Automatic Welding, 2022, №12



2022 №12 (07)

DOI of Article 10.37434/as2022.12.01

2022 №12 (02)

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Avtomaticheskaya Svarka (Automatic Welding), #12, 2022, pp. 3-8

Strengthening of welded structures of 25KHGNMT steel by pulsed barrier discharge treatment

L.M. Lobanov¹, O.M. Berdnikova¹, M.O. Pashchyn¹, O.L. Mykhoduj¹, O.S. Kushnaryova¹, T.G. Solomiychuk¹, V.I. Kryvyi²

¹E.O. Paton Electric Welding Institute of the NAS of Ukraine. 11 Kazymyr Malevych Str., 03150, Kyiv, Ukraine. E-mail: office@paton.kiev.ua
²Scientific and Production Association Praktika, 15, Metalistiv Str., 03057, Kyiv, Ukraine

The development of high-tech industries stimulates the growth of requirements for metal of welded structures, a complex of their basic and special properties. The use of pulsed electric currents, plasma currents, pulsed electromagnetic fields and their combined effects to improve the mechanical characteristics of metals and alloys is relevant in connection with the need in replacing traditional energy-intensive technologies of treatment of welded structures with more progressive. The use of a pulsed barrier discharge (PBD) in the metal treatment, which generates low-temperature plasma on the surface of the treated metal is a new approach to optimizing mechanical properties of high-strength steels for welded structures, which is based on electrophysical processes. In the work, strengthening of 25KhGNMT steel as a result of PBD action on its surface was investigated. PBD treatment of steel took place in a discharge device at an increment rate of voltage ≈3·1011 V/s. The effect of PBD treatment period on Vickers hardness value (HV) of test specimens was investigated. Studies of the structure of 25KhGNMT steel were carried out by the method of transmission electron microscopy to reveal its changes as a result of PBD action. It was found that values of HV after PBD treatment increase from 420 to 505 kg/mm2, accompanied by a general increase in dislocation density and dispersion of microstructure, which can positively affect the mechanical characteristics of 25KhGNMT steel for welded structures operating under dynamic loads. 13 Ref., 2 Tabl., 7 Fig.
Keywords: pulsed barrier discharge, surface treatment, low-temperature plasma, structural steel, Vickers hardness, electron microscopy, microstructure, substructure, dislocation density, strengthening, mechanical characteristics


Received: 02.08.2022

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