Automatic Welding, 2016, №06



2016 №06 (17)

DOI of Article 10.15407/as2016.06.18

2016 №06 (19)

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Avtomaticheskaya Svarka (Automatic Welding), #6, 2016, pp. 114-123

Structure and service properties of hybrid laser-arc welded joints of 14KhGN2MDAFB steel

L.I. Markashova, V.D. Poznyakov, E.N. Berdnikova, S.L. Zhdanov, V.D. Shelyagin And T.A. Alekseenko

E.O. Paton Electric Welding Institute, NASU 11 Kazimir Malevich Str., 03680, Kiev, Ukraine. E-mail: office@paton.kiev.ua


Abstract
The paper represents the results of experimental investigations of peculiarities in formation of structure and phase composition of welded joints from high-strength 14KhGN2MDABF steel at different speeds (v_w = 72, 90 and 110 m/h) of hybrid laser-arc welding. Information received at different structural levels (from grain to dislocation) is used for analytical evaluation of effect of the structural parameters on mechanical properties and fracture toughness of the welded joints depending on modes of laser-arc welding. The investigations of effect of the structural factors on mode of crack formation under conditions of different dynamic strength tests at external bend loading as well as cyclic loading were carried out for evaluation of a complex of welded joint service characteristics. A role of the structural factors in change of level of local internal stresses, i.e. sources of nucleation and propagation of cracks in the welded joint metal, is shown. The optimum technological modes of hybrid laser-arc welding are determined. They provide for the high indices of mechanical properties and crack resistance of metal under service conditions of external loading from point of view of structure and phase composition. 17 Ref., 2 Tables, 10 Figures.

Keywords: high-strength steel, hybrid laser-arc welding, welded joints, structure, phase composition, mechanical properties, fracture toughness, external loading, crack resistance


Received:                05.04.16
Published:               19.07.16


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