Journal of Power and Energy Engineering, 2013, 1, 51-53
http://dx.doi.org/10.4236/jpee.2013.17009 Published Online December 2013 (http://www.scirp.org/journal/jpee)
51
Estimation of the Temp erature in th e We ld Penet ration
Channel in Electron Beam Welding
D. N. Trushnikov, E. S . S alomatova, V. Ya. Belenkiy
Perm National Research Polytechnic University, Perm, Russia.
Received September 2013
ABSTRACT
In this paper, the method of experimental estimation of the temperature in a penetration channel in electron beam weld-
ing is described on the basis of chemical elements concentration in the vapors above welding zone. The temperature of
a vapor-gas phase i n the penetra tion channel is determined when equating calculated and experimental concentrations of
the elements.
Keywords: Electron Beam Welding; The Chemical Composition of the Weld; Austenitny Stainless Steel;
Thermodynamic Calculations; Steam Pressure in the Channel
1. Introduction
Electron beam welding (EBW) plays a special role among
welding methods because of high power concentration in
a welding electron beam and the ability of its deep pene-
tration into the metal. These cause wide application of
EBW in the manufacture of parts for critical products
from various steels and alloys.
At the moment, there is a considerable success in the
numerical simulation of electron beam and laser welding
by static electron beam [2-4], but the complete dynamic
models describing the processes in penetration channel at
EBW with periodical influence on the electron beam are
absent till present. The complicity and speed of these
processes make it difficult to carry out computer simula-
tion and numerical experiments even at the modern level,
there is the necessity to search the ways for experimental
investigations. Besides, when simulating laser welding,
which is similar to the electron beam processes, the tem-
perature in the penetration channel is usually taken to be
equal to the boiling temperature at the atmospheric pres-
sure, but electron beam welding is carried out under va-
cuum, and this approach for the simulation of electron
beam welding is not suitable for getting the required ac-
curacy of the results.
Experimental methods for measuring the temperature
in the penetration channel also face with difficulties. The
applying of pyrometrical methods is complicated by the
significant value of secondary light emission from a weld-
ing zone.
2. Research Methods
In this paper the method of experimental estimation of
the temperature in a penetration channel in electron beam
welding is described on the basis of chemical elements
concentration in the vapors above welding zone.
The background of the experimental technique was the
determination of the temperature in a penetration channel
in electron beam welding on the basis of chemical com-
position of the vapors formed above welding zone. For
the experimental estimation of the vapor composition
with the use of electron beam apparatus with the energy
aggregate ELA-6VCh, produced by “SELMI” (Ukrane),
oscillating electron beam passed along the sample made
of austenitic steel 321. The plate made from aluminium
alloy 512,0 (AMц-3) has been settled around the zone of
electron beam influence on the sample (at a distance of
15 mm). The material of the plate was chosen in terms of
minimal coincidence of the alloy chemical composition
with chemical composition of the steel 321. Electron
beam power in the experiments was 3.6 kW (accelerating
voltage was 60 kV), welding speed was 3.2 mm/s, oscil-
lation frequency and amplitude of the beam we re 650 Hz
and 1 mm, respectively.
The experiment pattern is shown in Figure 1. During
the influence of oscillating electron beam on the sample,
which was made from the steel 321, in dagger penetra-
tion mode, evaporation of the elements occurred with
their following d eposition on the plate made from alum i-
nium alloy.
Later roentgen fluorescent analysis of the obtained

Estimation of the Temperature in the Weld Penetration Channel in Electron Beam Welding
52
Figure 1. The experiment pattern on the analysis of the
elements evaporation from steel 321 during electron beam
action: 1—electron gun; 2—electron beam; 3—melt metal;
4—base material; 5—aluminium plate; 6—metal vapors
from the zone of electron beam action.
coating, aluminium plate and the sample, which was in-
fluenced by electron beam, has been taken. Data obtained
are represented in Tables 1-3.
The elements from the plate were subtracted from the
chemical composition of the coating to determine the
amount of alloying elements evaporated from the steel
321 during oscillating electron beam action. Results of
the calculation are represented in Table 4.
Thus during electron beam influence on the sample,
made from steel 321, an intensive evaporation of iron,
chrome and manganese takes place.
Obtained experimental data were compared with the
results of thermodynamic calculations to estimate the tem-
perature in the penetration channel, which was formed in
the metal by electron beam.
