The Paton Welding Journal 2004 #06

Poritsky P.V., Prilutsky V.P. and Zamkov V.N.
Effect of a shielding gas on contraction of the tungsten-cathode welding arc.
Considered is the effect of characteristics of a gas atmosphere on the process of contraction of the welding arc in inert gases. Calculations have been made, showing that the degree of contraction of the arc discharge depends upon the thermal-physical characteristics of the gas atmosphere and electron-atom collision processes. Impact of the Ramsauer effect on the arc discharge contraction characteristics has been established.
Ershov A.V. and Bykovsky O.G.
Evaluation of energy transfer to arc discharge anode in inert gases.
System of equations and boundary conditions are considered for calculation of near-anode zone of temperature- and ionization-nonequilibrium plasma of inert gases at the absence of molecular impurities. The effect of non-equilibrium in argon plasma and distribution of energy fluxes on anode between electrons, atoms and ions is shown.
Podola N.V., Rudenko P.M. and Gavrish V.S.
Application of adaptive algorithm for welding quality monitoring in control systems of resistance spot welding machines.
Peculiarities of application of the adaptive algorithm of neuron networks in resistance spot welding control systems based on microcontroller are considered. To simplify the required calculations at preset accuracy of control, the neuron network with input process parameters in relative units is suggested.
Zubchenko A.S., Vasilchenko G.S., Starchenko E.G. and Nosov S.I.
Mechanical properties and fracture toughness of welded joints of a WWER-1000 reactor.
Effect of nickel content in weld metal of steel 15Kh2NMFAA welded joints on their brittle fracture susceptibility has been studied, in particular after radiation exposure. It is shown that mechanical properties of weld metal with nickel content of not more than 1.3 % are not lower that those given in the specification. It is recommended that the design of reactors for brittle fracture resistance should be performed on the basis of fracture toughness of welded joints, using a standard curve.
Zadery B.A., Kotenko S.S., Marinchenko A.E., Polishchuk E.P. and Yushchenko K.A.
Effect of annealing temperature on mechanical properties of molybdenum alloy and its welded joints.
Effect of annealing temperature on mechanical properties of base and welded joint metal in molybdenum alloy TsM12 has been studied. It is shown that the character of variations in the ductility characteristics of the weld metal with increase in the preliminary annealing temperature is in good agreement with the character of variations in ductility of the initial material. It has been found that the molybdenum alloy specimens cut at different angles to the rolling direction, as well as specimens made from the weld metal and tested in a temperature range of 20-800 °C, exhibit a three-stage mode of strain hardening.
Krivtsun I.V. and Talerko A.N.
Effect of polarisation of radiation on absorption of laser beam in deep-penetration welding.
Mathematical model has been developed to calculate the space distribution of power of laser radiation absorbed by the surface of a keyhole in deep-penetration laser welding. The model allows for the effect of focusing conditions of the initial beam, wavelength and polarisation of laser radiation on its absorption in the keyhole of an arbitrary shape, as well as multiple reflections of incident radiation from the keyhole surface. The model has shown that polarisation of laser radiation, shape and size of the keyhole have a substantial effect on the distributed and integrated characteristics of absorption of the laser beam by metal welded.
Mikheev P.P., Knysh V.V., Vojtenko O.V. and Brodovoj V.A.
Determination of design S-N curves of welded joints of metal structures currently in service.
A procedure was developed of plotting design S-N curves for the main types of welded joints for in-service structures, using a specially developed software for PC. Obtained design S-N curves of welded joints were compared with the results of fatigue testing of large-scale specimens.
Poznyakov V.D., Kiriakov V.M., Demchenko Yu.V. and Klapatyuk A.V.
Restoration of a crusher movable jaw.
The main approaches are considered which were implemented during restoration of intricate cast metal structures of 35L type steel, in which macro- and microdamages were developed during long-term service. Description of the sequence of process operations during repair of a movable jaw is given.
Kuzmenko V.G. and Guzej V.I.
Hydration of fluxes with a locally-changed chemical composition of grains.
Investigation results on peculiarities of hydration of some grades of welding fluxes, e.g. fused ones and those subjected to preliminary thermal fluorination treatment in a gaseous environment containing HF, are presented. Formation of a low-hydrated layer on the surface of flux grains leads to a dramatic decrease in their susceptibility to moisture absorption. This treatment is especially efficient for fluxes of the basic type and those that have a pumiceous grain structure.
Kisilevsky F.N. and Shapovalov E.V.
Optical generators of light plane for technical vision devices of systems of arc welding automation.
Possible methods of designing light plane optical generators, which may be used in triangulation systems of technical vision of arc welding automation systems are considered, and some comparative characteristics of different kinds of optical generators of the light plane and recommendations on their application with different types of the groove are given.
Lebedev V.A.
Procedure of selection of parameters for pulsed feed of electrode wire.
Some known methods for selection of the main parameters of the mechanism for pulsed feed of electrode wire are analyzed. Procedure for calculation of parameters of pulsed control of electrode metal transfer, based on energy characteristics of mechanized arc and electrode wire feed processes, is considered. It is proved that at selection of the parameters of pulsed motion of electrode wire it is necessary to take into account the limitations determining the stability of the arc process with a pulsed feed.
Tsybulkin G.A.
Evaluation of steepness of the arc static characteristic by the results of indirect measurements.
A method is suggested for assessment of steepness of the static characteristic of an electric arc in consumable electrode welding, which is based on using the results of indirect measurements of some parameters in the welding circuit.
Astakhov E.A.
Effect of detonation coatings on mechanical properties of products.
Effect of coating from VK15 and Al2O3 on fatigue and short-time strength, ductility, impact strength of steel 45, stainless steel 10Kh18N10T and titanium alloy 3V and 3M was established.

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