Soham Impex SI-TIG-300, Руководство по эксплуатации

Страница: 45 / 47

[42]

SMAW (Stick) welding technique
One of the most common types of arc welding is manual metal arc welding (MMA) or stick welding. An
electric current is used to strike an arc between the base material and a consumable electrode rod or
‗stick‘.
The electrode rod is made of a material that is compatible with the base material being welded
and is covered with a flux that gives off gaseous vapours that serve as a shielding gas and providing a
layer of slag, both of which protect the weld area from atmospheric contamination. The electrode core
itself acts as filler material the residue from the flux that forms a slag covering over the weld metal must
be chipped away after welding.
STICK ARC
ARC Ignition Weld pool Protection Slag
•
The arc is initiated by momentarily touching the electrode to the base metal.
•
The heat of the arc melts the surface of the base metal to form a molten pool at the end
of the electrode.
•
The melted electrode metal is transferred across the arc into the molten pool and
becomes the deposited weld metal.
•
The deposit is covered and protected by a slag which comes from the electrode
coating.
•
The arc and the immediate area are enveloped by an atmosphere of protective gas.
Manual metal arc (stick) electrodes have a solid metal wire core and a flux coating.
These electrodes are identified by the wire diameter and by a series of letters and
numbers. The letters and numbers identify the metal alloy and the intended use of the
electrode.
The Metal Wire Core works as conductor of the current that maintains the arc.