Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy
The effect of the gaseous medium composition during thermo-chemical treatment (TCT) on the mechanical properties and acoustic parameters of Zr-1%Nb zirconium alloy was studied. It is shown that TCT in oxygen-nitrogen contained gaseous media significantly increases the surface hardness and does not w...
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Національний науковий центр «Харківський фізико-технічний інститут» НАН України
2022
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| Цитувати: | Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy / V.S. Trush, M.M. Pylypenko, P.I. Stoev, S.M. Lavrys, T.M. Kravchyshyn, O.H. Luk’yanenko, M.A. Tikhonovsky // Problems of Atomic Science and Technology. — 2022. — № 4. — С. 55-60. — Бібліогр.: 28 назв. — англ. |
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Trush, V.S. Pylypenko, M.M. Stoev, P.I. Lavrys, S.M. Kravchyshyn, T.M. Luk’yanenko, O.H. Tikhonovsky, M.A. 2023-12-05T09:55:21Z 2023-12-05T09:55:21Z 2022 Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy / V.S. Trush, M.M. Pylypenko, P.I. Stoev, S.M. Lavrys, T.M. Kravchyshyn, O.H. Luk’yanenko, M.A. Tikhonovsky // Problems of Atomic Science and Technology. — 2022. — № 4. — С. 55-60. — Бібліогр.: 28 назв. — англ. 1562-6016 DOI: https://doi.org/10.46813/2022-140-055 https://nasplib.isofts.kiev.ua/handle/123456789/195409 669.296:621.785.062 The effect of the gaseous medium composition during thermo-chemical treatment (TCT) on the mechanical properties and acoustic parameters of Zr-1%Nb zirconium alloy was studied. It is shown that TCT in oxygen-nitrogen contained gaseous media significantly increases the surface hardness and does not worsen the mechanical characteristics (including their plasticity) of zirconium alloy which is used as a material for case of fuel nuclear rod. It is established that TCT in different mediums also influences on acoustic parameters of the Zr-1%Nb alloy. Noticeable changes in the acoustic parameters observed at the initial stage of deformation are associated with the features of the destruction of a thin film formed on the zirconium alloy surface after TCT. Наведено дані щодо впливу складу газового середовища, в якому проводили хіміко-термічну обробку (ХТО), на механічні властивості та акустичні параметри зразків із сплаву цирконію Zr-1%Nb. Показано, що ХТО за вибраними режимами в кисневмісному, азотовмісному та азотокисневмісному газових середовищах суттєво збільшує твердість поверхневого шару зразків сплаву цирконію та не погіршує механічні характеристики зразків твельних оболонок, у тому числі їх пластичність. Показано, що за впливом середовища ХТО на характеристики сплаву акустичні параметри виявилися більш інформативними порівняно з механічними властивостями. Зроблено припущення, що помітні зміни акустичних параметрів, що спостерігаються на початковій стадії деформування, пов’язані з особливостями руйнування тонкої плівки, що утворюється на поверхні трубки в результаті ХТО. en Національний науковий центр «Харківський фізико-технічний інститут» НАН України Вопросы атомной науки и техники Physics of radiation damages and effects in solids Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy Механічні та акустичні характеристики оксидованого, азотованого та оксинітрованого цирконієвого сплаву Zr-1%Nb Article published earlier |
| institution |
Digital Library of Periodicals of National Academy of Sciences of Ukraine |
| collection |
DSpace DC |
| title |
Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy |
| spellingShingle |
Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy Trush, V.S. Pylypenko, M.M. Stoev, P.I. Lavrys, S.M. Kravchyshyn, T.M. Luk’yanenko, O.H. Tikhonovsky, M.A. Physics of radiation damages and effects in solids |
| title_short |
Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy |
| title_full |
Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy |
| title_fullStr |
Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy |
| title_full_unstemmed |
Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy |
| title_sort |
mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided zr-1%nb zirconium alloy |
| author |
Trush, V.S. Pylypenko, M.M. Stoev, P.I. Lavrys, S.M. Kravchyshyn, T.M. Luk’yanenko, O.H. Tikhonovsky, M.A. |
| author_facet |
Trush, V.S. Pylypenko, M.M. Stoev, P.I. Lavrys, S.M. Kravchyshyn, T.M. Luk’yanenko, O.H. Tikhonovsky, M.A. |
| topic |
Physics of radiation damages and effects in solids |
| topic_facet |
Physics of radiation damages and effects in solids |
| publishDate |
2022 |
| language |
English |
| container_title |
Вопросы атомной науки и техники |
| publisher |
Національний науковий центр «Харківський фізико-технічний інститут» НАН України |
| format |
Article |
| title_alt |
Механічні та акустичні характеристики оксидованого, азотованого та оксинітрованого цирконієвого сплаву Zr-1%Nb |
| description |
The effect of the gaseous medium composition during thermo-chemical treatment (TCT) on the mechanical properties and acoustic parameters of Zr-1%Nb zirconium alloy was studied. It is shown that TCT in oxygen-nitrogen contained gaseous media significantly increases the surface hardness and does not worsen the mechanical characteristics (including their plasticity) of zirconium alloy which is used as a material for case of fuel nuclear rod. It is established that TCT in different mediums also influences on acoustic parameters of the Zr-1%Nb alloy. Noticeable changes in the acoustic parameters observed at the initial stage of deformation are associated with the features of the destruction of a thin film formed on the zirconium alloy surface after TCT.
