S. SIVALINGAM, G. SURESHKANNAN: EFFECT OF PCGTAW ON ALLOY 690 WITH RESPECT TO MICROSEGREGATION ...
9–15
EFFECT OF PCGTAW ON THE INCONEL 690 ALLOY WITH
RESPECT TO MICROSEGREGATION ATTAINMENT IN
COMPARISON WITH THE BASE METAL PROCESSED WITH
AUTOGENOUS WELDING
VPLIV AVTOGENEGA VARJENJA S POSTOPKOM PCGTAW NA
ZLITINO INCONEL 690 GLEDE NA OBSEG MIKROSEGREGACIJ
V PRIMERJAVI S KONVENCIONALNIM AVTOGENIM
VARJENJEM S POSTOPKOM GTAW
Sengottaiyan Sivalingam
1*
, Gurusamy Sureshkannan
2
1
Department of Mechanical Engineering, KPR Institute of Engineering and Technology, Coimbatore, India
2
Department of Mechanical Engineering, Coimbatore Institute of Technology, Coimbatore, India
Prejem rokopisa – received: 2018-06-04; sprejem za objavo – accepted for publication: 2018-09-06
doi:10.17222/mit.2018.114
The mechanical properties and microstructure of weldments are always an imperative concern of researchers; therefore, the
change from continuous gas tungsten arc welding (GTAW) to pulsed-current gas tungsten arc welding (PCGTAW) was
investigated for alloy 690, using the autogenous welding method. The mechanical properties like the tensile strength and impact
were examined for both variants (continuous and pulsed-current gas tungsten arc welding). The microstructure was the
susceptible parameter, revealing a complete formation of the weldments. Hence, a complete analysis with an optical microscope
of up to 400 μm and a SEM of up to 7000 μm was performed during the described examination. This analysis showed that the
formation of the secondary phase was negligible in the case of the pulsed-current method, which was superior to the gas
tungsten arc welding, exhibiting a tensile strength of 641 MPa and an impact strength of 66 J.
Keywords: PCGTAW, GTAW, mechanical properties, SEM
Mehanskim lastnostim in mikrostrukturi zvarov raziskovalci vselej posve~ajo {e posebno pozornost. Zato so avtorji ~lanka
raziskovali prehod s kontinuirnega oblo~nega varjenja z volframovo elektrodo v za{~itnem plinu (GTAW) na pulzirajo~e
tokovno oblo~no varjenje z volframovo elektrodo pod za{~itnim plinom (PCGTAW) zlitine Inconel 690 z uporabo autogene
(brez dodajnega materiala) varilne metode. Dolo~ili in primerjali so mehanske lastnosti (natezno trdnost in udarno `ilavost)
obeh razli~ic varjenja (kontinuirno in tokovno pulzno oblo~no varjenje z volframovo elektrodo pod za{~itnim plinom). Popolna
tvorba mikrostrukture zvarov je bil odlo~ujo~ parameter oz. kriterij. Izvedli so kompletno metalografsko analizo pod opti~nim
mikroskopom do 400 μm in z vrsti~nim elektronskim mikroskopom (SEM) do 7000 μm. Te analize so pokazale, da je pri{lo do
zanemarljive tvorbe sekundarnih faz v primeru metode s pulzirajo~im elektri~nim tokom. Ta metoda (PCGTAW) je bolj{a od
oblo~nega varjenja z volframovo elektrodo pod za{~itnim plinom (GTAW), ker sta bili dose`eni precej vi{ja natezna trdnost
(641 MPa) in udarna `ilavost zvara (66 J).
Klju~ne besede: postopek PCGTAW, postopek GTAW, mehanske lastnosti, SEM
1 INTRODUCTION
As we know, stainless steel is the first metal to
undergo corrosion.
1
Researchers have been involved into
developing novel materials, such as nickel-based alloys
which are less prone to sensitization and corrosion. This
better quality exhibited by these alloys allows them to be
used in different areas like the chemical industry and the
nuclear-power-plant industry, specifically for steam
generators.
2–5
A varying high-temperature atmosphere
always enhances the susceptibility to pitting corrosion,
stress-cracking corrosion (SCC), trans-granular stress-
corrosion cracking (TGSCC) and inter-granular stress-
cracking corrosion (IGSCC), like in the cases of steam
generators and most of the thermal-power-plant sectors.
