International Scientific-Technical and Production Journal
April
2009
# 4
English translation of the monthly «Avtomaticheskaya Svarka» (Automatic Welding) journal published in Russian since 1948
Founders: E.O. Paton Electric Welding Institute of the NAS of Ukraine
International Association «Welding»
Editor-in-Chief B.E.Paton
Editorial board:
Yu.S.Borisov V.F.Khorunov
A.Ya.Ishchenko I.V.Krivtsun
B.V.Khitrovskaya L.M.Lobanov
V.I.Kirian A.A.Mazur
S.I.Kuchuk-Yatsenko
Yu.N.Lankin I.K.Pokhodnya
V.N.Lipodaev V.D.Poznyakov
V.I.Makhnenko K.A.Yushchenko
O.K.Nazarenko A.T.Zelnichenko
I.A.Ryabtsev
Publisher: International Association «Welding»
CONTENTS
SCIENTIFIC AND TECHNICAL
Labur T.M., Taranova T.G., Grigorenko G.M. and Kostin V.A.
Influence of thermal conditions of welding on the features of
crack initiation in the HAZ of joints of aluminium alloys V96
and V96tss .......................................................................................... 2
Ryabtsev I.I., Kondratiev I.A., Kostin V.A., Novikova D.P.,
Bogajchuk I.L. and Babinets A.A. Structure of
phosphorus-containing deposited metal of the tool steel type ............... 8
International editorial council:
N.P.Alyoshin (Russia)
U.Diltey (Germany)
Guan Qiao (China)
D. von Hofe (Germany)
V.I.Lysak (Russia)
N.I.Nikiforov (Russia)
B.E.Paton (Ukraine)
Ya.Pilarczyk (Poland)
P.Seyffarth (Germany)
G.A.Turichin (Russia)
Zhang Yanmin (China)
A.S.Zubchenko (Russia)
Promotion group:
V.N.Lipodaev, V.I.Lokteva
A.T.Zelnichenko (exec. director)
Translators:
A.A.Fomin, O.S.Kurochko,
I.N.Kutianova, T.K.Vasilenko
PE «Melnik A.M.»
Editor
N.A.Dmitrieva
Electron galley:
I.S.Batasheva, T.Yu.Snegiryova
Address:
E.O. Paton Electric Welding Institute,
International Association «Welding»,
11, Bozhenko str., 03680, Kyiv, Ukraine
Tel.: (38044) 287 67 57
Fax: (38044) 528 04 86
E-mail: journal@paton.kiev.ua
http://www.nas.gov.ua/pwj
State Registration Certificate
KV 4790 of 09.01.2001
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© PWI, International Association «Welding», 2009
Nosov D.G. and Razmyshlyaev A.D. Effectiveness of
application of combined magnetic fields in submerged-arc
welding ............................................................................................... 16
Alapati R. and Dwivedi D.K. Microstructure and hardness of
Al--Cu alloy (A2218) welded joints produced by GTAW .......................... 21
Pashchenko V.N. Effect of the composition of plasma air-gas
mixture on parameters of the plasmatron jet ........................................ 27
INDUSTRIAL
Tsybulkin G.A. Control of manipulation robot force action .................... 32
Ilyushenko V.M., Butakov G.A., Ganchuk A.V.,
Ostapchenko V.A. and Goryajnov N.A. Comparative tests of
welding-technological properties of inverter and thyristor
power sources .................................................................................... 34
Reisgen U. and Olschok S. Laser-submerged arc hybrid
welding ............................................................................................... 38
Dzykovich V.I. Effect of the centrifugal thermal spraying
process on properties of spherical tungsten carbide particles .............. 43
BRIEF INFORMATION
Murashov A.P., Demianov I.A., Grishchenko A.P.,
Burlachenko A.N. and Vigilyanskaya N.V. Application of
protective extension in thermal spraying of quasi-crystalline
coatings ............................................................................................. 46
News .................................................................................................. 48
NEWS
Ukrainian-Belarussian Meeting-Presentation of the Technology
of Live Tissue Welding ........................................................................ 49
Developed at PWI ............................................................................... 15
Стр.1
INFLUENCE OF THERMAL CONDITIONS OF WELDING
ON THE FEATURES OF CRACK INITIATION IN THE HAZ
OF JOINTS OF ALUMINIUM ALLOYS V96 AND V96tss
T.M. LABUR, T.G. TARANOVA, G.M. GRIGORENKO and V.A. KOSTIN
E.O. Paton Electric Welding Institute, NASU, Kiev, Ukraine
The influence of thermal impact in nonconsumable electrode and electron beam welding on the features of cracking in
different sections of the HAZ of high-strength complex-alloyed aluminium alloys V96 and V96tss at off-center tension
has been analyzed. It is shown that the used temperature-time parameters of the welding mode change the volume fraction
of particles contained in the alloy, their dimensions, shape and morphology of inclusion location on the boundary between
the grains have an essential influence on the local stressed state in the HAZ metal and determine the associated mechanism
of fracture site initiation.
