Contents of
the Paton
Welding
Journal
no.4, 2000
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Page
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PATON B.E.
Space technologies on the threshold of the third millenium
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2
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| Promising
trends in development of space technologies in the next decades are discussed.
Special attention is given to comprehensive material science research. |
ISHCHENKO A.Ya. and
CHAPOR V.O.
Weldability of high-strength alloys of Al-Zn-Mg-(Cu) system (Review)
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5 |
The problems of welding
high-strength alloys of Al-Zn-Mg-(Cu) system are considered. The effect
of chemical composition of alloys and filler material on the weldability
characteristics is analyzed. Causes of defect formation in the welded
joint are described. The problems of weldability and degree of metal weakening
under the action of a thermal cycle depending on the method of welding
are outlined. The further investigations for improving weldability of
alloys of Al-Zn-Mg and Al-Zn-Mg-(Cu) systems are predicted.
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RAZMYSHLYAEV A.D.
Control of bead formation in arc surfacing with strip electrode
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11 |
| Electromagnetic
nature of a defect in the weld bead in the form of a cavity (saddle) formed
in its central portion in DC submerged-arc surfacing using strip electrode
is described. It is suggested that the controlling magnetic fields should
be used to compensate for asymmetry of the magnetic field induced in the
arc zone by the surfacing current flowing through the strip electrode extension. |
BOLOTOV G.P.
Peculiarities of heating parts of limited sizes in glow-discharge diffusion
bonding
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15 |
| Character
of distribution of heat flows in parts of limited sizes in glow-discharge
heating under conditions of diffusion bonding is analysed. The expediency
of using heat-insulating spacers between a part and a clamp is shown. The
precise and approximate solutions of the problem of temperature distribution
in parts, depending upon thermal-physical and geometrical characteristics
of base materials and spacers, are given. |
Pilot Plant for Welding
Consumables today
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19 |
RYABTSEV I.A., KUSKOV
Yu.M. and CHERNYAK Ya.P.
Formation of deposited metal on inclined and vertical surfaces
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22
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| The
effect of surfacing conditions, compositions of charges of flux-cored wires
and fluxes on the formation of a horizontal bead on inclined and vertical
surfaces is experimentally investigated. It is shown that deposition on
such surfaces should be done at a minimum possible amperage and maximum
speed. The best choice for surfacing is the short flux of the AN-15M grade.
The CaCO3-CaF2-TiO2 gas-slag forming system with a component ratio of 3:1:1
provides the best results in the manufacture of self-shielded flux-cored
wire. |
DMITRIK V.V.
Structure of welded joints from low-alloyed heat-resistant Cr-Mo-V pearlitic
steels
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26 |
| Peculiarities
of technology of CO2 automatic welding of structures from heat-resistant
Cr-Mo-V pearlitic steels are considered. Technology is based on the results
of modelling of temperature conditions of the welding process and provides
structure in welded joints which is close to optimum. |
NESTERENKO N.P.
Features of the technology of ultrasonic welding of axially symmetrical
polyethylene containers
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30 |
| The
influence of modes of ultrasonic welding and methods of introducing mechanical
vibrations into the weld zone on the quality of welded joints produced in
sealing of polyethylene containers is considered. It is shown that with
the decrease of the static compression force in the forging stage and of
welding time the welded joint quality is improved at the expense of a more
uniform morphology, absence of defects or texture in the weld zone. A new
welding cycle and the appropriate schematic of dosing the energy of the
introduced mechanical vibrations are proposed. Recommendations are issued
on industrial use of the developed technology. |
LEBEDEV V.A. and
PICHAK V.G. A new approach to design of the electrode wire feed mechanism
P. 33
MIKHED A.M. and
CHERNYSH V.P.
Restoration of the dimensions and properties of cast iron cylindrical
parts by resistance build-up welding with wire
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33
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| The
reduction gear mechanisms of electrode wire feed with roller motors, widely
used in mechanized arc welding equipment, are analyzed. It is shown that
with the increase of the feed roller diameter the values of tractive characteristics
of the mechanism become higher, service life is extended and losses in the
roller feed unit are reduced. A design of the feed roller is given characterized
by a unrestrained mounting of the feeding element on the driving element.
This provides the invariance of the electrode wire feed rate to its diameter,
fast mounting and dismantling of the feed roller in the case of its replacement. |
LUKASH E.S., SHULYM
V.F., GRIGORENKO G.M., SMIYAN O.D. and NEZNAMOVA L.O.
Investigation of the influence of gravity on the composition of coatings
from binary Ag-Cu alloys
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37 |
| The
method of Auger-spectroscopy was used to study the composition of coatings
of Al-Cu alloys produced under different gravity conditions. Some features
of formation of coatings from binary alloys under zero gravity are considered.
The results of metallographic investigations of the structure of the alloys
remnants after evaporation in space and on the Earth are given. |
TUGOLUKOV A.V., KLYUCHNIK
O.N. and BUDYUK E.D.
Structure of martensitic-ferritic steels after surface plasma hardening
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41 |
| Surface
plasma treatment provides a fundamental increase in hardness of steel 20Kh17N2.
This is achieved by varying power of the plasma jet and increasing its concentration.
Metallography revealed three characteristic regions formed as a result of
the plasma jet effect. An increase in the concentration of the heat flow
affecting the sample surface causes a decrease in the hardened and transition
zones, decrease in the amount of carbides in the bulk of the main phases
and reduction in grain size |
BERESTOVOY A.M.
Dimensions of the zone of boiler walls cleaning from solidified pitch
in welding up cracks
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45
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| Sizes
of the zones to be cleaned from pitch for repair welding of cracks formed
during operation in the tank boilers were established experimentally using
simulation samples. The possibility of avoiding overall cleaning of the
tank boiler is proved. The technology for repair welding of cracks eliminating
inflammation of pitch is described. |
KOVALYOV V.D., VASHCHENKO
N.M. and TARASENKO A.G.
Portable mechanical devices for cutting and preparation of pipes for welding
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47
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| Pneumatic
portable metal-cutting machine-tools for cutting pipes of diameter from
20 to 1220 mm in site and pipe facing for welding are described. Portable
pipe cutting and facing machines can be used in manufacture and repair of
pipelines. Unique designs of captive non-detachable pipe cutters are given. |
ADVERTISING
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50
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