To resolve this issue, the material used should exhibit a
much better strength and good weldability.
6–8
Most of the
complex structures used today are welded to have per-
manent joints. The material exhibiting both charac-
teristics (good strength and weldability) is nickel-based
alloy 600. This alloy was first used in nickel alloys
showing good strength in comparison with stainless steel
with regard to the corrosion resistance.
9,10
It is used in
new areas like steam-generator tubing and other high-
temperature corrosive environments. Alloy 600 is not
completely resistant to different types of corrosion,
depending on the environment, in which it is used,
11
the
structural property
12
and the atmosphere, to which it is
exposed.
13
One of the reasons for this is its lower
percentage of chromium, which is 15 % of its weight.
This shows its need for further improvement, which
can be carried out by increasing the chromium content.
Therefore, super alloy 690 with a higher chromium
Materiali in tehnologije / Materials and technology 53 (2019) 1, 9–15 9
UDK 620.1:669.055:621.791.5 ISSN 1580-2949
Original scientific article/Izvirni znanstveni ~lanek MTAEC9, 53(1)9(2019)
*Corresponding author e-mail:
sivalaiyaa@gmail.com

content (about 30 % of its weight) was introduced to
overcome the corrosion with a higher resistance towards
it, specifically in an oxidizing environment. So, super
alloy Inconel-690 is usually applied as the melting-pot
material.
14
When Inconel-690 is continually exposed to a
high-level radioactive material, a depletion of Cr from
the alloy takes place, causing inter-granular attacks and
other difficulties, which lead to the alloy’s degradation.
15
To overcome this problem, it is essential to make an
alternative material for the melting pot or use a chemi-
cal-diffusion-fence coating to prevent the degradation of
the melting-pot material.
16,17
Inconel 690 exhibits
outstanding mechanical properties and is used for steam
generators of nuclear power plants. Hot tubes, usually
made from Inconel series 600 and 690 or Incoloy 800,
are significant components of a nuclear reactor’s steam
generator.
18,19
Lee et al.
20
examined the deformation
characteristic of Inconel 690 under loading using a
variety of environmental conditions and high strain rates.
For example, steam-generator hot tubes can be subjected
to high stresses during an operation owing to the gravity
and liquid flow.
21,22
The wear due to the fretting of SG
tubes finally received attention and we should be able to
diminish the fretting wear and assure a long-term
integrity. The researchers realized many examinations of
the SG-tube fretting wear and life predictions with the
help of the data from macroscopic analyses of the wear
coefficient, wear volume and so on.
23–27
In addition, a
microscopic analysis of fretting wear involves cracks,
structures, oxidation processes and the characteristics of
the oxide debris between contact surfaces.
28–31
This super alloy has been studied and analyzed for
various mechanical and metallurgical properties. Some
of the outcomes show that it is slightly harder to weld
than the other metals; GTAW welds were made with
fillers I-52 and I-82 and it was observed that I-52 was
better with respect to the strength of alloy 690. The
detailed result of GTAW with fillers I-52 and I-82 was
discussed.
32
Reports on steam generators examined with
a boiling-water-reactor (BWR) analysis say that a fail-
ure
33–34
like cracking often exists in the heat-affected-
zone and fusion-zone weldments. This finding allows the
researchers to search for novel materials. So, the
effectiveness of alloy 690 was proved with GTAW. In
addition, there should be an improvement in terms of the
microsegregation of the alloys. This major issue is
addressed by using PCGTAW of Inconel 690. Thus, the
most suitable filler chosen by H. T. Lee et al. is I-52
while I-82 reveals the tensile strength of around 570
MPa; they also report a better weldability of the I-52
filler. The I-52 filler weldments exhibit columnar den-
drites whereas I-82 exhibits equiaxed dendrites. I-82 has
a higher tensile strength than I-52. In I-82, the formation
of voids and cross slips leads to a fracture, while I-52 is
better in this respect.
35
Filler-based weldments show
various characteristics while welding without a filler is
autogenous welding. The above results clearly justify the
change from GTAW to PCGTAW. Instead of using
fillers, an alternative welding method was used to im-
prove the characteristics to the level of the base metal
and thus, for the analysis, autogenous GTAW and
PCGTAW are compared. The autogenous method was
not carried out for Inconel 690, which brought a new
aspect to this research. The features of the weldments
obtained with mechanical and microstructural analyses
are revealed in the sections below. Section 1 includes the
introduction discussing the 690 alloys with respect to the
previous critical reviews in terms of weldability and
different suitable welding techniques. Section 2 empha-
sizes the experimental setting for the welding. Section 3
describes the results obtained and the crucial outcomes.