Наведено дані щодо впливу складу газового середовища, в якому проводили хіміко-термічну обробку (ХТО), на механічні властивості та акустичні параметри зразків із сплаву цирконію Zr-1%Nb. Показано, що ХТО за вибраними режимами в кисневмісному, азотовмісному та азотокисневмісному газових середовищах суттєво збільшує твердість поверхневого шару зразків сплаву цирконію та не погіршує механічні характеристики зразків твельних оболонок, у тому числі їх пластичність. Показано, що за впливом середовища ХТО на характеристики сплаву акустичні параметри виявилися більш інформативними порівняно з механічними властивостями. Зроблено припущення, що помітні зміни акустичних параметрів, що спостерігаються на початковій стадії деформування, пов’язані з особливостями руйнування тонкої плівки, що утворюється на поверхні трубки в результаті ХТО.
|
| issn |
1562-6016 |
| url |
https://nasplib.isofts.kiev.ua/handle/123456789/195409 |
| citation_txt |
Mechanical and acoustic characteristics of oxidized, nitrided and oxynitrided Zr-1%Nb zirconium alloy / V.S. Trush, M.M. Pylypenko, P.I. Stoev, S.M. Lavrys, T.M. Kravchyshyn, O.H. Luk’yanenko, M.A. Tikhonovsky // Problems of Atomic Science and Technology. — 2022. — № 4. — С. 55-60. — Бібліогр.: 28 назв. — англ. |
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ISSN 1562-6016. ВАНТ. 2022. №4(140) 55
https://doi.org/10.46813/2022-140-055
UDC 669.296:621.785.062
MECHANICAL AND ACOUSTIC CHARACTERISTICS OF OXIDIZED,
NITRIDED AND OXYNITRIDED Zr-1%Nb ZIRCONIUM ALLOY
V.S. Trush1, М.М. Pylypenko2, P.I. Stoev2, S.M. Lavrys1,
T.M. Kravchyshyn1, O.H. Luk’yanenko1, M.A. Tikhonovsky2
1Karpenko Physico-Mechanical Institute of the NAS of Ukraine, Lviv, Ukraine;
2National Science Center “Kharkov Institute of Physics and Technology”, Kharkiv, Ukraine
E-mail: trushvasyl@gmail.com
The effect of the gaseous medium composition during thermo-chemical treatment (TCT) on the mechanical
properties and acoustic parameters of Zr-1%Nb zirconium alloy was studied. It is shown that TCT in oxygen-
nitrogen contained gaseous media significantly increases the surface hardness and does not worsen the mechanical
characteristics (including their plasticity) of zirconium alloy which is used as a material for case of fuel nuclear rod.
It is established that TCT in different mediums also influences on acoustic parameters of the Zr-1%Nb alloy.
Noticeable changes in the acoustic parameters observed at the initial stage of deformation are associated with the
features of the destruction of a thin film formed on the zirconium alloy surface after TCT.
