Automatic Welding, 2017, №04



2017 №04 (01)

DOI of Article 10.15407/as2017.04.02

2017 №04 (03)

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Avtomaticheskaya Svarka (Automatic Welding), #4, 2017, pp. 11-14
 

Effect of alternating magnetic field on magnetic properties, structure and stressed state of vessel steel welded joints

K.A. Yushchenko¹, A.V. Mats², I.M. Neklyudov², V.I. Sokolenko² and N.A. Chernyak²

¹E.O. Paton Electric Welding Institute, NASU 11 Kazimir Malevich Str., 03680, Kiev, Ukraine. E-mail: office@paton.kiev.ua
²National Science Center Kharkov Institute of Physics and Technology 1 Akademicheskaya Str., 61108, Kharkov, Ukraine. E-mail: vsokol@kipt.kharkov.ua
 
Abstract
Earlier investigations showed that treatment of welded joints of reactor vessel steel 15Kh2NMFA with alternating magnetic field of commercial frequency significantly improves a complex of mechanical properties under conditions of uniaxial tension that is accompanied by decrease of a level of thermal stresses in a weld zone. Aim of the present work is study of the effect of magnetic treatment on magnetic characteristics, structure, level and distribution of residual stresses in the welded joint. Changes of stress-strain state in different areas of the welded joint were evaluated on data of X-ray diffraction and electron-microscopic examinations. It is shown that effect of alternating magnetic field results in decrease of a level of microstresses in a transition layer and balancing of spectrum of these stresses in all area of heat affect. Correlation of changes of initial magnetic susceptibility and microstresses in the transition layer and formation of expressed magnetic texture in the weld central part is noted. The mechanisms of changes of magnetic properties and structure at magnetic treatment of welded joint, which are related with activation of plastic microdisplacements and defect redistribution, were considered. Given method of magnetic treatment can be observed as magnetic tempering, providing rise of homogeneity of stress-strain state of welded joints. This promotes increase of their resistance to nucleation and propagation of cracks. 10 Ref., 1 Table, 3 Figures.
 
Keywords: welded joint, vessel steel, magnetic treatment, structure, internal stresses
 
 
Received:                21.02.17
Published:               17.04.17
 
 
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