The Paton Welding Journal, 2021, №04



2021 №04 (07)

DOI of Article 10.37434/tpwj2021.04.01

2021 №04 (02)

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The Paton Welding Journal, 2021, #4, 2-8 pages

Physico-mechanical properties of welded joints of high-strength steel with the yield strength of 690‒1300 MPa

O.M. Berdnikova

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

Abstract
The work is devoted to determination of regularities of influence of features of structural-phase composition (grain, subgrain, dislocation structures, etc.) of metal of welded joints of high-strength steels of different strength class on their mechanical characteristics and crack resistance by determining structural criteria providing the necessary set of these properties. The structure and properties of welded joints of high-strength steels with the yield strength from 690 to 1300 MPa was investigated depending on the rates of cooling and welding, welds alloying, heat treatment conditions and welding methods (mechanized arc, laser, hybrid laser-arc welding): structural low-carbon steels of bainitic-ferritic and bainitic-martensitic type; high-carbon ferritic-pearlitic type; alloy medium-carbon steels of martensitic-bainitic type of a special purpose. The correlation between structural parameters and such a set of properties as strength, fracture toughness, level of localized deformation and local inner stresses in the metal of welded joints was established. It was shown that in compliance with certain ratios of structural-phase components, the characteristics of dislocation and subgrain structure are decisive for providing strength and crack resistance of welded joint metal of high-strength steels. The indices of the level of localized deformation in the metal of welded joints of high-strength steels were obtained and it was found how structural components affect crack resistance of the metal. In order to provide the service reliability of structures in the creation of science-intensive and promising technologies for welding of high-strength steels on the basis of material experimental and theoretical studies, structural criteria were determined to provide the required set of mechanical properties and crack resistance of the mentioned joints. 12 Ref., 4 Figures.
Keywords: high-strength steels, welded joints, structural-phase composition, substructure, dislocation density, mechanical properties, local inner stresses, localized deformation, crack resistance

Received 23.02.2021

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Suggested Citation

O.M. Berdnikova (2021) Physico-mechanical properties of welded joints of high-strength steel with the yield strength of 690‒1300 MPa. The Paton Welding J., 04, 2-8.

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