INTRODUCTION
Zirconium alloys are one of the main structural
materials for core products and fuel elements of nuclear
power reactors [1, 2]. They are widely used in nuclear
power engineering due to a unique complex of
properties: low neutron capture cross-section, high
corrosion resistance, high melting point, and good
mechanical properties. Zirconium alloys are widely
used for the production of parts for nuclear reactors:
fuel cladding and structural components of the fuel
assembly (guide thimbles, central tube, rigid angles,
channel pipes).
For nuclear safety, increased requirements are
needed for the fuel rod elements of nuclear reactors. The
most important components of fuel rod elements are
cladding tubes, which provide the necessary mechanical
strength and dimensional stability of the structure,
protect nuclear fuel and distribution products from the
action of the coolant.
Cladding tubes are operated in difficult conditions
while being exposed to temperature, radiation, corrosive
environment and mechanical stress. Outside, they
undergo corrosion upon contact with a coolant with a
temperature of up to 380 °C, and from the inside –
corrosion under the action of moisture, hydrogen,
fluorine, iodine, caesium and other elements released
from the fuel during the operation of fuel rod elements.
Cladding tubes are also constantly under the influence
of mechanical stress from the weight of fuel pellets and
their expansion during operation [1, 2]. The material
and design of a fuel rod element have to provide reliable
operation for a long time under extremely difficult
operating conditions. Therefore, high requirements are
needed for the materials of fuel rod cladding in terms of
strength, ductility and creep resistance [3, 4].
Zr-1%Nb zirconium alloy is used as a material for
fuel rod element cladding, successfully operating in
pressurized water-cooled reactors at a temperature of
300 ºС. During operation in a reactor, damage
accumulates in fuel rod cladding leading to structure
and property change under the influence of a whole set
of external and internal factors. Sometimes this leads to
the destruction of the fuel rod cladding. The critical
processes that limit the service life of the material in the
reactor are water corrosion and hydrogenation [5–13].
In order to reduce the negative impact of these
processes, research is currently underway to create new
and improve existing zirconium alloys that can work
reliably for a long time in reactor conditions at a
temperature of 400 °C and above. In this regard, new
methods are being developed for applying protective
coatings and modifying surface zirconium and its alloys.
The main objectives of surface modification of cladding
tubes are to strengthen the surface layers to reduce wear
of the tubes under the influence of cavitation and
friction processes, as well as to slow down the
formation of hydrides.
A promising method for the purposeful formation of
the phase-structural state of the surface layer of metal is
thermo-chemical treatment (TCT), in particular, the
method of controlled thermodiffusion saturation of
surface layers with oxygen and nitrogen, developed at
the Karpenko Physico-Mechanical Institute of the NAS
of Ukraine (Lviv).
Thermodiffusion saturation provides the formation
of hardened near-surface layers for various functional
purposes on both zirconium and titanium [14–19]. An
important feature of this method is the possibility of
treatment of long and complex products, such as tubes.
The efficiency of TCT depends on the correct choice of
treatment parameters: temperature, time and pressure.
These parameters allow controlling the size and
properties of the surface modified layer after TCT. To
substantiate the expediency of using TCT, it is
necessary to conduct comparative tests of samples in the
initial state and after TCT.
The purpose of the work is to study the influence of
the composition of the medium during TCT on the
mechanical and acoustic characteristics of fuel rod
cladding Ukrainian-made Zr-1%Nb zirconium alloy.
mailto:trushvasyl@gmail.com
56 ISSN 1562-6016. ВАНТ. 2022. №4(140)
EXPERIMENTAL PROCEDURES
Ukrainian fabricated Zr-1%Nb zirconium alloy was
used in this research. The principal technological
schemes for the fabrication of Zr-1%Nb zirconium alloy
for nuclear reactors and the production of fuel rod
claddings are detailed and shown in [20–22]. A feature
of this alloy was the use of calcium-thermal and iodide
zirconium as a base with additives of pipe production
waste, taken in a weight ratio of 60, 30, and 10%,
respectively. The chemical composition of the Zr-1%Nb
alloy after two vacuum arc remelting is given in Table 1
[20–22].
