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2020 №05 (08) DOI of Article
10.37434/as2020.05.01
2020 №05 (02)

Automatic Welding 2020 #05
Avtomaticheskaya Svarka (Automatic Welding), #5, 2020, pp. 3-9

Structure and crack resistance of special steels with 0.25...0.31 % carbon under the conditions of simulation of thermal cycles of welding

O.M. Berdnikova, V.A. Kostin, V.D. Pozdnyakov, O.A. Gaivoronskii, T.O. Alekseenko, I.I. Akekseenko
E.O. Paton Electric Welding Institute of NAS of Ukraine, 11 Kazymyr Malevich Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua

The impact of thermodeformational cycle of welding on structural-phase transformations in the HAZ metal of armour steel of 30Kh2NMF type with different carbon content (0.25; 0.29 and 0.31%) was studied. At the next stage, structural changes in model samples – simulators with 0.31 carbon at different cooling rates (3.8; 12.5 and 21 C/s) and nature of their fracture after bend testing were studied. As a result of the performed studies, it was established that the structure ensuring the optimum level of strength and fracture toughness, forms when low cooling rates are used (below 3.8 C/s). 13 Ref., 3 Tabl., 6 Fig.
Keywords: special high-strength steel, thermodeformational welding cycle, thermokinetic transformation diagrams, heat-affected zone, microstructure, fracture mode, crack resistance

Received: 24.02.2020

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