At thermodynamic calculations the content of each
chemical element Сi in vapor-gas phase of penetration
channel was determined on the basis of the chemical
composition of metal sample (Table 2) according to the
equation:
i
itotal
P
CP
=
(1)
where total vapor pressure Ptotal in the channel is the sum
of partial pressures of the elements from the alloy (Рi).
It can be seen that vapor pressure in the channel main-
ly depends on the pressures of three elements which are
iron, chrome and manganese.
Then the results of thermodynamic calculation, made
with the use of the Equation (1), were compared with the
results of chemical analysis of the deposited coating to
estimate the temperature of a vapor-gas phase in penetra-
tion channel. Calculation results for the chemical comp o-
sition of vapor-gas phase within the electron beam weld-
ing zone are represented in Figure 2 (only for iron,
chrome and manganese, because the content of the other
elements can be neglected), and the concentrations of
chemical elements obtained with the use of roentgen flu-
Table 1. Chemical composition of aluminium plate (alloy
512,0 (AМц-3)).
Chemical elements Al Mn Fe S Crо Zn Ti Ni
Element content, % 98.88 0.40 0.28 0.18 0.12 0.04 0.04 0.03
Table 2. Chemical composition of the sample (steel 321).
Chemical elements Mn Si Cr Ti Ni C Fe
Element content, % 1.27 0.50 18.99 0.59 10.14 0.09 68.42
Table 3. Chemical composition of the coating.
Chemical elements Fe Cr Mn Al Ni
Element content, % 33.36 24.94 34.81 2.85 1.891
Table 4. Amount of alloying elements evaporated from steel
321.
Chemical elements Fe Cr Mn Ni
Element content, % 33.08 24.82 34.41 1.891
Figure 2. Correlation between iron, manganese and chrome
concentrations in the channel for the steel 321 and the tem-
perature.
orescent analysis at experimental research (horizontal
lines) are also shown in the figure.
The temperature of a vapor-gas phase in the penetra-
tion channel is determined when equating calculated and
experimental concentrations of the elements, and it was
2590 K (for Fe), 2610 K (for Cr) and 2730 K (for Mn).
As it is clear from the data obtained the difference be-
tween the temperatures is insignificant (about 5 %) and it
can be caused by indirect character of the applied method
which accuracy is still difficult to estimate.
Thus the temperature determined in the experiment on
the basis of the analysis of components evaporation from
steel 321 was 2600 K. It is necessary to note that the
temperature in the penetration channel is changeable in
depth and undergoes fluctuations over time. When elec-
tron beam oscillating the zone of maximal energy release
reciprocates from the surface to the depth of the channel
and reverses [5], the temperature of any single element of
the penetration channel becomes a periodic function. The
time -average temperature rises with the depth increasing
1
2
3
4
5
6
Temperature, К
Concentration of chemical elemen ts in the vapor-
gas channel , %
С
Fe
exper.
С
Mn
exper.
С
Fe
calc.
C
Cr
calc.
С
Cr
exper.
C
Mn
calc.

Estimation of the Temperature in the Weld Penetration Channel in Electron Beam Welding
53
in the penetration channel. At the same time significant
part of the vapors condenses on the walls during the
movement from the depth of the penetration channel [6].
The statement concerned is confirmed with the analysis
of the chemical composition of the weld seam along its
depth, which shows that noticeable depletion of the metal
with alloying elements takes p lace only in higher ar eas of
metal. According to this, the described method allows to
determine only a certain temperature of a higher part of
penetration channel which corresponds to a time-average
vapor composition. Obtained data are in a satisfactory
agreement with the results of the work [4].
The research was carryed out under the support of the
grants RFBR-Ural No. 11-08-96016, RFBR No. 13-08-
00397A and the financial support of the Ministry of edu-
cation of t he Perm region.
3. Conclusions
The method of experimental estimation of the tempera-
ture in the range of interaction of the beam and walls of
penetration channel has been suggested. The method is
based on vapor concentration measurement above weld-
ing zone with the use of chemical analysis of a film de-
posited on a substrate located near welding zone. The
temperature of higher areas of the penetration channel,
corresponding the time-average vapor composition at the
welding with depth of 7 mm of the steel 321, was about
2600 K. Experimentally determined temperature in the
channel was in a good agreement with existing estima-
tion.
The obtained results can be used further in the calcula-
tion of intensity of evaporation processes in the channel
it electron beam welding; this will permit to determine
the corresponding costs of thermal energy and to take
into account this factor at a numerical solution of the
connected thermal and hydrodynamic problem.
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