PSI - Issue 20

Eduard Gorkunov et al. / Procedia Structural Integrity 20 (2019) 4–8 Eduard Gorkunov et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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4. Conclusion The paper has presented the results of studying the effect of the number of zero-to-tension loading cycles with a magnitude approximately corresponding to conventional yield strength on the magnetic parameters of the 08G2B hot-rolled pipe steel, including longitudinal and transverse magnetostriction. It has been found that the rms values of magnetic Barkhausen noise voltage vary uniquely with the increasing number of cycles; this enables this parameter to be used for the development of methods for estimating the condition of the metal of structures working under cyclic loading. The presence of extrema in the region of positive fields on the field dependences of differential magnetic permeability, the value of the fields at which they are formed, and the magnitude of the extrema allow one to evaluate the strain accumulated in a cyclically loaded product. It has been demonstrated that, as the number of zero-to-tension cycles grows, the field dependences of the longitudinal ( ║ ) and transverse ( ┴ ) magnetostrictions of the steel behave the same way as under static compression; namely, for the dependence ║ ( Н ) it is the positive portion that increases with the number of cycles, whereas the transverse dependence has an increasing negative portion. Acknowledgements The work was performed within the framework of the state assignment, theme АААА - А18 -118020790148-1. The equipment of the “Plastometriya” center of collective sharing was used in the study. References Abukus, S., 1977. Magnetics Studies of Residual Stress in Iron and Steel Induced by Uniaxial Deformation . Japanese Journal of Applied Physics 16, 1161 – 1170. Bulte, D.P., and Langman, R.A., 2002. Origins of magneto-mechanical effect. Journal of Magnetism and Magnetic Materials 251, 229 – 243. Gorkunov, E.S., Smirnov, S.V., and Rodionova, S.S., 2003. Influence of plastic deformation at hydrostatic pressure on damage and magnetic characteristics of low-carbon steel 3sp. Fizicheskaya mezomekhanika 6, 101 – 108. Gorkunov, E.S., Smirnov, S.V., Zadvorkin S.M., Vichuzhanin, D.I., and Mitropolskaya, S.Yu., 2004. Effect of shear strain and accumulated damage on magnetic properties of steel in torsion. Fizicheskaya mezomekhanika 7, 311 – 314. Gorkunov, E.S., Povolotskaya, A.M, Zadvorkin, S.M., and Putilova, E.A., 2017. Comparative Analysis of the Magnetic Characteristics of Plastically Deformed Metal in Different Zones of a Welded Pipe under Elastic Deformation . Russian Journal of Nondestructive Testing 53, 636 – 643. Mirchev. Y., Chukachev, P., and Mihovski. M., 2018. Methods for evaluation of mechanical stress condition of materials. Matec Web of Conferences 145, 05008. Nichipuruk, A.P., Rozenfel'd, E.V., Ogneva, M.S., Stashkov, A.N. and Korolev, A.V., 2014. An experimental method for evaluating the critical fields of moving domain boundaries in plastically tension-deformed low-carbon wires. Russian Journal of Nondestructive Testing 50, 566 – 573.