Section 4 reveals the conclusions and explains how to
undertake further studies.
2 EXPERIMENTAL PART
Inconel 690 was procured in the hot-rolled form with
a thickness of 4 mm and a spectroscopic test was carried
out on the plate to ensure that the chemical composition
was in line with the standard reference.
36
The compo-
sition given in weight % was Ni 61.86, Cr 28.38, and the
remaining amount covered C, Mn, P, S, Si, Cu and Fe.
The weldments of autogenous GTAW and PCGTAW are
shown in Figures 1a and 1b. The metal plate was sliced
into dimensions of (130 × 55 × 4) mm with the help of a
wire-cut EDM machine. Before the welding, the plate
was cleaned with a 200-grade emery sheet and acetone in
order to remove oil, grease and other contaminants. The
weldments were fabricated with an ultra-arc inverter TIG
315 BP machine using the GTAW and PCGTAW auto-
genous processes. Since the autogenous process was
used, the welding had to be done on both sides to obtain
the full depth of penetration with four passes as seen on
Figures 1c and 1d. Argon was used as the shielding gas
to prevent the molten metal from contamination and to
improve the arc stability with a flow rate of 15 L/min.
S. SIVALINGAM, G. SURESHKANNAN: EFFECT OF PCGTAW ON ALLOY 690 WITH RESPECT TO MICROSEGREGATION ...
10 Materiali in tehnologije / Materials and technology 53 (2019) 1, 9–15
Figure 1: Photographic images of weldments made with: a) auto-
genous GTAW, b) autogenous PCGTAW, macrostructure images of the
weld joints: c) autogenous GTAW, d) autogenous PCGTAW

The welding parameters employed in this study were a
GTAW current of 125 A, a voltage of 10 V and a heat
input of 1.968 KJ/mm. For PCGTAW, they included a
current of 10 A, a voltage of 125 V, a pulse frequency of
7 Hz, a pulse width of 34 mm and a heat input of 0.878
KJ/mm. The heat supplied during GTAW and PCGTAW
was calculated using formulae 1 and 2, and the corres-
ponding input values were obtained.
The formula used to calculate the heat input for
GTAW is given below:
H
IV
S
=
×
× in (kJ mm
–1
) (1)
The following formulae were used to calculate the
heat input for PCGTAW:
I
ItIt
tt
m
ppbb
p b
=
×+×
+
() ()
()
in (A)
H
IV
S
=
×
×
m
 in (kJ mm
–1
) (2)
where, I
m
is the mean current in A; I
p
is the pulse
current in A; I
b
is the background current in A; t
b
is the
background current duration in ms; t
p
is the pulse-
current duration in ms; S is the welding speed in
mm/min; V is the voltage in V;  is the arc efficiency for
GTAW and PCGTAW, taken as 70 %.
37
In order to carry out a metallographic characteri-
zation, the welded plates were sliced into different pieces
along their transverse direction. A weld coupon is a com-
bination of the base metal, heat-affected zone and fusion
zone. Silicon carbide (SiC) grit paper ranging from 200
to 2000 grade was used to polish the weldments
manually. Then the samples were polished with alumina
powder (0.5 μm) and water to obtain the mirror finish
with the help of a double-disc polishing machine. This
was followed by electrolytic etching (10 w/% oxalic
acid, 12 V for 52 s) performed on the weld samples to
reveal the final microstructures. Optical and scanning
electron microscopy were used to observe the micro-
structures of the etched samples. Energy dispersive
X-ray spectroscopy (EDS) was used to analyze and
quantify the alloying-element segregation in the weld-
ments. The sliced weld coupons were mechanically
characterized with tensile, impact and bend tests in
ambient conditions. As per the ASTM E8/E-8M-13a
standard, the weld coupons were cut into three samples
to perform the tensile test. The strength and ductility of
the weld joints were measured with a universal testing
machine (Instron 8801). Three test trials were made to
ensure the repeatability. The toughness of the weld
samples were measured with the Charpy V-notch impact
test, in three trials. This test was carried out as per the
ASTM E-23 standard. In order to understand a weld
joint’s ability to withstand the bending load, a root bend
test was performed as per the ASTM E190 standard.