Keywords: high-strength aluminium alloys, welding,
nonconsumable electrode, electron beam, thermal impact, structure,
heat-affected zone, off-center tension, crack initiation,
fracture
Development of aircraft construction is inseparably
linked with application of new structural materials of
an improved composition and mechanical properties,
one of which is V96 alloy of Al--Zn--Mg--Cu alloying
system. It was highly appreciated by specialists as a
material allowing structure weight to be reduced without
decreasing its rigidity, thus making it attractive
for flying vehicle manufacture [1]. On the other hand,
welded joints of this alloy are characterized by unsatisfactory
ductile properties and low resistance to cold
cracking in the HAZ of welded joints in fusion welding,
which is associated with running of irreversible
physico-chemical processes, accompanying the thermal
cycle of fusion welding. The welded joint HAZ
develops six characteristic structural sections, differing
by grain and boundary dimensions, phase and inclusion
composition [2--5]. Formation of final structures
and physico-mechanical properties of the HAZ
metal depend on decomposition kinetics of metastable
phases and are determined by heat input into the used
welding process [1].
V96 alloy mechanical properties are improved by
adding scandium, which has a high (1814 K) melting
temperature and minimum (3.05 N/m3) specific
weight [6--8]. Dispersed particles of Al3Sc phase form
not as a result of special strengthening treatment, but
are a product of high-temperature decomposition of
oversaturated solid solution of scandium in aluminium
at melt solidification. Al3Sc particles are coherent with
the matrix, they are uniformly distributed in the grain
bulk and preserve their stability at comparatively high
temperature, and, thus, stabilize the structure and
suppress recrystallization, which runs in the metal.
The main factor, explaining the unique influence of
scandium on the structure and properties of aluminium
and aluminium alloys, is the dimensional-structural
similarity of crystalline lattices of aluminium (4.405)
© T.M. LABUR, T.G. TARANOVA, G.M. GRIGORENKO and V.A. KOSTIN, 2009
2
and Al3Sc phase (4.407). Owing to such a similarity,
Al3Sc particles formed at initial solidification are effective
grain nuclei, thus ensuring a maximum refinement
of the cast grains (down to the dendrite cell
size).
The mechanism of decomposition of aluminium
solid solution, formed at weld metal solidification, is
also determined by the principle of the above dimensional-structural
similarity, namely the decomposition
products (Al3Sc particles) precipitate by the homogeneous
mechanism. They feature a high density and
short distance between the particles, respectively.
Here, the strengthening and anti-recrystallization impact
of scandium compared to other transition metals
is noted.
To determine the causes for lowering of ductility
of V96 alloy welded joints (wt.%: 2.3 Mg, 2.1 Cu,
8.1 Zn, 0.2 Zr), it is necessary to study the influence
of thermal conditions of welding on the structural
features of different HAZ sections, establish the
mechanism of crack initiation in them, and compare
it with similar sections of V96tss alloy of the same
composition, but with scandium additives (0.3 wt.%).
Presence of the latter in the alloy composition accelerates
solid solution decomposition during thermal operations
and promotes formation of finely-dispersed
particles of intermetallic phases [5], which, being located
in the grain bulk and along grain boundaries,
strengthen the alloy and prevent metal recrystallization
at heating during welding, while mechanical
properties of the alloy are improved [8].
The purpose of this work is determination of the
influence of structural and physical inhomogeneity
found in the welded joint HAZ, on crack initiation
in nonconsumable-electrode (TIG) and electron beam
(EB) welding [5]. Scanning electron microscope JSM840
with «Link-860/500» microanalyzer system (at
accelerating voltage of 15, 20 and 30 kV) was used
for investigations, allowing determination of the features
of crack initiation and nature of damage of
welded joints in the studied alloys.
4/2009
Стр.2