The Paton Welding Journal 2007 #01

Lankin Yu.N. Automatic control of the MAG welding process with periodic short circuiting of arc gap (Review) 2
A review of publications on automatic control of the process of CO2 welding with short circuiting of the arc gap and control algorithms at each stage of the welding cycle is done.
Kulik V.M. and Savitsky M.M. New procedure for evaluation of cold cracking resistance of hardening steel welded joints 8
A method is suggested for tensile testing of flat specimens of butt joints with decreasing load. Peculiarities of delayed fracture of the joints, depending on the thickness of the steel welded, as well as welding parameters and technique, are considered. It is established that delayed fracture of homogeneous or close to homogeneous butt joints occurs primarily in the weld. The possibility is shown of determining the time of microplastic deformation, stress and delayed fracture energy, as well as time and frequency of microcrack initiation. The procedure can be applied for development of a welding technology.
Nazarenko O.K. and Lanbin V.S. Analog and microprocessor control of the welding electron beam current 14
Results of analog and microprocessor control of welding electron beam current in modern EBW units are discussed. It is experimentally shown that by improving the control algorithms implemented in a built-in microprocessor, it is possible to lower the value of instability of electron beam current to С 1 % in the welding mode and to С 10 % in the mode of low setting-up current (Г 1 mA). Generation of current pulses of the required shape and amplitude is ensured for operation of the system of automatic guidance of the beam to the butt during welding.
Labur T.M., Poklyatsky A.G. and Grinyuk A.A. Improvement of fracture resistance of joints of alloy 1420 produced by nonconsumable-electrode argon-arc welding with forced oscillations of the weld pool 18
Physico-chemical characteristics are compared of the joints of high-strength aluminium alloy 1420 produced by nonconsumable electrode welding in argon by a regular stationary arc and by an arc deflected from the arc vertical axis due to current passing through the filler wire. Values of welded joint strength and bending angle, as well as strength and impact toughness of weld metal, are determined, when batch-produced welding wire SvAMg63 is used. Values of fracture toughness were established, which determine the level of reliability of welded joints in structure service. Features of microstructure of welds and their hardness distribution are analyzed.
Dyadin V.P. Influence of pre-deformation on impact toughness of Charpy sample in fracture 22
An approach is proposed to evaluation of upper shelf impact toughness of Charpy sample depending upon degree of plastic pre-deformation of metal rolled stock. The derived analytical dependencies were analyzed, and main parameters were determined characterizing their change. A simple engineering dependence was proposed, which allowed evaluation of change of the upper shelf impact toughness of a Charpy sample depending upon degree of plastic deformation in fabrication and assembly of the metal structure elements.
Shelyagin V.D., Khaskin V.Yu., Siora A.V., Bernatsky A.V., Goncharenko E.I. and Chizhskaya T.G. Gas-shielded laser and laser-arc welding of steels 27
The effect of argon, carbon dioxide and their mixture on peculiarities of laser and hybrid welding of low-carbon and low-alloy steels was determined. Utilisation of the shielding gas mixture was found to have a positive effect. It is shown that increase of the arc power component in hybrid welding with a laser power of 1–2 kW leads to levelling of the hybrid effect. Stabilisation of the arc and its fixation to the laser beam persists, which allows increasing the welding speed and penetration depth in groove welding.
Kuchuk-Yatsenko S.I., Radko V.P., Kazymov B.I., Zyakhor I.V. and Nikolnikov A.V. Peculiarities of detection of defects in FBW joints on pipes by ultrasonic inspection 31
It is shown that the echo-reflection method involving transducers connected in tandem is an efficient method for ultrasonic inspection of large-diameter thick-walled pipes. For inspection of small-diameter thin-walled pipes, it is expedient to use chord-type TR transducers. Echo signals from defects and interferences in the form of bulges are shown to differ in time of arrival, which allows reliable identification of defects and interferences from the bulges formed as a result of displacement of the weld edges or reinforcement remaining after flash removal.
Bernadsky V.N. and Makovetskaya O.K. Welding fabrication and welding equipment market in modern economy 35
Data are given on the state-of-the-art in welding industry, welding equipment market and its sectors, as well as the key factors affecting their development trends. The role of welding in the present-day economy is shown. In particular, the results of comprehensive evaluation of the contribution of welding to the U.S. and German economy are presented.
Sidorets V.N. and Zhernosekov A.M. Computer simulation of pulsed-arc systems 40
Block-diagrams have been developed for simulation of welding systems including a consumable-electrode arc in MATLAB software package. Simulation allows staging a numerical experiment, solving non-linear differential equations, describing the dynamics of variation of the arc length at electrode melting and of welding current.
Savitsky M.M., Savichenko A.A., Kulik V.M., Lupan A.F., Melnichuk G.M., Chertorylsky L.A., Golub N.A. and Suprunenko V.A. Light-weight welded cylinders for motor transport 43
Design of a welded cylinder for motor transport with a composite skin is described. The possibility of producing light-weight cylinders of different size-types with a specific weight of 0.60–0.65 kg/l is outlined. Guaranteed life of the cylinders is 15–20 years.
News 44
Thesis for a scientific degree 45
Our congratulations 46
Developed at PWI 39

(You are viewing the simplified file contents)