ISSN 0036-0295, Russian Metallurgy (Metally), Vol. 2008, No. 5, pp. 391–397. © Pleiades Publishing, Ltd., 2008.
Original Russian Text © O.P. Maksimkin, K.V. Tsai, 2008, published in Metally, 2008, No. 5, pp. 39–47.
Magnetometric Study of the  ' Martensite
Transformationin a Neutron-Irradiated
12Kh18N10T Steel
O. P. Maksimkin and K. V. Tsai
Institute of Nuclear Physics, National Nuclear Center, Republic of Kazakhstan, ul.
Ibragimova 1, Almaty, 480082 Republic of Kazakhstan
Received August 24, 2007
Abstract—The α'-martensite formation in the corrosion-resistant 12Kh18N10T steel unirradiated and irradi18
–2
ated by neutrons (to a dose of 5  10 cm ) is studied by magnetometric measurements during its static
defor-mation in the course of repeated unloading–loading cycles. Kinetic curves are plotted, and the
parameters of the variation in the α'-martensite content in deformed samples are determined for the following
two types of measurements: under loading (dynamic curve of α'-martensite accumulation) and unloading
(static curve). The nature of the complex change in the magnetization of the deformed steel samples during
unloading, which man-ifests itself in detecting the so-called elastic martensite, is discussed.
PACS numbers: 62.20.-x
DOI: 10.1134/S0036029508050066
INTRODUCTION
The results of numerous experiments on the uniaxial
tension of metastable austenitic stainless steels [1–3]
indicate that, from a certain critical strain (stress) to
failure, the α' martensite (deformation-induced martensite), which has ferromagnetic properties, nucleates and
accumulates in samples. The formation of the α '
martensite substantially affects the plastic flow, deformation localization, and the character of the tensile curve
of these steels. Usually, the problem of describ-ing the
laws of the α '-martensite formation and growth in a
deformed sample as a function of the continuously
recorded mechanical deformation characteristics (force
P, linear elongation ∆l) is reduced to finding a static
kinetic relation Mf = f(τ), where Mf is the α'-martensite
content in the sample by time τ. Researchers use a set
of discrete experimental values {M f i , ∆li} obtained
during periodic unloading of a deformed sample followed by recording the residual strain and measuring the
α'-martensite content by X-ray diffraction, Möss-bauer
spectroscopy, dilatometry, or hydrostatic weigh-ing [3–
6]. This is a rather long procedure, which is also
complicated by a change in the state of the sample after
every new stage of determining the α'-martensite content for the next loading. This creates difficulties for
matching the experimental data obtained.
With the experimental technique used in this work [7,
8], we can determine the dynamic (obtained during
deformation) characteristics of α '-martensite accumulation in the material and to reveal a change in the martensite content upon unloading. This technique uses the
ferromagnetic property of the α' martensite that forms
during deformation in an initially paramagnetic austen-
ite matrix. As for magnetometric measurements, this
work resembles the studies of magnetoelastic effects by
constructing the dependence of the magnetic induction
on the mechanical stresses during loading and unloading [9, 10]. The qualitative difference consists in the fact
that the object of inquiry is represented by a ferromagnetic phase whose content can change as a function
of the degree of plastic deformation.
Neutron irradiation is known to strongly affect the
microstructure of austenite and to substantially change
the character of the deformation of steel samples and
the formation of the α' martensite in them [8, 11, 12].
Therefore, the purpose of this work is to study the
kinetics of the deformation martensite formation in an
irradiated austenitic steel.
EXPERIMENTAL
We studied the corrosion-resistant austenitic
12Kh18N10T steel of the following chemical
composi-tion:
Fe
C
Cr
Ni
Ti
Si Mn
P
S
Base 0.12 17.00 10.66 0.50 0.34 1.67 0.032 0.013
The tendency of this steel toward the formation of
deformation martensite is relatively weak: the total α'martensite content upon uniaxial tension to the
ultimate tensile strength in the 12Kh18N10T steel
does not exceed 2–3%.
For mechanical tests, we prepared dumbbell samples with a gage portion 10 mm in length and 1.7 mm
in diameter (Fig. 1). To avoid possible ferrite inclusions, which could affect the purity of the experiment,
391
392
MAKSIMKIN, TSAI
10
∅ 1.7
9
3.5
5
.
∅5
∅3
36.5
Fig. 1. Appearance and dimensions of a cylindrical steel
sample for uniaxial tension.








