Contents of
the «Paton
Welding
Journal»
¹2, 2000
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Page
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ROLE OF TEMPERATURE IN HYDROGEN-INDUCED
CRACKING OF STRUCTURAL STEELS AND WELDED JOINTS
I.K. POKHODNYA, S.N. STEPANYUK and V.I. SHVACHKO
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2
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| A
procedure is proposed for experimental study of the influence of hydrogen
on mechanical properties of the metal in a broad range of temperatures.
Temperature dependencies of the degree of hydrogen- induced embrittlement
for St.20 and 17KhGNDSM steels in the temperature range of 196+400oC are
determined. It is shown that, alongside the structural state, content and
distribution of hydrogen, stress level and straining rate, temperature is
the main initial factor determining the process of hydrogen embrittlement. |
DETERMINATION OF RESIDUAL
LIFE OF WELDED STRUCTURES WITH CREVICE-TYPE DEFECTS
B.E. ANDREYKIV and M.V. LISHCHINSKA
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8
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| The
calculation model is suggested for investigation of the kinetics of propagation
of fatigue cracks in plates whose material is heterogeneous in mechanical
characteristics and resistance to fatigue fracture. The model is based on
an energy criterion of fatigue fracture of materials. The system of differential
equations has been derived to study the kinetics of growth of fatigue cracks
in heterogeneous plates. Two problems in the determination of a period of
sub-critical growth of a fatigue crack are considered: for a butt-welded
plate and a cruciform welded joint. It is shown that the calculated service
life values are in good agreement with the experimental dat |
APPLICATION OF EXPLOSION ENERGY
FOR IMPROVING RELIABILITY OF WELDED STRUCTURES
V.G. PETUSHKOV
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13
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| The
essence, peculiarities and application fields of a new technology of explosion
treatment of welded joints used to improve reliability and extend life of
metal structures are outlined. Physical mechanism of the process and methods
used for calculation of parameters of explosion loading of different-geometry
weldments are described. Explosion treatment is shown to have a favourable
effect on performance of welded structures and characterized by high productivity
and cost effectiveness. |
EFFECT OF COMPOSITION OF SHIELDING
GASES ON TECHNOLOGICAL CHARACTERISTICS OF ARC DURING NON-CONSUMABLE ELECTRODE
WELDING OF ALUMINIUM ALLOYS
A.Ya. ISHCHENKO, V.P. BUDNIK, A.G. POKLYATSKY and A.A. GRINYUK
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17
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| Experiments
on using neon and its mixtures with argon as a shielding gas in non-consumable
electrode welding are considered. Data are obtained on weld formation, penetration
and also volt-ampere characteristics at direct and alternating currents.
The feasibility of using neon separately or in mixtures of gases for protection
of aluminium alloy welding zone is shown. |
MATHEMATICAL MODELLING OF
THERMAL STATE OF THE BONDING ZONE BETWEEN DISSIMILAR METALS IN GLOW-DISCHARGE
DIFFUSION BONDING
G.P. BOLOTOV, D.I. KOTELNIKOV and A.F. ROGOVOJ
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21
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| The
determinate mathematical model of the ion heating process has been developed
on the basis of analysis of distribution of heat flows within the zone of
contact between dissimilar materials. The model allows temperature of the
bonding zone in bodies of the simplest shape (cylinder, parallelepiped)
to be related to the process parameters and characteristics of the billets.
The error in the calculation of temperature using this model is no more
than 15%. |
IMPROVEMENT OF HEAT AND WEAR
RESISTANCE OF PARTS USING THE METHOD OF THERMAL SPRAYING OF COATINGS OF
CHROMIUM-BASED ALLOYS
V.F. GORBAN
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25
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| Effect
of initial state of chromium-based materials used for thermal spraying on
the properties of coatings is investigated. Interrelation between physical-chemical
properties of coatings and technology of spraying and their effect on service
characteristics of chromium coatings are studied. |
DEVELOPMENT OF THE TECHNOLOGY
FOR THE MANUFACTURE OF ARTILLERY STEEL CARTRIDGES AND BOTTOMS BASED ON
HIGH-TEMPERATURE INDUCTION BRAZING
L.I. BONDARENKO and L.G. PUZRIN
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30
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| Economical
technology based on high-temperature induction brazing for the manufacture
of cartridges and bottoms is suggested. Peculiarities of the technology
are described and characteristics of the brazed joints are given. |
L.I. BONDARENKO and L.G. PUZRIN
ARGON-ARC SURFACE QUENCHING - METHOD FOR HARDENING ARTILLERY BARRELS
L.I. BONDARENKO and L.G. PUZRIN
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33
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| Surface
quenching using concentrated heat sources and travel speed of the source
needed to heat a layer of the required thickness and hardness are considered.
