International Scientific-Technical and Production Journal
January
2009
# 1
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
Skulsky V.Yu., Tsaryuk A.K. and Moravetsky S.I. Evaluation of
susceptibility of welded joints of heat-resistant chromium
martensitic steel to cracking at heat treatment ..................................... 2
Makhnenko O.V., Muzhichenko A.F. and Seyffarth P.
Application of mathematical modelling in thermal straightening
of shipbuilding panels .......................................................................... 6
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:
I.N.Kutianova, T.K.Vasilenko,
V.F. Orets
PE «Melnik A.M.»
Editor
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
Subscriptions:
$324, 12 issues per year,
postage and packaging included.
Back issues available.
This publication and each of the articles
contained herein are protected by copyright.
Permission to reproduce material contained in
this journal must be obtained in writing from
the Publisher.
Copies of individual articles may be obtained
from the Publisher.
© PWI, International Association «Welding», 2009
All rights reserved.
N.A.Dmitrieva
Electron galley:
Ustinov A.I., Falchenko Yu.V., Ishchenko A.Ya., Kharchenko
G.K., Melnichenko T.V. and Muravejnik A.N. Producing
permanent joints of γ-TiAl based alloys using nanolayered Ti/Al
interlayer by vacuum diffusion welding ................................................. 12
Najdich Yu.V., Sidorenko T.V. and Durov A.V. Brazing of
ferroelectric ceramics in air environment and pure oxygen
atmosphere ........................................................................................ 16
Pismenny A.S., Pentegov I.V., Stemkovsky E.P.,
Shejkovsky D.A., Kislitsyn V.M. and Lavrenyuk A.V. Improved
method for calculating magnetic-pulse welding conditions ................... 18
Chigaryov V.V., Shchetinina V.I., Shchetinin S.V.,
Stepnov K.K., Zavarika N.G. and Fedun V.I. Increase of crack
resistance of shrouded traveling rolls in high-speed hardfacing ............ 22
INDUSTRIAL
Lobanov L.M., Timoshenko A.N. and Goncharov P.V. Arc spot
welding of overlap joints in vertical position ......................................... 26
Knysh V.V., Kuzmenko A.Z. and Solovej A.S. Increase of cyclic
fatigue life of tee welded joints with surface cracks ............................. 29
Ishchenko A.Ya. and Khokholova Yu.A. Evaluation of
mechanical properties of microstructural constituents of
welded joints ...................................................................................... 34
Litvinov A.P. Trends in development of combined and hybrid
welding and cladding technologies ...................................................... 37
BRIEF INFORMATION
Kharlamov M.Yu., Krivtsun I.V., Korzhik V.N., Petrov S.V. and
Demianov A.I. Refined mathematical model of the electric arc
burning in plasmatron with external current-conducting wire ................ 42
New books ......................................................................................... 45
Kuskov Yu.M., Ryabtsev I.A., Demchenko Yu.V.,
Denisenko A.M., Dzhavelidze Z.Z., Kbiltsetsklashvili Kh.N. and
Khutsishvili A.A. Hard-facing bay for repair of hydropower
equipment parts in company «Sakenergoremonti» ............................... 46
News .................................................................................................. 48
NEWS
Branch meeting-conference of «Gazprom» specialists .......................... 49
Developed at PWI ......................................................................... 41, 51
Стр.1
EVALUATION OF SUSCEPTIBILITY OF WELDED JOINTS
OF HEAT-RESISTANT CHROMIUM MARTENSITIC STEEL
TO CRACKING AT HEAT TREATMENT
V.Yu. SKULSKY, A.K. TSARYUK and S.I. MORAVETSKY
E.O. Paton Electric Welding Institute, NASU, Kiev, Ukraine
The mechanisms of cracking of welded joints in tempering used to relieve stresses are conside
welded joints on steel 10Kh9MFB with a homogeneous martensitic structure are insensitive
red. It has been found that
to temper cracking. Formation
of δ-ferrite in the martensitic structure may lead to cracking of the weld metal. Cracks form in tempering in the range
of about 450--550 °C as a result of concentrated deformation within the zone of soft ferrite i nterlayers in development
of secondary hardening of the martensitic matrix. A probable cause of hardening is precip itation of chromium carbide
M7C3.
