General Safety; Manual Arc Welding; Duty Cycle - STAMOS S-MTM 220 Manuel D'utilisation

U S E R M A N U A L

GENERAL SAFETY

If you have doubts on connecting and operating with this device, please contact the
manufacturer. The user must read this manual carefully before first use of the device.
MIG/MAG
The welding equipment for manual arc welding with automatic wire feed allows the
joining of metal parts through a melting process of the edges to be joined and the
filler metal. Melting is caused by the arc, which is formed between the material to be
welded and the metal wire continuously emerging from the end of the burner. Metal
wire serves as a filler material for the connection of the parts. Higher welding cur¬rent
allows welding of bigger plates. For damages resulting from failure to comply with these
instructions, no liability is accepted.
TUNGSTEN INERT GAS WELDING (DEU. WIG; ENG. TIG)
The tungsten inert gas welding technology (TIG welding) comes from the U.S., where
it became known in 1936 as argon welding. Only after the second World War II was it
introduced in Germany. In English-speaking countries this method is called TIG, after the
English word for tungsten. The method offers several interesting advantages over other
fusion welding processes. For example, it is universally applicable: if a metallic material is
at all suitable for welding, then it can be processed with this procedure. Additionally it is
also a very „clean" process, which produces very little pollution and little splashes and,
when used correctly, guarantees a high quality welded joint. A particular advantage of
TIG welding is also the fact that compared to other methods employing a consumable
electrode, the addition of a filler material and the current are not linked.
Therefore the welder has control over the power:
• it may be optimally matched to the welding task and it is only necessary to add as
much filler as is currently required. This makes the process particularly suitable for
welding root passes and for welding in forced positions.
• due to the relatively low and small-scale heat input there is little tendency for the
workpieces to warp during welding.
• these advantages have caused the process to be particularly suitable for welding of
air planes and space vehicles, construction elements used in nuclear installations
and installation components and equipment for chemical plants.
MMA

MANUAL ARC WELDING

Manual arc welding, briefly called MMA (Manual Metal Arc Welding), is one of the oldest
electric welding procedures used for metallic materials, which is still used today. In
1891 Nikolai Gavrilovich Slawjanow replaced the carbon electrodes commonly used in
his time for arc welding by a metal rod that was both the arc carrier and filler metal.
Since the first rod electrodes were not coated, the weld itself was not protected from
oxidation. Therefore these electrodes were difficult to weld. The electric arc burning
between an electrode and the workpiece is used as the heat source for welding.
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Rev. 15.05.2020
The high temperature of the arc melts the material in the welding area. The rod elec-
trode simultaneously melts off acting as a filler material to form the weld bead. Both
AC and DC currents can be used to power the process. Rod electrodes are used as
filler material in arc welding. For each welding type there are appropriate electrodes,
e.g. for build-up welding and joint welding. Information concerning the nature, charac-
teristics and application of an electrode is provided by the brief label, which is printed
on each electrode package. The gases produced by the melting of the electrode coa-
ting are used to stabilise the arc and separate the liquid metal transfer in the arc from
the influences of the surrounding air and to reduce the burning of alloy components.
Apart from that the melted coating also produces slag. This liquid is lighter than liquid
steel and is washed onto the weld. This enables a slow cooling process and thus lower
shrinkage stress. The anode (positive pole) is heated by electron bombardment and
positive metal ions flow from there to the workpiece. Therefore consumable elec-
trodes are mostly used as anodes with the workpiece material acting as a negative
pole. In TIG welding the electrode has a negative pole in order to keep the degree of
removal low. Arc welding is used in the construction industry (bridge supports) but
also in precision engineering. The following rule applies regardless of application: The
thinner the material, the more expensive the equipment. Due to low current levels
(necessary not to burn through materials under 1 mm wall thickness), a significantly
more complex control process is required.
GENERAL SAFETY
If you have doubts on connecting and operating with this device, please contact the
manufacturer. The user must read this manual carefully before first use of the device.

DUTY CYCLE

Duty cycle is a welding equipment specification which defines the number of minutes,
within a 10 minute period, during which a given welder can safely produce a particular
welding current. For example, a 200 amp welder with a 60% duty cycle must be „res-
ted" for at least 4 minutes after 6 minutes of continuous welding with 200 amp..
WORK AREA PRECAUTIONS
• Keep your work area clean and well lit. Cluttered benches and dark areas invite
accidents.
• Do not operate power tools in explosive atmospheres, such as in the presence
of flammable liquids, gases, or dust. Power tools create sparks which may ignite
the dust or fumes.
• Keep bystanders, children, and visitors away while operating a power tool.
Dis¬tractions can cause you to lose control. Protect others in the work area
from debris such as chips and sparks. Provide barriers or shields as needed.
Rev. 15.05.2020
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