PSI - Issue 36

Odarka Prokhorenko et al. / Procedia Structural Integrity 36 (2022) 254–261 8 Odarka Prokhorenko , Serhii Hainutdinov, Volodymyr Prokhorenko et al. / Structural Integrity Procedia 00 (2021) 000 – 000 ~(0.6218...0.9278)e-3, as shown in Fig. 6 (d). This completes the analysis of the kinetics of phase processes in the considered nodes of the plate on the weld axis. 261

(b)

(a )

(d)

(c)

Fig. 6. Kinetics of (a) ferrite; (b) austenite; (c) bainite; (d) martensite at nodes on weld axis during welding by «Fr_ 8 2» scheme .

4. Conclusions The more irregular is the kinetics of temperature at different points of the weld and HAZ during the movement of the welding heating source, the more uneven will be the distribution of structural phases in the weld and in the longitudinal sections of HAZ in the residual state. The reason for the localization of the maximum proportions distribution of structural phases in the weld and HAZ of the welded joint is the unfavorable kinetics of temperature in the vicinity of the back-step welded sections joining locations (two places for the "Fr_72" scheme and five places for the "Fr_82" scheme). The maximum values of the phase proportions do not coincide with the joining locations of the welded sections. A quantitative analysis of the proportion distribution of the upper bainite (up to ~36%) on the weld axis during welding by "Fr_72" and "Fr_82" technological schemes, allows to conclude that it is inexpedient to use such welding schemes due to lower mechanical characteristics on the accomplished weld, caused by the negative effect of the upper bainite, which is formed in significant proportions during welding. Peak values of the martensite phase proportions on the weld axis, in the vicinity of the welded sections joining, is ~2.3 times greater for "Fr_72" welding scheme than for the "Fr_82" scheme. In longitudinal sections, at distances 10, 15 and 20 mm from the weld axis, the martensite phase distribution is practically uniform and quantitatively the same. References Goldak, J. A., and Akhlagi, M., 2005. Computational Welding Mechanics. U.S.,Springer. Haievskyi, O. A., Kvasnytskyi, V. F., Haievskyi, V. O, Zvorykin, C. O., 2020. Analysis of the influence of system welding coordination on the quality level of joints. Eastern-European journal of enterprise technologies 5/1(107), 98- 109. https://doi.org/10.15587/1729 4061.2020.204364 Koistinen, D.P., Marburger, R.E., 1959. A general equation prescribing the extent of the austenite-martensite transformation in pure iron-carbon alloys and plain carbon steels. Acta Metallurgies 7, 59-60. Leblond, J.B., Fortunier, R., Bergheau, J.M., 2000. A numerical model for multiple phase transformations in steels during thermal processes. Journal of Shanghai Jiaotong University (Science) 5(1), 213-220. Makhnenko, V.I., 1976. Raschetnyye issledovaniya kinetiki svarochnykh napryazheniy i deformatsiy . Kiyev: «Naukova dumka». Prokhorenko, V. M., Prokhorenko, D. V., Zvorykin, C. O., Hainutdinov, S. F., 2019. Kinetics of strains during single-pass fusion welding of a symmetrical butt joint. Technological Systems 3 (88), 87 – 98. https://doi.org/10.29010/88.11 Prokhorenko, V . М., Prokhorenko, D. V., Hainutdinov, S. F., Perepichay, A. A., 2018. Kinetics of temperature and plastic strains during heating a longitudinal edge of a steel band by moving welding heat source. Technological systems 3(84), 63-77. Slyvinskyy, O. A, Chvertko, Y., Bisyk, S., 2019. Effect of welding heat input on heat-affected zone softening in quenched and tempered armor steels. High Temperature Material Processes An International Quarterly of High-Technology Plasma Processes 23(3), 239 – 253. SYSWELD, 2015. Reference manual version 2015. ESI Group.