Fig. 2. Schematic diagram for the setup used for magnetometric measurements: (1) excitation coils, (2) measuring
coils, (3) amplifier, (4) amplifying–measuring
deformed sample, and (6) reference sample.
unit, (5)
we performed the austenitization of the samples at
1050C for 30 min followed by water cooling. After a
preliminary heat treatment, the steel samples were
paramagnetic. To study the effect of irradiation on the
phenomena analyzed in this work, some samples were
subjected to neutron irradiation in the core of a VVR-K
reactor to a dose of 5  1018 cm–2 at a temperature below
100C.
Uniaxial tensile tests were carried out on an FR100/1 tensile-testing machine at 20C and a speed v =
0.5 mm/min. This machine was equipped with a special-purpose device intended for the in situ measurement of the total content of the deformation-induced
ferromagnetic α' martensite from the magnetization of
a deformed cylindrical steel sample during deformation. The device for the magnetometric measurements
contained two excitation coils 1 connected in series and
inductively coupled measuring coils 2 turned on toward
each other (Fig. 2). The excitation coils were powered
from low-frequency public-address amplifier 3, and the
signal from the measuring coils passed to amplifying–
measuring unit 4. Samples 5 and 6, whose gage portions were inside the measuring coils, were measured.
In contrast to reference sample 6, sample 5 was
intended for deformation and was fixed in the grips of
the tensile-testing machine. When sample 5 was subjected to tension, the α' martensite nucleated in its
structure, the magnetization of the steel sample
changed, and a transducer recorded a disbalance signal.
To convert the magnetization into the percentage of the
ferromagnetic phase in the sample, we used a standard
with a known α'-phase content, similar to the technique
in [13]. The sensitivity of determining the magneticphase content in the sample was ~0.05%.
Using this experimental technique, we simultaneously obtained a continuous synchronized stress–
strain diagram and a magnetization curve for a
deformed sample during both loading and unloading.
The magnetometric data represented information on the
relative percentage of the ferromagnetic phase in the
deformed material. 
To obtain points in a static magnetization curve, i.e.,
the curve obtained by magnetometric measurements
during unloading, the sample was periodically
unloaded during deformation and was then again
loaded. Simultaneously, we detected a change in the
magnetometric signal from the deformed sample. The
mechanical tests with step-by-step unloading, repeated
loading, and the recording of magnetometric data were
performed on neutron-irradiated
and unirradiated
12Kh18N10T steel samples. As a result, we obtained
information on the behavior of the steel magnetization
during unloading at various stages of plastic deformation. The measurement data obtained on irradiated samples were compared with the data obtained on unirradiated samples to estimate the effect of irradiation on the
kinetics of the ferromagnetic phase in a deformed sample during unloading. It should be noted that the measurement of the magnetic signal depends substantially
on the sensitivity and design of the magnetometric
transducer. Nevertheless, with the experimental setup,
we were able to reliably estimate the character of the
change in the magnetic response from deformed samples during continuous deformation and unloading.
RESULTS AND DISCUSSION
Figure 3 shows the typical experimental diagrams in
the P–∆l and Mf–∆l coordinates for the 12Kh18N10T
steel that were obtained during loading and during periodic unloading and repeated loading. The elastic part of
deformation is known to be restored after unloading in
the range of the plastic flow in metallic samples. In the
tensile curve presented in the P–∆l coordinates (Fig. 3,
curve 1), this process is described by a linear relationship (dashed lines) with a slope that is equal to the elastic modulus of the material. During the repeated loading of a sample above its yield strength, the tensile
curve continues practically from the point in the curve
from which unloading began if a rather short time has
passed since unloading. With a magnetic transducer, we
simultaneously record a change in the magnetization I,
which is connected with a change in the relative content
of the α' martensite in the sample by the
relation
Mf(∆l) = I(∆l)/I0 (Fig. 3, curve 2). Here, I0 = 1.4B corRUSSIAN METALLURGY (METALLY)
Vol. 2008
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MAGNETOMETRIC STUDY OF THE γ
α' MARTENSITE TRANSFORMATION
responds to the “zero” of the magnetic transducer. During repeated loading, the curve of the change in the
magnetization is close to the corresponding unloading
curve and is slightly shifted up along the ordinate axis.