The method, equipment and operational parameters have been developed for
argon-arc surface quenching of the inside surfaces of barrels. Quenching
of the full-scale barrels for the service life tests has been conducted. |
STRUCTURE AND PROPERTIES OF
HYPEREUTECTOID GRAPHITIZED ROLL STEEL AFTER PLASMA HARDENING
S.S. SAMOTUGIN
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35
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| Structure,
hardness, impact toughness and character of fracture of hypereutectoid steel
150KhNM under dynamic loading after plasma hardening, as compared with volumetric
quenching, are investigated. Hardness and impact toughness of steel after
plasma hardening are higher than after volumetric quenching, which is caused
by a highly dispersed martensite-carbide structure formed by plasma treatment.
Fracture of metal of the hardened zone occurs by the mechanism of dispersed
quasi-cleavage, while that of metal after surface micro- and macro-melting
occurs by the mechanism of intercrystalline cleavage. |
ELECTRON BEAM REMELTING OF
OPERATING SURFACE OF EXHAUST VALVES OF AIRCRAFT ENGINES
A.V. BONDAR, M.V. ERYOMIN, S.N. FYODOROV and V.V. SHURUPOV
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39
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| Problems
of repair of flaws of a discontinuity type, which are formed in a layer
of the operating surface of aircraft engine exhaust valve, surfaced with
a flame method, is considered. It is shown that, when using electron beam
treatment with an ellipsoid scanning of beam, the flaws are eliminated in
the deposited surfaces. During electron beam treatment the inner structure
of the deposited layer is changed by refining and reorienting chromium carbides
that increases the microhardness of the working surface. |
APPLICATION OF HEAT SINKS
FOR REDUCTION OF WELDING STRAINS AND STRESSES (Review)
A.I. GEDROVICH and A.B. ZHIDKOV
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41
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| The
possibilities of controlling the strains and stresses in the joints with
artificial heat sink are considered. Classification of welding processes
with heat removal by the technological and physical features, is proposed.
It is found that for up to 3mm thick metal the most effective is the application
of the heat-absorbing pastes and crystalline heat-absorbing rods, and for
3-8mm thick metal it is water cooling. Welding with heat sink should be
regarded as a resources-saving proces |
SELECTION OF EQUIPMENT FOR
MECHANIZED ARC WELDING, SURFACING AND CUTTING
V.A. LEBEDEV and V.F. MOSHKIN
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45
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| The
results of analysis, development and selection of equipment for mechanized
arc welding, surfacing and cutting are considered. It is shown that the
intuitive approach to selection and development of the semi-automatic machines
can lead to non-rational solutions. Methods of system approach are suggested
which allow performance of a highly objective analysis and selection of
the equipment, lowering the probability of taking wrong decisions, also
at the stage of development of new semi-automatic machines. Selection of
modular design using a basic model as a principle allowing development of
semi-automatic machines for various purposes with rational technical and
service parameters, is substantiated. |
PROSPECTS OF UTILIZATION OF
A HARD COMPONENT OF WELDING AEROSOLS
A.A. ENNAN, P.A. IVANCHENKO and G.N. SHIKHALEEVA
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50
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| New
feasibility of utilization of a hard constituent of welding aerosol is described.
Realization of a directed vapour-phase synthesis with producing highly dispersed
powders of a preset composition and a developed surface of a phase contact
will, probably, open up new prospects in the field of creation of materials
of different functional purposes. |
ADVERTISING
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54
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