The Paton Welding Journal, 2014, №08



2014 №08 (09)

DOI of Article 10.15407/tpwj2014.08.01

2014 №08 (02)

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The Paton Welding Journal, 2014, #8, 8-14 pages  

EFFECT OF STRESS-STRAIN STATE ON STRUCTURE AND PROPERTIES OF JOINTS IN DIFFUSION WELDING OF DISSIMILAR METALS

V.V. KVASNITSKY¹, V.F. KVASNITSKY², L.I. MARKASHOVA³ and M.V. MATVIENKO²

¹NTUU «Kiev Polytechnic Institute». 37 Pobedy Ave., 03056, Kiev, Ukraine. E-mail: kvas69@urk.net
²Admiral Makarov National Shipbuilding University. 9 Geroev Stalingrada Ave., 54025, Nikolaev, Ukraine. E-mail: welding@nuos.edu.ua
³E.O. Paton Electric Welding Institute, NASU. 11 Bozhenko Str., 03680, Kiev, Ukraine. E-mail: office@paton.kiev.ua
 
 
Abstract
Computer modelling of stress-strain state (SSS) considering change of physical-mechanical properties, structural transformations and creep strains determined that distribution of plastic strains along the joint butt in diffusion welding (DW) of dissimilar materials is non-uniform. The results of mechanical tests of welded joints provide estimation not for different zones of joint but welded joint integral estimation. Aim of the work is determination of effect of SSS on structure and properties of joints in different zones of joint butt at constant temperature of DW and using temperature cycling. Welding of steel 12Kh18N10T and electric steel 10864 (armco-iron) was carried out at constant temperature 1050 °C and two temperature cycles 700-1000 °C. Welded joints were subjected to microstructural and local X-ray microanalysis. Hardness distribution was studied. Significant attention was made to study of fine structure of metal in joint zone and estimation of specific contribution of different structural constituents in total value of yield strength of the welded joints, considering dependence of dislocation density on value and intensity of plastic strain. Carried investigations confirm the results of SSS computer modelling and presence of significant zone of deformation stagnation in DW with constant temperature. It is determined that DW with temperature cycling allows controlling SSS, intensifying processes of volume interaction and providing full strength of 10864 steel joints. 12 Ref., 6 Figures.
 
 
Keywords: diffusion welding, SSS modeling, temperature cycling, structure, plastic strain, mechanical properties, diffusion
 
 
Received:                30.05.14
Published:               28.08.14
 
 
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