3 RESULTS AND DISCUSSION
3.1 Macrostructure examination
Macroscopic images of the alloy-690 weldments
made with autogenous PCGTAW and GTAW are shown
in Figures 1c and 1d. The weldments also underwent an
NDT. The macroscopic examination as well as the NDT
reveal the absence of abnormalities like porosities,
cracks and defects. This test shows that the optimized
welding parameters were adopted, and fusion was found
to be good with the fluid flow, showing an enhancement
in the weldments in achieving a better quality. During
the macrostructure examination of GTAW and PCGTAW,
no defects like cracks or abnormalities were found, as
seen on the photographs in Figures 1a and 1b, respect-
ively. This shows that the optimized welding parameters
were adopted, and fusion was found to be good with the
fluid flow, all together enhancing the weldments, which
exhibited a better quality.
3.2 Microstructure examination
The microstructures of the weldments produced with
conventional and pulsed-current GTAW are shown in
Figure 3. Figures 3a and 3b show the microstructures of
S. SIVALINGAM, G. SURESHKANNAN: EFFECT OF PCGTAW ON ALLOY 690 WITH RESPECT TO MICROSEGREGATION ...
Materiali in tehnologije / Materials and technology 53 (2019) 1, 9–15 11
Figure 2: Schematic diagram showing the dimensions of a tensile
specimen
Figure 3: Optical-microscope pictures of the weld joints of auto-
genous GTAW: a) fusion zone, b) weld interface. Optical-microscope
pictures of the weld joints of autogenous PCGTAW: c) fusion zone, d)
weld interface

different zones of the conventional GTAW weldments,
namely, the fusion zone and the weld interface, respect-
ively. The fusion zone consists of the following parts: (i)
planar dendrites, (ii) cellular dendrites. Some of the
coarse grains are seen in the HAZ in Figure 3b. This
examination clearly shows that the planar dendrites are
noticed at the fusion boundary and in the center, the
cellular dendrites are seen.
Microstructures of the pulsed-current weldments are
shown in Figures 3c and 3d. The microstructure of the
fusion zone consists of (i) planar dendrites and (ii)
equiaxed dendrites as shown in Figure 3c. The weld
interface along with the fusion zone, HAZ and base
metal are shown in Figure 3d. This analysis showed that
planar dendrites are identified at the fusion boundary,
whereas equiaxed dendrites are noticed in the area close
to the weld.
This examination of the GTAW weldments clearly
depicts that planar dendrites are noticed at the fusion
boundary, while the area close to the weld reveals
cellular dendrites, as shown in Figures 3a and 3b. The
analysis of the PCGTAW weldments indicates that planar
dendrites are identified at the fusion boundary, whereas
the area close to the weld shows equiaxed dendrites, as
seen in Figures 3c and 3d.
3.3 Tensile testing
The tensile test of the GTAW- and PCGTAW-pro-
cessed metal was done on a universal testing machine
(UTM). The weld samples were tested several times to
get the mean values, which are listed in Table 1. From
these values, it is clear that the PCGTAW sample has
more strength than the GTAW sample. The photographs
of the tested samples are shown in Figures 4a and 4b.
SEM fractographs reveal the presence of microvoids,
causing a failure, which occurred in the ductile mode as
shown in Figures 4c and 4d.
The strength values of the welded samples are listed
in Table 1. This shows that the strength of PCGTAW
(641 MPa) is 20 % greater than that of GTAW (511
MPa); hence, PCGTAW is stronger when compared to
GTAW. The strength of PCGTAW is more or less equal
to the base metal. The elemental values shown in Table 2
indicate a severe segregation of Cr in the interdendritic
region of GTAW, which is higher than that of PCGTAW,
revealing that PCGTAW is superior with regard to the
joint strength.
Table 1: Results of the tensile tests of the welds produced using auto-
genous GTAW and PCGTAW
Welding process Trial no.