Keywords: arc welding, martensitic steel, welded joints,
heat treatment, dispersion hardening, soft interlayers, temper
cracking
Manufacture of welded structures from hardening
heat-resistant and high-temperature steels is related
to the need to perform heat treatment of welded joints
for tempering of quenching structures and lowering
of the residual stress level. In some cases temper cracks
can form in the welded joints during heating or soaking
in certain temperature intervals. The risk of cracking
increases at treatment of rigid joints, as well as in the
presence of design stress raisers, lacks-of penetration,
undercuts and extended inner defects in them.
Temper cracks (or reheating cracks) are defects
forming as a result of a non-uniform plastic deformation
under the conditions of high-temperature relaxa
-
tion of inner stresses [1]. The non-uniform nature of
relaxation creep of metal at tempering can be related
to chemical microinhomogeneity (which is charac -
teristic of weld metal) and development of dispersion
hardening of grain bodies at certain temperatures as
a result of precipitation of finely dispersed phases,
namely carbides, intermetallics. Grain strengthening
due to secondary hardening is a factor of «relative
softening» of grain boundary regions. As a result, the
deformation at relieving of inner stresses is concen -
trated in the grain boundary zone. A fast increase of
density of crystalline structure defects at local deformation,
as well as formation of interatomic discontinuities
under the impact of embrittling impurities,
leads to initiation of microdamage in the form of initial
pores [2--4] and to crack propagation. A feature of
temper cracks is their intergranular nature.
A susceptibility to hardening and, therefore, to
formation of cracks at tempering is found in steels
containing strong carbide-forming elements (tita -
nium, vanadium, niobium) and elements strengthening
the solid solution (molybdenum, chromium, which
also belong to carbide-forming elements) [1, 5--9].
Depending on the alloying system, strengthening can
© V.Yu. SKULSKY, A.K. TSARYUK and S.I. MORAVETSKY, 2009
2
be induced in structural and heat-resistant steels by
Cr7C3, Mo2C, V3C4 carbides, in austenitic steels ---by
NbC, TiC carbides, in nickel-based alloys ---- by
intermetallics of Ni3(Al, Ti) type [1, 3, 7, 10, 11].
Lowering of high-temperature ductility in the bound
-
ary zone and crack formation are caused by impurities
of phosphorus, arsenic, antimony, tin and sulphur [1,
5, 12--16]. According to the data of [17], the embrittling
action of such impurities as phosphorus and sul
-
phur is due to weakening of the bonds between the
metal atoms as a result of formation of electronic bonds
on the levels of s-orbitals of metal atoms and p-orbitals
of impurity atoms. Such elements as silicon, manganese,
carbon, aluminium and copper [3, 5, 18] also
increase the temper cracking susceptibility. They,
however, have an indirect influence on embrittlement,
for instance, by enhancing the grain-boundary segregation
of phosphorus (silicon, carbon, manganese)
[5], or ousting carbon from the zone of their clustering
with formation of soft microstructural components
(silicon, aluminium).
In welded joints the metal in the near-weld sections
is more susceptible to cracking, these sections developing
a coarse-grained structure as a result of heating
to subsolidus temperatures and a high degree of hard
-
ening as a consequence of a more complete dissolution
of the carbide precipitates and saturation of γ-solid
solution by carbon and carbide-forming elements. In
the welds cracks can form predominantly in the mi -
crosections, in which the solidification boundaries en
-
riched in liquating impurities, coincide with the secondary
boundaries ---- the austenite grain boundaries.
There is a sufficient number of publications de -
voted to studying the problem of temper brittleness
of low-alloyed pearlitic and bainitic heat-resistant
steels with up to 2--5 % Cr [2, 4--6]. Introduction of
new complex-alloyed martensitic steels with increased
chromium content leads to the need to study the prop
-
erties of their welded joints, including temper crack
sensitivity. Possible predisposition of such steels to
development of processes usually accompanied by
cracking, is associated with the presence of carbide1/2009
Стр.2