The table gives the mechanical characteristics of the
deformed 12Kh18N10T steel in the initial state (with-out
irradiation) and after neutron irradiation to a dose of 5 
1018 cm–2 that were calculated from the experimental diagrams. Here, σcrM and δcrM are the critical stress
and strain, respectively, for the appearance of the α '
martensite in the deformed sample, and MBf is the maximum total α'-martensite content, which specifies the
magnetization detected at failure.
Neutron irradiation is known to substantially modify the physicomechanical properties of metallic materials. Most often, it leads to radiation hardening (an
increase in σ0.2 and σu), a decrease in the length of the
uniform deformation section, and a decrease in the total
plasticity [11, 12]. An analysis of the mechanical properties of metastable chromium–nickel steels subjected to
neutron irradiation over a wide dose range demon-strates
that, apart from radiation embrittlement, an irra-diated
material can also behave anomalously during tension.
Specifically, an irradiated steel can exhibit a relatively
high plasticity at a relatively high dose (~1021 cm–2)
[14]. In our case (see table), neutron irra-diation
followed by tension at a temperature of 20C and a rate
of ~10–4 cm–1 results in this deformation behavior of the
12Kh18N10T steel. It exhibits insignif-icant radiation
hardening, and the curve of the irradi-ated steel is
slightly below that for the unirradiated material in the
section of a localized flow in the P– ∆ l stress–strain
diagram. As compared to the unirradiated material, the
plasticity of the steel after irradiation remains almost the
same.
A higher sensitivity to irradiation is observed when
the magnetization, which characterizes the α'-martensite content, is measured in a deformed steel sample.
As follows from the stress–strain diagram, the critical
strain corresponding to the beginning of α'-martensite
formation in the irradiated steel decreases to ~4%. For
comparison, the α ' martensite in the unirradiated
12Kh18N10T steel begins to form in an austenitic
matrix at a critical strain of ~17%. Thus, upon neutron
irradiation, the beginning of α' martensite formation
during tension shifts toward low strains as compared
to the unirradiated material. This effect was observed
ear-lier in unirradiated steels with significant radiation
Mf, arb. units
P, kN
1.6
393
(a)
25
1
20
1.2
2
15
0.8
10
0.4
5
0
1
2
3
4
∆l, mm
0
Mf, arb. units
25
2
20
P, kN
1.6 (b)
1
1.2
15
0.8
10
0.4
0
5
1
2
3
4
∆l, mm
0
Fig. 3. (1) P–∆l tensile curves recorded during step-bystep unloading and repeated loading (dashed lines indicate
unloading–loading cycles) and (2) the corresponding Mf–∆
l magnetization curves for the deformed samples of
12Kh18N10T steel (a) in the austenitized unirradiated
state and (b) after neutron irradiation.
hardening, which was accompanied by the loss of
plas-ticity [15]. It was noted that a localized flow and
neck-ing can begin immediately after the yield
strength because of a decrease in the length of the
uniform elon-gation section. The maximum strains
concentrate in the region of a localized flow, and the α
'-martensite content increases substantially there.
At a constant strain rate, the intensity of the deformation martensite formation can be expressed through
the α'-martensite content ∆Mf accumulated in deformation time ∆τ, ∆Mf/∆l. It was found that, as compared to
the unirradiated material, the intensity of the α'-martensite formation in the neck of the irradiated steel is higher.
In some cases, the total α'-martensite content decreases
in the irradiated samples deformed to failure.
Effect of neutron irradiation on the mechanical properties of austenitic 12Kh18N10T steel
State of the steel
Before irradiation
After irradiation
σ0.2
σu
δu
MPa
274
358
δ
%
722
725
RUSSIAN METALLURGY (METALLY)
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36
Vol. 2008
52
47
No. 5
M
σcr , MPa
539
473
δcr
M
17
4
,%
B
M f, arb. units
15.5
22.5
394
MAKSIMKIN, TSAI
Mf
P
It follows from Fig. 4 that, if the tension of a sample
is broken at any time τi = ∆li/v (which corresponds to a
certain α'-martensite content M f i ), the magnetometer
signal is not constant as the sample is unloaded: it first
increases, passes through a maximum, and decreases to
a certain value. As a result, we have
3
I
Msf = MDf + ∆ M f ,
III
i
2
1
∆l
i
D
is the relative α'-martensite content that corresponds to the full magnetization of the sample in the
loaded state and Msf i is the martensite content that corresponds to the remanent magnetization of the sample
after unloading. Both the sign and value of ∆ M f i (i.e.,
the α' martensite accumulated in time τi) depend on the
degree of the preliminary tension of the steel sample. In
other words, the magnetic response from an unloaded
steel sample containing the α' martensite depends
strongly on the state of the sample before unloading. If
where M f i
II
0
i
0
Fig. 4. (I) Generalized tensile curve and (II, III) the total
content of the ferromagnetic α' martensite in corrosionresistant austenitic 12Kh18N10T steel: (I) P–elongation ∆l
tensile diagram, (II) dynamic magnetization curve for a
steel sample obtained under loading, and (III) static magnetization curve for a steel sample obtained under unloading.