Table 1
Chemical composition of Zr-1%Nb alloy ingots
Element content, wt.%
О2 N2 C Nb Si Fe
0.095 0.005 0.005 1.0 0.004 0.014
For TCT was used special equipment developed at
the Karpenko Physical-Mechanical Institute of the NAS
of Ukraine. Thermodiffusion saturation of the zirconium
alloy was carried out in oxygen-, nitrogen- and
combined nitrogen-oxygen-containing gaseous media.
The treatment regimens are following:
– Oxygen-containing media (R1 – T = 580 °С, τ = 3 h,
P = 0.133 Ра; R2 – T = 580 °С, τ = 0.5 h, P = 1.33
Ра + T = 580 °С, τ = 2.5 h, P = 1.33·10-2 Ра);
– Nitrogen-containing media (R3 – T = 580 °С, τ = 10 h;
R4 – T = 650 °С, τ = 10 h);
– Combined nitrogen-oxygen-containing gaseous media
(R5 – Т = 650 °С, = 5 h, with cooling in an
oxygen-containing environment).
The tensile mechanical characteristics and
microhardness were determined and to explain the
change in material properties metallography and
structure-sensitive method and acoustic emission were
used [23–25].
For studies, ring samples with dimensions
9.13х0.67х2.8 mm were cut from cladding tubes made
of Zr-1%Nb alloy (Fig. 1,a). Samples before tests were
mechanically polished and ultrasonic cleaned.
а
b
Fig. 1. Ring samples (a) and device for the mechanical
test (b)
Surface and matrix hardening before and after TCT
of zirconium alloy was determined by PMT-3M device
with 0.49 N loads on indenter. To measure
microhardness, we have used a Vikers' diamond
indenter in the form of a pyramid with a square basis
and an angle between opposite faces at the vertex equal
to 136°.
During mechanical tests, the samples were stretched
in the transverse direction on a 1958 U10-1 universal
testing machine using special grippers (see Fig. 1,b) at a
strain rate of 0.17 mm/min (2·10-4 s-1) at room
temperature.
Acoustic emission (AE) parameters (activity, total
sum of pulses, and amplitude distribution of acoustic
emission signals) were recorded synchronously with the
mechanical characteristics using the acoustic complex
M400 [26, 27], the analysis of which made it possible to
determine the features of deformation of the sample
material and the surface layer at different stages of
deformation. A TsTS-19 piezoceramic transducer with a
resonant frequency of 180 kHz was used as an AE
sensor. The sensor was fixed to the test sample through
a special waveguide, which served as one of the
mounting supports for the sample in the test fixture
(Fig. 2). To determine the characteristics of the state of
surfaces, non-destructive testing can also be used [28].
Fig. 2. Devices for testing ring sample for mechanical
and AE test: 1 – capture; 2 – mounting unit of the ring
sample; 3 – cone waveguide; 4 – sensor AE;
5 – frame device
The collection, processing and analysis of the
results, which included information on acoustic
emission and deformation parameters, was carried out
using a computer and specially developed data
processing programs.
RESULTS AND THEIR DISCUSSION
The dissolution of penetration elements (oxygen,
nitrogen) in metals (including zirconium alloys) is
associated with a distortion of the crystal lattice,
resulting in a significant increase in hardness.
Therefore, an increase in surface microhardness and
depth of the hardened layer indicates that, as a result of
TCT, the near-surface layer was enriched with
penetration elements (Table 2).
Table 3 shows the mechanical characteristics of
Zr1%-Nb alloy ring samples after different TCT
regimes. TCT of samples in oxygen, nitrogen and a
combined oxygen-nitrogen media (according to regime
R1–R5) does not lead to an increase in tensile and yield
strength compared to the initial state (R0) (see Table 3).
ISSN 1562-6016. ВАНТ. 2022. №4(140) 57
There is a tendency for a slight fluctuation in the values
of deformation towards the failure after the TCT.
