The Paton Welding Journal, 2013, №09



2013 №09 (02)

2013 №09 (04)

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The Paton Welding Journal, 2013, #9, 18-23 pages

ELECTRODYNAMIC STRAIGHTENING OF ELEMENTS OF SHEET WELDED STRUCTURES

L.M. LOBANOV, N.A. PASHCHIN and O.L. MIKHODUJ

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


Abstract
The need for regulation of residual distortion caused by welding in sheet metal structures is one of the urgent problems of modern welding fabrication. A promising approach featuring a low power consumption and not requiring metal-intensive equipment, is development of the method to lower welded joint distortion, based on application of electrodynamic treatment of welded joints by pulsed current. The objective of this work is investigation of effectiveness of electrodynamic straightening of elements of sheet welded structures. Influence of pulsed current electrodynamic treatment on lowering of residual form change in elements of sheet welded plates from AMg6 aluminium alloy and 30KhGSA and St3 structural steels was studied. Capacitive storage was used to generate pulsed current at electrodynamic treatment, and treatment was performed at contact interaction of working electrode, mounted in a flat inductor, with weld surface. A special fixture was used for electrodynamic treatment, allowing treatment of plates to be performed both in unrestrained state and with their pre-bending. Influence of successive application of current pulses at electrodynamic treatment and direction of plate treatment were studied. Results of the performed research showed that welded joint straightening by electrodynamic treatment allows an essential lowering of values of longitudinal and transverse deflection of welded plates from structural steels and aluminium alloy. It is established that the sequence of electrodynamic treatment performance in the direction «from middle to edges» is the most effective for reducing plate distortion, induced by welding. Application of «reverse» bending of plates initiating stresses on weld surface on the level of material yield point, in combination with electrodynamic treatment, allows practically eliminating residual distortion of longitudinal welded joints of AMg6 alloy and significantly lowering it in joints of structural steels. 12 Ref., 2 Tables, 3 Figures.


Keywords: aluminium alloys, structural steels, longitudinal deflection, transverse deflection, electrodynamic treatment, preliminary outward bending, weld, automatic welding, coated electrode welding


Received:                04.06.13
Published:               28.09.13


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