ARC WELDING IN ARGON IN CZECHOSLOVAKIA

• Document Type: CREST
• Collection: General CIA Records
• Document Number (FOIA) /ESDN (CREST): CIA-RDP80-00809A000700060183-1
• Release Decision: RIPPUB
• Original Classification: R
• Document Page Count: 3
• Document Creation Date: December 22, 2016
• Document Release Date: September 30, 2011
• Sequence Number: 183
• Publication Date: May 3, 1952
• Content Type: REPORT

Sanitized Copy Approved for Release 2011/10/06: CIA-RDP80-00809A000700060183-1
CLASSIFICATION RESTRICTED
CENTRAL INTEGENCE AEG ryCy
INFORMATION FROM
FOREIGN DOCUMENTS OR RADIO BROADCASTS
COUNTRY Czechoslovakia
SUBJECT bcientific - Engineering, argon arc welding
HOW
PUBLISHED Monthly periodical
WHERE
PUBLISHED Prague
DATE
PUBLISHED 22 Dec 1951
LANGUAGE
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REPORT
Co NO.
DATE OF
INFORMATION 1951
DATE DIST. 3 May 1952
SUPPLEMENT TO
REPORT NO.
TI IS UNEVALUATED INFORMATION
ARC WELDING IN ARGON IN CZECEO$LOVARIA
The need to increase labor B7 +odutivity in Czechoslovakia calls for the in-
troduction of new work methods in many fields, including welding. Where steel
can be welded by the Volodinov or Mikhailov methods and by use of a submerged
electrode, light nonferrous metals and stainless steels must be subjected to are
welding in argon.
Two practical methods of inert-gas-shielded welding are currently in use:
welding with a wolfram electrode, and semiautomatic welding with the electrode
in the form of the welding wire. Both of these methods can be mechanized com-
pletely, thus accelerating production. The on15 inert gas which could be con-
sidered for use in Czechoslovakia at present is argon. The Ostrava Nitrogen
Works is producing it pure enough fc-,, welding. Both of these methods are ex-
tremely suitable for application to light metals. such as aluminum and magne-
hheI and their alloys. The advantage of inert-gas-s hielded.we]ding.Js evident even
where alternating current is used, since no fluxes need be applied because of
he cleansing properties of the inert gas which neutralizes the Canger of cor-
rosion of unremoved flux particles. The quality of the welds, their protection
from oxidation by inert gas, and the.eccelmWlcu of operating speeds all of which
are facilitated by these methods, are the principal reasons for welding even
copper and its alloys in this manner. As compared to acetylene welding, the
inert-gas-shielded method using argon tends to cause less deformation, because
of the concentration of heat within a small space under the arc.
In welding in a stream of argon and using wolfram electrodes, or, to call
the method by its Western name, Eeliarc welding, a suitable material must be
chosen for the nozzle, which is mounted on the holder and guides the stream of
argon. In working with aluminum and its alloys. it is possible to use nozzles
manufactured from oxidized aluminum. For other materials, particularly copper
and stainless steel, and also where direct current is used and in angle weld-
ing, these nozzles are unsuitable. A special, highly flame-resistant porcelain
is used abroad.. Various porcelains, pure silicon, and the Pythagorean substance
have been tested in Czechoslovakia; all of these materials, however, melted in'
the high temperature in the vic+.nity of the are. In the meantime, corundum noz-
zles ar' carving well. In large wolfram electrode holders, water-cooled nozzles
UM 'IAVY !.
ARM MI IJC I V'a B
DISTRIBUTION
STAT
Sanitized Copy Approved for Release 2011/10/06: CIA-RDP80-00809A000700060183-1
 Sanitized Copy Approved for Release 2011/10/06: CIA-RDP80-00809A000700060183-1
are customarily used. The nozzles are usually insulated from their holders by
a layer of ceramic materiel such as steatite. Inasmuch as the nozzle 1s water
cooled, it is important to insulate aSl metal parts of the holder with rubber
and disconnect the current when handling the apparatus.
Czechoslovakia does not produce its own wolfram electrodes; most of them
are imported from Austria. Frequently, leftover pieces of electrodes, after
atomic hydrogen welding, are used. Where larger electrodes are essential, bun-
dles of them may be used. The most desirable number of electrodes to be used in
one bundle is seven. Electrodes of material other than wolfram are unsatisfac-
tory Sometimes thorium and cerium are added, to improve the ability of the
electrodes to emit electrons.
Where sheets of greater th'.cknesses are to be welded, the use of wolfram
electrodes under argon has proved unsatisfactory, and the sec. . method,
tne welding wire itself act as electrode, is considered to be superior. Good
results een achieved in weing ora ory testsbbut In orractice as well. ~Sheets frand om its
0.6 too 0-65 millimeters b
thick have been weldea by this method. During operation, alternating current is
used, the arc is stabilized by high frequency, and a condenser block for suppres-
satusion It is possible to hook the high-frequency stabilizing appa-
r circuit either in series or in parallel. When connected
in series, the full welling current passes through the high-frequency coil, which
at this point must be either large or well cooled. A simpler device is available
for hooking up in parallel.
The MEZ (rioravske Elektrotechnic:x Zavody, Moravian Electrical Plants) re-
search organization [n Hachodd has developed a prototype of such a high-
frequency ionizing apparatus, which has a frequency of 2 megacycles. This fre-
quency is outside the radio broadcast band, to minimize interference. The MZZ
has also solved the problem of protecting the welding transformer by introducing
a blocking condenser into the welding circuit.
In the case of transformers whose empty loads are a minimum of 100-120 Volts,
the high-frequency apparatus can be used only at the precise moment of ignition.
In the case of transformers whose empty loads are 60-70 volte, the high-frequency
apparatus must remain in operation constantly. By taking test readings, it was
found that, considering the type of condensers produced in Czechoslovakia, it is
necessary to choose a condenser block of a capacity of apprL,