Table 2
The results of the hardness testing
of Zr-1%Nb alloy after TCT
Regime
Surface
microhardness
HV, GPa
Matrix
microhardness
HV, GPa
Depth of the
hardened layer
l, µm
R0 2.60±0.25 1.70±0.15 15…19
R1 3.10±0.25 1.70±0.15 19…24
R2 2.75±0.20 1.70±0.15 22…27
R3 3.20±0.15 1.70±0.15 32…37
R4 3.15±0.15 1.70±0.15 34…39
R5 5.20±0.40 1.70±0.15 38…43
Table 3
Mechanical characteristics of Zr-1%Nb alloy
samples in the initial state and after TCT
in various gaseous media
Regime
Tensile strength,
MPa
Yield strength,
MPa
Elongation,
%
R0 465.07.5 387.53.6 29.61.8
R1 448.90.5 370.30.5 35.80.1
R2 459.09.5 390.00.8 33.70.5
R3 447.62.5 374. 84.0 30.41.5
R4 432.57.5 368. 05.5 27.30.2
R5 432.12.5 355.92.0 26.80.2
To analyse the obtained results, histograms were
constructed, which made it possible to visually compare
the effect of TCT regimes on mechanical parameter
(ultimate strength, yield strength, and deformation to
failure). The initial mechanical characteristics were used
for fuel rod samples in the state of supply (Fig. 3).
The nature of the deformation curves (Fig. 4) was
evaluated, which made it possible to estimate the
magnitude of the stress in the sample in any area of
deformation and showed the features of the deformation
processes in the areas of strengthening and necking.
Fig. 4 shows the deformation curves of the tested
zirconium alloy samples in the initial state and after
different regimes of TCT.
Fig. 3. Mechanical properties of Zr-1%Nb samples after
different regimes of TCT
а
b
Fig. 4. Deformation curves (a, b) of Zr-1%Nb alloy
samples in the initial state (R0) and after TCT
in various gaseous media (R1–R5)
According to durometric and mechanical tests, it
was established that TCT in different media leads to the
formation of a hardened surface layer. However, the
TCT regimes have little effect on the mechanical
characteristics (elongation, tensile and yield strength)
compared to the Zr-1%Nb alloy in the initial state. That
is, the TCT modes used in this research do not
significantly change the characteristics of the
macroscopic deformation of fuel rod elements of
claddings made of Zr-1%Nb alloy. The observed
fluctuations in mechanical properties are in the range of
scatter during testing.
Fig. 5 shows the dependence of the sum of AE
pulses on the elongation during the deformation of
Zr-1%Nb alloy ring samples.
Fig. 5. Dependence of the sum of AE pulses on
elongation during deformation of Zr-1%Nb alloy ring
samples
The results of the experimental data show that the
sum of registered AE pulses depends on the
58 ISSN 1562-6016. ВАНТ. 2022. №4(140)
temperature, time exposure and medium of the TCT.
From the above data, the following conclusions:
– TCT by different modes leads to an increase in
the sum of AE pulses in samples compared to untreated
Zi-1%Nb alloy samples;
– TCT of samples in a nitrogen-containing (R4)
and combined nitrogen-oxygen gaseous media (R5)
leads to a significant difference in the magnitude and
nature of the accumulation of AE signals compared to
untreated samples.
Fig. 6 shows the amplitude distribution of AE
signals when the samples are deformed to failure. An
analysis of the data of this distribution showed that the
nature of amplitude distribution of the untreated and
treated samples of fuel rod claddings tested in this work
does not change.
a b
Fig. 6. Amplitude distribution of AE signals during deformation of Zr-1%Nb alloy ring samples in the initial state
(R0) and after TCT: a – TCT in an oxygen-containing media (R1, R2);
b – TCT in a nitrogen-containing media (R3, R4) and combined nitrogen-oxygen-containing media (R5)
а b
c d
Fig. 7. AE activity and deformation curves of samples after different TCT regimes:
a – in the initial state (R0); b – R1; c – R4; d – R5
It is obvious that the features of AE that are
observed at the beginning of the deformation of the
Zr-1%Nb alloy samples are associated with the
peculiarity of the behaviour of surface films formed
during TCT. The main contribution to the total sum of
AE pulses of the samples comes from the failure of
surface hardened film. On the surface of untreated
samples, the film that forms during the manufacture of
ISSN 1562-6016. ВАНТ. 2022. №4(140) 59
the fuel cladding is not very strengthened and is
characterized by a weak adhesion strength to the metal.
