Automatic Welding, 2022, №03



2022 №03 (01)

DOI of Article 10.37434/as2022.03.02

2022 №03 (03)

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Avtomaticheskaya Svarka (Automatic Welding), #1, 2022, pp. 19-25

Influence of welding modes on decarburization in the haz of R91 steel in welded joints of dissimilar steels after high-temperature tempering

M.O. Nimko, V.Yu. Skulskii, A.R. Gavrik, I.G. Osipenko

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

Carbon migration from the lower-alloyed to the higher-alloyed steel takes place in welded joints of dissimilar steels, as a result of the diff erence in carbon chemical potential after tempering and in high-temperature service. Decarburization in the HAZ near-weld zone of the lower-alloyed steel can lead to formation of service defects and subsequent failure. From mass transfer theory it is known that in polycrystalline bodies the diff usion of interstitial elements, in particular carbon, occurs most rapidly along the grain boundaries. Theoretically, reduction of carbon diff usion can be achieved by increasing the grain dimensions in the HAZ near-weld zone that will lead to reduction of the overall grain boundary area per a unit of volume in this zone. This work is a study of the infl uence of the angle of electrode inclination and welding current at deposition of austenitic metal on R91 steel on the width of the decarburized layer, forming at subsequent tempering at the temperature of 700 and 760 C. It is shown that the resultant decarburized layer becomes narrower with increase of the angle of electrode inclination and deposition current. 18 Ref., 10 Fig.
Ключові слова: carbon diff usion, dissimilar steel joint, HAZ, decarburized interlayer, grain boundaries


Received: 17.01.2022

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