(1, 2, 3) Magnetization of a deformed sample during
unloading at the time when elongation ∆l is <∆lu, ≈∆lu, and
the sample is unloaded at ∆li < ∆lP, where ∆lP corre-
sponds to the ultimate tensile strength and the intense
deformation localization processes in the sample, then
ing to the ultimate tensile strength of the sample.
Msf > MDf
(Fig. 4, curve 1). If ∆li > ∆lP, we have
s
D
M f < M f (Fig. 4, curve 3). If the sample is unloaded
In [12, 15], this effect was related to a significant
decrease in the plasticity and the accompanying embrit- near the ultimate tensile strength, i.e., at ∆lP (Fig. 4,
tlement. In our case, the total α'-martensite content in
curve 2), the remanent magnetization of the sample is
>∆lu, respectively, where ∆lu is the elongation correspond-
both the neck and body of the 12Kh18N10T steel sam-
ples irradiated to a dose of 5  1018 cm–2 (which do not
exhibit a substantial decrease in the plasticity) is higher
than the α'-martensite content in the deformed unirradiated steel. To explain this effect, it is necessary to perform additional studies, which is beyond the scope of
this work.
During periodic unloading of samples at various
stages of their deformation, we detected a nonlinear
relation between the magnetization I of the unloaded
sample and the linearly decreasing load P (see Fig. 3).
The coordinates of the first and last points in the magnetization curve correspond to the beginning and end of
unloading, and the magnetizations at the beginning of
unloading and after complete unloading are significantly different in some cases. A comparison of the
recorded diagrams demonstrates that, although the
unirradiated and irradiated states of the 12Kh18N10T
steel exhibit different tendencies toward α'-martensite
formation, they are characterized by similar effects
recorded by a magnetic transducer during loading–
unloading and repeated loading. To analyze these
results, it is convenient to represent them in the form of
generalized diagrams, i.e., in the form of the superimposed curves plotted in the P–∆l (Fig. 4, curve I) and
Mf–∆l (Fig. 4; curves II, III) coordinates. The magneti-
most often characterized by the relation Msf ≈ MDf. The
whose shapes are close to parabolas with branches
directed down.
“spike” increases with the α'-martensite content in the
material at the time of unloading.
zation curves during unloading represent fragments
lines drawn through points M f and
D
s
M f correspond to
the following two magnetometric curves: dynamic
curve II (it reflects the α'-martensite content in the
loaded sample at various strains) and static curve III
(it characterizes the process of the periodic unloading
of the sample).
The shape of the Mf–∆l unloading curve can be
explained on the assumption of the simultaneous operation of the following two factors: a magnetoelastic
effect, which changes the magnetization of the ferromagnetic component as a result of unloading, and a
possible change in the total ferromagnetic-phase content in the deformed sample. An increase in the load
applied to an elastically or plastically deformed ferromagnet to the yield strength is known to change its
magnetization (so-called Villari effect) [9, 16]. In our
case, mechanical stresses change the magnetic properties of the α' martensite. It should be noted that the α'
martensite also accumulates in the sample during tension, which should increase the magnetic signal.
Unloading first leads to a significant and almost instantaneous increase in the magnetometer signal ∆I+, which
indicates a negative sign of the Villari effect for the α'
martensite. As is seen from Fig. 3, the magnitude of this
RUSSIAN METALLURGY (METALLY) Vol. 2008 No. 5
MAGNETOMETRIC STUDY OF THE γ
In some cases, we detected a significant decrease in
the magnetization of plastically deformed steel samples
∆I– in the second part of the unloading cycle. As is seen
from Fig. 3, this effect in irradiated 12Kh18N10T steel
samples begins to manifest itself at lower strains compared to the unirradiated samples (the residual strains δ
for the unirradiated and irradiated steels are ~40 and
27.5%, respectively, and the initial external stresses σ at
the initial stage of unloading were close to each other
(727 and 713 MPa, respectively)). We could assume that
the decrease in the magnetization is caused by the
redistribution of internal stresses in the deformed sample upon unloading, which results in a local stress jump
in some areas. Quantitatively, this effect is likely to be
smaller than the initial increase ∆I+. The ∆I curves of the
steel samples in an unloading cycle at σ _ σu satis-fies
this explanation. However, when a sample with the state
σ ≥ σu is unloaded, the decrease in the magnetiza-tion
becomes comparable with and, then, exceeds its initial
increase during the unloading of the sample due to the
Villari effect. This finding indicates that, when a steel
sample is deformed in the state near or beyond the
ultimate tensile strength, an additional factor, which
strongly affects the magnetic signal at the stage of
unloading, manifests itself. In particular, this factor can
be represented by a decrease in the α'-martensite content when elastic stresses are relieved.