Therefore, even at low loads. the film begins to break
down and peel off, TCT at a temperature of 650 °C in
nitrogen and combined nitrogen-oxygen gaseous media
forms a strengthened film with strengthened adhesion,
so we register more signals and a wider range of
deformations.
To analyse features of acoustic emission, let us
consider the dependences of the AE activity for samples
of the initial state (R0) and after TCT according to
different regimes in different media. Additionally, strain
curves for these samples (R1, R4, R5) were
superimposed on the AE activity dependence graph
(Fig. 7).
The assumption about the role surface layer is
confirmed by an increase in the sum of registered AE
pulses for samples after TCT at a higher temperature
and treatment time. Another confirmation of this
assumption is the analysis of the fractography of the
destroyed samples of the zirconium alloy. On Fig. 8
shows the fracture surface of Zr-1%Nb zirconium alloy
ring samples in the initial state (R0) and after TCT in a
combined nitrogen-oxygen media at 650 °C (R5).
Analysis of the obtained data showed:
– registration of AE signals begins immediately after
the start of loading;
– the maxima on the activity curves fall in the stress
region. below the yield strength;
– AE activity in the initial state samples during
deformation is low and it increases after in TCT treated
samples;
– the generation of AE signals in the treated samples
continues up to higher strains;
– after the yield strength, the AE activity drops
sharply and remains low until the failure of the material.
Therefore, it can be assumed that, in addition to the
gradient layer, an oxide or nitride layer is formed on the
surface of the tube during TCT, which is an additional
source of AE.
An analysis of the obtained AE parameters showed
that the difference in TCT regimes leads to more
noticeable changes in the acoustic characteristics than in
the mechanical characteristics.
а b
Fig. 8. Fracture surface of zirconium alloy samples in the initial state R0 (a) and after TCT by regime R5 (b)
CONCLUSIONS
1. TCT in oxygen-, nitrogen-, combined oxygen-
nitrogen-containing gaseous media significantly
increases the surface hardness and depth of the hardened
layer Zr-1%Nb alloy samples and does not worsen the
mechanical properties of fuel rod samples, including
their plasticity.
2. When determining the impact exerted by various
time-temperature regimes and the gaseous media of
TCT on the properties of the alloy, the acoustic
characteristics turned out to be more informative
compared to the mechanical ones. Noticeable changes in
the acoustic parameters of the samples of the Zr-1%Nb
alloy, observed at the beginning of deformation. are
associated with the features of the failure of a thin film
formed on the surface as a result of TCT.
3. An increase in the surface hardness and depth
near-surface hardened gradient layer and the
preservation of mechanical properties after the TCT
allows us to expect higher efficiency in lowering the
rate of hydrogenation and oxidation of fuel rod cladding
made of Zr-1%Nb zirconium alloy.
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Article received 02.08.2022
МЕХАНІЧНІ ТА АКУСТИЧНІ ХАРАКТЕРИСТИКИ ОКСИДОВАНОГО, АЗОТОВАНОГО
ТА ОКСИНІТРОВАНОГО ЦИРКОНІЄВОГО СПЛАВУ Zr-1%Nb
В.С. Труш, М.М. Пилипенко, П.І. Стоєв, С.М. Лаврись, Т.М. Кравчишин,
О.Г. Лук’яненко, М.А. Тихоновський
Наведено дані щодо впливу складу газового середовища, в якому проводили хіміко-термічну обробку
(ХТО), на механічні властивості та акустичні параметри зразків із сплаву цирконію Zr-1%Nb. Показано, що
ХТО за вибраними режимами в кисневмісному, азотовмісному та азотокисневмісному газових середовищах
суттєво збільшує твердість поверхневого шару зразків сплаву цирконію та не погіршує механічні
характеристики зразків твельних оболонок, у тому числі їх пластичність. Показано, що за впливом
середовища ХТО на характеристики сплаву акустичні параметри виявилися більш інформативними
порівняно з механічними властивостями. Зроблено припущення, що помітні зміни акустичних параметрів,
що спостерігаються на початковій стадії деформування, пов’язані з особливостями руйнування тонкої
плівки, що утворюється на поверхні трубки в результаті ХТО.
https://link.springer.com/journal/11041
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