PSI - Issue 16

Yevstakhiy Kryzhanivskyy et al. / Procedia Structural Integrity 16 (2019) 237–244 Yevstakhiy Kryzhanivskyy et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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pass into the weld metal. A decrease in the impact toughness of the weld metal is insignificant compared to the base metal at a temperature of +20 °C and at - 60 ° C.

5. Conclusions

It was found that the impact toughness of the investigated pipe steel of the X70 strength class was high enough. At the same time, the impact toughness of the weld at temperatures of - 40 °C and - 20 ° C was nearly the same as that of the base material. The impact toughness of the W1 and W2 fusion zones at a temperature of - 40 ° C was 1.14 and 1.5 times lower than that of the base metal, respectively. It should be noted that the cutting method of templates, from which specimens were made (either milling or plasma cutting) did not affect the impact strength in the investigated temperature range. It was found that differences in the values of impact toughness in the specimens cut from the central section of the weld and in the zone of thermal influence are caused by their structural state and the localization of deformation processes in Charpy specimens. Arabey, A.B., Pyshmintsev, I.Yu., Struin, A.O., Esiev, T.S., Sivokhin, I.S., 2010. Influence of local brittleness of the weld joint in large-diameter pipe on the structural strength. Steel in Translation 40(9), 785 – 791. Banakhevych, Yu.V., Dragilev, A.V., Kychma, A.O., 2014. Diagnostics of the stress-strain state of multilayer annular welded joints of pipelines. Materials Science 5(2), 217 – 223. Bolzon, G., Rivolta, B., Nykyforchyn, H., Zvirko, O., 2018. Mechanical analysis at different scales of gas pipelines. Engineering Failure Analysis 90, 434 – 439. Gabetta, G., Nykyforchyn, H. M., Lunarska, Е., Zonta, P. P., Tsyrulnyk, O. T., Nikiforov, K., Hredil, M. I ., Petryna, D. Yu., Vuherer, T., 2008. In-service degradation of gas trunk pipeline X52 steel. Materials Science 44 (1), 104 – 115. Gliha, V., Maruschak, P., Yasniy, O., Bischak, R., Samardžić, I., Vuherer, T. , 2011. Fatigue strength of welds in the view of residual stresses, in: Proc. of the 6th Internat. Sci.- Profess. Conf. “Modern Technologies and Processes in the Production of Pressure Equipment, Welded Metal Constructions, and Products” (October 26 – 28, 2011), Slavonski Brod, Croatia, pp. 87 – 97. Kryzhanivs’kyi, E.I., Hrabovs’kyi, R.S., Fedorovych, I.Y., Barna, R.A. , 2015. Evaluation of the kinetics of fracture of elements of a gas pipeline after operation. Materials Science 51(1), 7 – 14. Kryzhanivs'kyi, E.I., Hrabovs'kyi, R.S., Mandryk, O.M., 2013. Estimation of the serviceability of oil and gas pipelines after long-term operation according to the parameters of their defectiveness. Materials Science 49(1), 117 – 123. Matrosov, Yu.I., Nosochenko, A.O., Ganoshenko, I.V., Volodarskii, V.V., 2004. Producing niobium-microalloyed plate steel for gas-line pipe of strength class X70. Metallurgist 48(1-2), 80 – 83. Nykyforchyn, H. M., Student, O.Z., Dzioba, I. R., Stepanyuk, S. M., Markov, A. D., Onyshchak, Ya. D., 2004. Degradation of welded joints of steam pipelines of thermal electric power plants in hydrogenating media. Materials Science 40 (6), 836 – 843. Nykyforchyn, H., Zvirko, O., Tsyrulnyk, O., 2017. Non-destructive diagnostics of hydrogen induced degradation of pipelines steels by electrochemical method, ICF 2017 – 14th International Conference on Fracture, Rhodes, Greece, 1, 596 – 597. Odesskii, P.D., Gurov, S.V., Arsenkin, A.M., Gizatullin, A.B., Bragin, A.A., Titkin, A.A., 2016. Electrowelded straight-seam high-strength pipe for structural use. Steel in Translation 46(7), 510 – 519. Panin, S.V., Maruschak, P.O., Vlasov, I.V., Ovechkin, B.B., 2016. Impact toughness of 12Cr1MoV steel. Part 1 - Influence of temperature on energy and deformation parameters of fracture. Theoretical and Applied Fracture Mechanics 83, 105 – 113. Tabatchikova, T.I., Lepikhin, S.V., Morozova, A.N., Gudnev, N.Z., 2018. Structure and mechanical properties of steel welding joints produced using abrasive waterjet cutting. Physics of Metals and Metallography 119, 691 – 699. Vuherer, T., Maruschak, P. , Samardžić , I., 2012. Behavior of coarse grain heat affected zone (HAZ) during cycle loading. Metalurgija 51(3), 301 – 304. Wilshaw, T.R., Pratt, P.L., 1966. On the plastic deformation of Charpy specimens prior to general yield. Journal of the Mechanics and Physics of Solids 14, 7 – 19. Zvirko, O.I., Tsyrul'nyk, O.T., Voloshyn, V.A., 2012. Characteristics degradation of gas transmission pipeline steel welded joints due to long term operation, 19th European Conference on Fracture: Fracture Mechanics for Durability, Reliability and Safety, ECF 2012, Kazan, Russia, Paper # 142. References