the material under consideration (Pelleg (2013)). 4. Summary Ultrasonic measurements have a great potential for studying the kinetics of phase transformations that occur in real time in steels under loading at low temperatures. Both the speed and attenuation of ultrasound are strongly influenced by the test temperature, the degree of deformation, and the microstructure of the phase components of the steel. While the ultrasound velocity is mainly determined by the changes in elastic moduli associated with the degree of distortion of the crystal lattice and the texture of austenitic grains, the attenuation of ultrasound is associated with the size of structural elements and the volume fraction of phases in metastable austenitic stainless steel. Based on the behavior of acoustic characteristics, the stages of plastic flow and damage accumulation before the failure were distinguished in Fe-18% Cr - 10% Ni alloy. A non-destructive testing parameter was proposed for characterization of the transition to a pre- failure stage. Meanwhile, elucidating the specific mechanisms that affect the speed and attenuation of sound in deformable samples at low temperatures requires further research. Acknowledgements This work was supported by the Russian Science Foundation (grant no. 22-29-01608) . References Badidi Bouda, A., Benchaala, A., Alem, K., 2000. Ultrasonic characterization of materials hardness. Ultrasonics 38, 224 – 227. Barannikova S.A., Bochkareva A.V., Lunev A.G., Shlyakhova G.V., Zuev L.B., 2016. Changes in ultrasound velocity in the plastic deformation of high-chromium steel. Steel in Translation 46, 552-557. Barannikova, S.A., Danilov, V.I., Zuev, L.B., 2004. Plastic strain localization in Fe-3%Si single crystals and polycrystals under tension. Technical Physics 49, 1296 – 1300. Gorkunov, E.S., Povolotskaya, A.M., Zadvorkin, S.M., Putilova, E.A., Mushnikov A.N. The Effect of Cyclic Preloading on the Magnetic Behavior of the Hot-rolled 08G2B Steel under Elastic Uniaxial Tension. 2021. Research in Nondestructive Evaluation 32, 276 – 294. Hakan Gür C., Orkun Tuncer, B. 2005. Characterization of microstructural phases of steels by sound velocity measurement. Materials Characterization 55, 160 – 166. Hsu C.-H., Teng, Chen, Y.-J. 2004. Relationship between ultrasonic characteristics and mechanical properties of tempered martensitic stainless steel. Journal of Materials Engineering and Performance 13, 593 – 598. Kobayashi M., 2010. Analysis of deformation localization based on the proposed theory of ultrasonic wave velocity propagation in plastically deformed solids. International Journal of Plasticity 26, 107-125. Kumar, A., Jayakumar, T., Raj, B., Ray, K. K. 2003. Characterization of solutionizing behavior in VT14 titanium alloy using ultrasonic velocity and attenuation measurements. Materials Science and Engineering A 360, 58 – 64. Lunev A.G., Nadezhkin M.V., Barannikova S.A., Zuev L.B., 2018. Acoustic Parameters as Criteria of Localized Deformation in Aluminum Alloys. Acta Physica Polonica A 134, 342-345. Murav'ev V.V., Zuev L.B., Komarov K.L., 1996. Sound Velocity and Structure of Steels and Alloys. Nauka, Novosibirsk, pp. 181. Murav’ev, V.V., Baiteryakov, A.V., Len’kov, S.V., Zakharov, V.A. Correlation of rail structure with the Rayleigh -wave velocity and the coercive force. 2017. Steel in Translation 47, 561 – 563. Murthy, G.V.S., G. Sridhar, G., Kumar, A., Jayakum, T. 2009. Characterization of intermetallic precipitates in a Nimonic alloy by ultrasonic velocity measurements. Materials Characterization 60, 234 – 239. Palanichamy, P., Joseph, A., Jayakumar, T. Raj, B. 1995. Ultrasonic velocity measurements for estimation of grain size in austenitic stainless steel. NDT & E International 28, 179 – 185.