If this hypothesis is taken as a working hypothesis,
then, according to the generally accepted classification
of martensite in steels, part of the α' martensite whose
content can change during unloading can be called
“elastic martensite” or “high-temperature stress martensite.”
The formation of the elastic martensite during the action
of elastic stresses in a plastically deformed steel polycrystal
can be explained using the general idea of local overstresses
in certain places in a loaded sample. For example, the
authors of [17] showed that the stress distribution over the
cross section of a single-crystal sample is nonuniform
during uniaxial tension even in a single crystal. Stresses can
concentrate at dislocation pileups, radiation defects, aging
products, the intersec-tion of stacking faults, and so on. The
stress distribution in a polycrystal is more complex because
of the effect of grain boundaries, the orientation of
crystallites with respect to an applied load, and other
factors. In a poly-crystalline sample, the probability of the
appearance of local overstresses in the volume increases
even before the application of an external load. Thus, in
principle, the presence of local stresses that are equal to or
exceed the critical threshold of the α'-martensite formation
makes the γ
α' martensite transformation possible in a
certain microvolume when the applied load does not
exceed the yield strength of the material. This is valid
for the cases of both an elastically loaded sample
(stress martensite) and a plastically deformed sample
that is first unloaded and then again loaded. The
higher the content of regions with local overstresses in
a poly-crystal, the higher the concentration of α 'martensite
RUSSIAN METALLURGY (METALLY) Vol. 2008 No. 5
α' MARTENSITE TRANSFORMATION
395
I/I0
20
1'
15
2'
10
2
1
5
0
10
20
30
40
50 δ, %
Fig. 5. Change in the magnetization of (1, 2) unirradiated
and (1', 2') irradiated 12Kh18N10T steel samples during
tensile deformation: (1, 1') dynamic curves obtained in a
loading cycle and (2, 2') static curves obtained in an
unload-ing cycle. I is the magnetization related to a change
in the α'-martensite content in a sample, Mf(∆l) = I(∆l)/I0,
where I0 is the “zero” of the magnetic transducer.
nucleation centers. The critical factors that affect the
stability of α'-martensite microcrystals are the temperature in a microvolume and the level of local microstresses. In principle, a decrease in the total projection of
internal stresses onto the preferred growth direction of
martensite nucleation centers at a constant temperature
or an increase in the temperature in a microvolume can
cause not only the termination of growth but also an
instability of the bcc lattice. We assume that the reverse
α'
γ transformation is facilitated in small α'-martensite inclusions having no clear crystallographic
interface with the austenitic matrix. This state of the
α' martensite is most likely to correspond to the
elastic martensite.
Neutron-irradiated austenite has numerous
radiation defects, which can serve as natural obstacles
to disloca-tion slip and can eventually lead to the
formation of many nucleation centers of α'-martensite
microcrys-tals. This explains the fact of the earlier
(concerning strain) decrease in the magnetization of
the sample and the increase in ∆I during unloading of
the neutron-irra-diated 12Kh18N10T steel as
compared to the unirradi-ated steel.
