The Paton Welding Journal, 2016, №07



2016 №07 (09)

DOI of Article 10.15407/tpwj2016.07.01

2016 №07 (02)

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The Paton Welding Journal, 2016, #7, 2-7 pages
 

Strengthening phases, structure and properties of low-alloy steel modified welds

V.V. Golovko, L.I. Markashova, O.S. Kushnaryova And V.V. Zhukov

E.O. Paton Electric Welding Institute, NASU 11 Kazimir Malevich Str., 03680, Kiev, Ukraine. E-mail: office@paton.kiev.ua
 
 
Abstract
Effect of dispersoid inoculants (phase inclusions) in form of TiC, SiC and ZrO₂ refractory compounds on kinetics of structural transformations in weld metal of high-strength low-alloy steels was investigated. Effect of the inoculants of different type on displacement of bainite transformation into area of higher temperatures is shown. Electron microscopy is used to analyze the nature of structural-phase changes in formation of bainite structure, i.e. peculiarities of fragmentation, distribution of dislocation density and morphology of carbide phase precipitation. The estimations of specific contribution of all structures and their parameters (phase composition, grain, subgrain and dislocation structures etc.) on carried change of strength characteristics and crack resistance of weld metal at inoculation of disperse phase inclusions were out. The optimum composition was determined for dispersoid inoculants used in welding of high-strength low-alloy steels. They provide for necessary mechanical properties of welded joints, including their crack resistance. 14 Ref., 7 Figures, 4 Tables.
 
Keywords: structure of high-strength steels, welded joints, alloying, phase precipitates, dislocations, strengthening factors, local internal stresses
 
 
 
Received:                02.02.16
Published:               02.08.16
 
 
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