UTS
(MPa)
Average
UTS (MPa)
Alloy 690 637.9
Autogenous GTAW
1 488.4
511 2 506.6
3 539.6
Autogenous PCGTAW
1 639
641 2 641
3 643
3.4 Impact testing
The impact test of the GTAW and PCGTAW metal
was done using the Charpy method. This test was done
to measure the objects’ ability to resist a high rate of
loading. It was done for multiple trails and the average
amount of the energy absorbed by a specimen and the
toughness values were measured. This test indicates that
the pulsed-current weld sample had a higher ability to
absorb the energy than the GTAW sample. The photo-
graphs of the tested samples are shown in Figure 5.
SEM fractographs reveal the presence of microvoids,
causing a failure, which occurred in the ductile mode as
shown in Figure 5.
S. SIVALINGAM, G. SURESHKANNAN: EFFECT OF PCGTAW ON ALLOY 690 WITH RESPECT TO MICROSEGREGATION ...
12 Materiali in tehnologije / Materials and technology 53 (2019) 1, 9–15
Figure 5: Impact test of the fractured specimens: a) autogenous
GTAW, b) autogenous PCGTAW; photographs of SEM fractographs of
impact-fractured specimens: c) autogenous GTAW, d) autogenous
PCGTAW
Figure 4: Photographs of the tensile test of fractured specimens:
a) autogenous GTAW, b) autogenous PCGTAW. Photographs of SEM
fractographs of tensile fractured specimens: c) autogenous GTAW, d)
autogenous PCGTAW

The impact toughness value for the base metal is
71.3 J; autogenous GTAW shows the average value of
42.6 J and autogenous PCGTAW shows the average
value of 66 J. This indicates that the toughness of
PCGTAW is 54.92 % greater than that of GTAW, hence
exhibiting a better tendency to absorb energy. This was
proven with the SEM/EDS examinations of the secon-
dary phases obtained with PCGTAW.
3.5 SEM/EDS studies
Autogenous GTAW
SEM/EDS results acquired from different GTAW
zones (the weld center and weld interface) are shown in
Figures 6a and 6b. The values of the major alloying
elements such as Ni, Cr, Fe obtained with the EDS
analysis are shown in Table 2. A high-magnification
SEM micrograph of the fusion-zone weld center is
shown in Figure 6a. It is obvious that planar dendrites
are enriched all over the weld centre. It is also noticed
that secondary TCP (topologically closed packed) phases
are in the fusion-zone weld center. Figure 6a (i, ii)
shows the EDS analysis of the weld-center (WC) den-
drite core and interdendritic region, respectively. From
Figure 6a (i, ii), it is clear that the interdendritic region
is enriched with Cr. The dendrite core alloying-element
chemical composition matches the base-metal compo-
sition. Figure 6b shows a high-magnification SEM
image of the weld interface. It also contains planar
dendrites throughout the weldments. The weld-interface
EDS analysis of the dendrite core and interdendritic
region is shown in Figure 6b (iii, iv). An observation
similar to that of the weld center is noticed.
Autogenous PCGTAW
SEM/EDS results obtained from different PCGTAW
zones (the weld center, WC, and weld interface, WI) are
shown in Figures 6c and 6d. It is found that planar and
equiaxed dendrites are enriched all over the weld center.
Figure 6c (i, ii) shows the EDS analysis of the weld-
center dendrite core and interdendritic region indicating
that the chemical composition of the alloying elements
matches the composition of the base metal. Figure 6
shows a high-magnification image of the weld interface.
It also contains planar dendrites throughout the weld-
ments. The weld-interface EDS analysis of the dendrite
core and interdendritic region is shown in Figure 6d (iii,
iv). An observation similar to that of the weld center is
noticed.
The change from GTAW to PCGTAW is advant-
ageous due to the reasons discussed henceforth. The
outcomes of GTAW and PCGTAW are shown in Figures
6a and 6b) and (i–iv), and Figures 6c and 6d) and (i–iv),
respectively. The temperature-gradient parameter slowly
S. SIVALINGAM, G. SURESHKANNAN: EFFECT OF PCGTAW ON ALLOY 690 WITH RESPECT TO MICROSEGREGATION ...
Materiali in tehnologije / Materials and technology 53 (2019) 1, 9–15 13
Figure 6: SEM/EDS analysis for autogenous GTAW: a) SEM weld center, b) SEM weld interface, i) EDS of weld-center dendritic core, ii) EDS
of weld-center interdendritic region, iii) EDS of weld-interface dendritic core, and iv) EDS of weld-interface interdendritic region. SEM/EDS
analysis for autogenous PCGTAW: c) SEM weld center, d) SEM weld interface, i) EDS of weld-center dendritic core, ii) EDS of weld-center
interdendritic region, iii) EDS of weld-interface dendritic core, and iv) EDS of weld-interface interdendritic region

decreases from the cores of the weldments to the fusion
zones. This temperature distribution allows the formation
of equiaxed dendrites in the weldments, shown only in
the case of PCGTAW. The fluid flow is found to be
exceptional owing to the cyclic repetition of solidifi-
cation and melting due to the intermittent supply of heat.
