The Paton Welding Journal, 2011, №03



2011 №03 (01)

2011 №03 (03)

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The Paton Welding Journal, 2011, #3, 7-12 pages  

FRACTURE SURFACE MORPHOLOGY AT FATIGUE OF MIG-WELDED JOINTS OF AMg6 ALLOY

T.M. LABUR, V.A. SHONIN, T.G. TARANOVA, V.A. KOSTIN, V.S. MASHIN and I.N. KLOCHKOV

E.O. Paton Electric Welding Institute, NASU, Kiev, Ukraine
 
 
Abstract
Results of examination of structure of fracture surface on samples of MIG-welded joints of AMg6 alloy after cyclic tests with loading cycle asymmetry R_s = 0.4 and R_s = -1 are given. Peculiarities of morphology in different fracture regions have been revealed and mechanism of fatigue crack propagation has been established. It is noted that fracture of the welded joints at a microlevel is of a mixed and multi-site nature. High-frequency peening in a narrow AMg6 alloy weld to base metal transition zone using steel strikers provides formation of a smoother geometry of the weld to base metal transition zone and decrease in average values of the stress concentration factor.
 
 
Keywords: arc welding, aluminium alloy, consumable electrode, welded joints, fatigue testing, fracture surface morphology
 
 
Received:                ??.??.??
Published:               28.03.11
 
 
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