The Paton Welding Journal, 2020, №05



2020 №05 (08)

DOI of Article 10.37434/tpwj2020.05.01

2020 №05 (02)

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The Paton Welding Journal, 2020, #5, 2-8 pages
 

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. Poznyakov, O.A. Gaivoronskii, T.O. Alekseenko and I.I. Alekseenko

E.O. Paton Electric Welding Institute of the NAS of Ukraine 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua

Abstract
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 their fracture mode 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 Tables, 6 Figures.
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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