Superior solidification provides for a better fusion zone
with a narrow HAZ. These supporting parameters are
attained in the PCGTAW weldments, having the values
of Ni-61.32, Cr-29.65 and Fe-9.03 while the base-metal
values are Ni-61.86, Cr-28.38 and Fe-10.40. The
SEM/EDS reports depicted the amount of microsegre-
gation in the dendritic and interdendritic regions of
GTAW and PCGTAW. The welding process caused
microsegregation affecting the mechanical and metallur-
gical properties of the weldments. The amounts of
microsegregation in different areas can be found using
the Scheil equation. This equation was used to study the
amount of microsegregation in the Ni-Cr-Fe alloys of
Inconel 690.
k
C
C
=
core
0
(3)
Here, C
core
– the elemental level in the dendrite core,
C
0
– the elemental level in the base metal
The value of k represents the elemental level in a
particular area. If the value of k is less than 1 (k<1)in
the dendrite core area, it indicates microsegregation; but
if the value of k is greater than 1 (k > 1), the segregation
is in the interdendritic core area. In the study, the
SEM/EDS analyses were carried out to find the
elemental level in the dendritic and interdendritic core
zones of the weldments, taking into account Ni, Cr and
Fe. Table 2 shows the values of k in the dendritic core
area of weld samples. This clearly shows that the micro-
segregation in the PCGTAW samples (k = 1.044) is lower
than in the GTAW weld samples (k = 0.93). It is ob-
served that the value of Cr is less than 1, which indicates
Cr segregation in the interdendritic zone of the GTAW
weldment, whereas in PCGTAW there is no microsegre-
gation. This study also indicates that the heat input is a
major factor for the microsegregation of alloying
elements; in addition, the solidification time increases
with an increase in the microsegregation of the alloying
elements in the interdendritic zone of weld samples. The
heat input during GTAW (1.96 KJ/mm) has a slow
cooling rate, whereas during PCGTAW (0.878 KJ/mm),
it has a high cooling rate. This increases the solidifi-
cation and diffusion of the alloying elements and allows
more time for cooling, which increases the segregation
of Cr in the interdendritic regions of the GTAW samples.
If the heat input is lower, the time required for the
formation of secondary phases is also lower. Therefore,
during PCGTAW the secondary phases are completely
reduced. The EDS analysis clearly shows that the
secondary phases’ interdendritic regions match the  phases. These  phases are the main source for hot
cracking in the fusion zones of weld samples. Finally, it
is noted that the formation of secondary phases in the
pulsed-current welding mode is completely reduced.
4 CONCLUSIONS
Nickel alloy 690 was welded with autogenous GTAW
and PCGTAW. Both methods were compared and the
following observations were made. The overall test
report shows that PCGTAW is better than GTAW due to
the following reasons,
• There are no defects in the weldments obtained with
GTAW and PCGTAW elucidating the superior quality
of a particular type of welding.
• In both cases, the fusion zone shows planar dendrites,
but they are smaller in the case of PCGTAW. Further,
the equiaxed dendrites are found only in the
PCGTAW samples, confirming a superior quality of
these welds, which exhibit better strength.
• The tensile test clearly shows that the strength of the
PCGTAW weldments is almost equal to the base
metal, being 641 MPa.
• The toughness value of 66 J confirms the superiority
of autogenous PCGTAW.
• The SEM/EDS examination clearly shows that the
microsegregation is lower in the case of PCGTAW.
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14 Materiali in tehnologije / Materials and technology 53 (2019) 1, 9–15
Table 2: Elemental levels in the dendritic core zone of the weld center
(k)
METHODS Ni Cr Fe
GTAW 1.01 0.93 1.51
PCGTAW 0.99 1.044 0.969

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