We plotted the static curves, or the remanent magnetization Is curves, for the irradiated and initial steel
samples using a set of points corresponding to the magnetizations of the samples after complete unloading at
various stages of tension up to failure (Fig. 5). The
arrows in Fig. 5 connect the points of the beginning and
the end of unloading. It is seen that the magnetization ID
and remanent magnetization Is curves plotted under the
loading of the neutron-irradiated (5  1018 cm–2) steel are
well above the corresponding curves of the unirradiated
steel. The topologies of the curves for the irradiated and
unirradiated steels are the same: the magnetizations of
the deformed samples under loading
396
MAKSIMKIN, TSAI
(Is – ID)/ID
4
tion in the steel deformed at 20C: (i) a decrease in the
kinetic values of the relative strain and stresses for the
appearance of the α' martensite in the irradiated steel to
4% and 470 MPa, respectively, as compared to 17%
and 540 MPa for the unirradiated material; (ii) insignificant radiation hardening and a high retained plasticity
after irradiation and, hence, a high deformationinduced martensite content in both the neck and body
of the sample as compared to the unirradiated steel. A
high plasticity is retained in irradiated austenitic steels
over a rather narrow irradiation dose range [14] and is
1
3
2
1
likely to result from a resonance effect in the kinetics of
2
0
10
20
30
40
50 δ, %
Fig. 6. Contribution of dynamic factors ID to the magnetization of the 12Kh18N10T steel during the tension of (1) unir-
radiated and (2) neutron-irradiated samples.
change with δ (residual strain) according to a nearexponential law. However, remanent magnetization
curves 2 and 2' contain “steps,” which are likely to be
caused by the end of the uniform deformation of the
gage portion of the sample and by the concentration of
the α'-martensite formation at the sites of a localized
flow.
Figure 6 shows the dependences of the dynamic
contributions (Is – ID)/ID to magnetization ID on the
sample strain δ under loading that are plotted using the
data shown in Fig. 5. The curves of the irradiated and
unirradiated steels are strongly different. The contribution of the dynamic factors to the magnetization for the
initial steel can exceed ID by several times (this is
clearly visible at low strains), and the contribution
becomes lower than ID when the ultimate tensile
strength is approached. In other words, the magnetometric data for the initial 12Kh18N10T steel give an
underestimated α'-martensite content during deformation to the ultimate tensile strength because of the
action of the magnetoelastic effect. The manifestation
of the dynamic factors in the irradiated steel is much
weaker. As a rule, their contribution does not exceed
(1/2)ID and weakly depends on the degree of plastic
deformation.
Thus, we simultaneously recorded the load, elongation, and magnetization of the cylindrical samples of
the unirradiated and neutron-irradiated (to a dose of
5  1018 cm–2) 12Kh18N10T steel during uniaxial tension and obtained the dynamic and static kinetic dependences of the ferromagnetic α'-martensite content for
periodic unloading and
repeated loading. Using the
change in the magnetization of the deformed steel, we
estimated the change in the relative α'-martensite content in the sample.
With magnetometric measurements, we revealed the
following specific features of the γ
α' transforma-
α'-martensite formation because of the complex effect
of the postirradiation state of the microstructure and the
deformation conditions.
We found that the magnetic signal (i.e., the related
α'-martensite content) depends on the state (loaded or
unloaded) of the deformed steel sample. When the sample is unloaded (or repeatedly loaded), its magnetization curve has a complex shape close to a parabola with
branches directed down. The magnetization curve of
the unloaded steel sample can be explained by the
action of the following two dynamic factors: first, a
magnetoelastic effect, which increases the magnetization during unloading and, second, a possible decrease
in the total α'-martensite content after unloading. The
second factor, which is responsible for a decrease in the
magnetization, becomes noticeable only at a stress of
~710 MPa (in the irradiated and unirradiated steels), at
which the residual strain is 27.5% in the irradiated steel
and 40% in the unirradiated steel. The part of the α'
martensite that disappears when the elastic stresses in
the sample are relieved and appears upon repeated
loading is characterized as high-temperature stress
martensite, or elastic martensite. Therefore, the authors
of [18] concluded that the partially reversible change in
the α'-martensite content induced by a change in the
load can lead to a decrease in the fatigue life of the
12Kh18N10T steel due to the intense accumulation of
latent energy.
CONCLUSIONS
(1) The dynamic factors caused by elastic structural
interactions were shown to affect the results of the magnetometric measurements performed during the plastic
deformation of steel samples.
(2) If the dynamic characteristics obtained during
deformation are not taken into account for the unirradiated steel, the α'-martensite content in it can be substantially underestimated.
(3) Neutron irradiation was shown to strongly
weaken the quantitative manifestation of the elastic
effects in the steel (as a result, the dynamic contribution
to the magnetization is ≤(1/2)ID), and the estimation of
the change in the α'-martensite content during deformation using the magnetometric data obtained during
loading is more accurate.
RUSSIAN METALLURGY (METALLY) Vol. 2008 No. 5
MAGNETOMETRIC STUDY OF THE γ
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