©
COPYRIGHT 1998 THE ESAB GROUP, INC. LESSON
II Gas Ions
- Shielding gas atoms that,
in the presence of an electrical current, lose one or more
electrons and therefore, carry a positive electrical charge. The provide
a more electrically conductive path
for the arc between the electrode and the work
piece. High
Frequency - (as
applied to gas-tungsten arc welding) An
alternating current consisting of over 50,000 cycles per second at high
voltage, low amperage that is superimposed
on the welding circuit in GTAW power
sources. It ionizes a path for non-touch arc starting and stabilizes the
arc when welding with alternating current.
Inert Gases - Gases
that are chemically inactive. They do not readily combine with other
elements. Flux
- In arc welding, fluxes
are formulations that, when subjected to the arc, act as
a cleaning agent by dissolving oxides,
releasing trapped gases and slag and generally
cleaning the weld metal by floating the impurities to the surface
where they solidify in the slag covering.
The flux also serves to reduce spatter and
contributes to weld bead shape. The flux may be the coating on the
electrode, inside the electrode as
in flux cored types, or in a granular form as used
in submerged arc welding. Current
Density - The
amperes per square inch of cross-sectional area of an electrode. High
current density results in high electrode
melt-off rate and a concentrated, deep penetrating
arc. Slope or
Slope Control
- A necessary feature in
welding power sources used for short circuiting arc welding.
Slope Control reduces the short circuiting current each time the
electrode touches the weld puddle (See
Section 2.5.3). Inductance
- (as applies to short circuiting
arc welding) A
feature in welding power sources designed for short circuiting arc welding
to retard the rate of current rise
each time the electrode touches the weld puddle.
