GALAGAR Smart 160 PFC Manual Técnico De Instrucciones página 33

5) Electrode manipulation
The electrode manipulation actually is a resultant movement in which the electrode
simultaneously moves in three basic directions: the electrode gradually moves along the welding
direction; the electrode gradually moves toward the weld crater; and the electrode transversely
swings. (See Fig.11-4) Electrode should be correctly manipulated in three movement directions
after arc is ignited. In butt welding and flat welding, the most important is to control the following
three aspects: welding angle, arc length and welding speed.
Welding angle: the electrode should be inclined in 70～80º forwards. (See Fig.11-5)
Arc length: the proper arc length is equal to the diameter of electrode in general.
Welding speed: proper welding speed should make the crater width of the weld bead about twice
the diameter of the electrode, and the surface of the weld bead should be flat with fine ripples. If
the welding speed is too high, and the weld bead is narrow and high, the ripples are rough, and
the fusion is not well implemented. If the welding speed is too low, the crater width is excessive,
and the workpiece is easy to be burned through. Besides, current should be proper, electrode
should be aligned, arc should be low, and welding speed should not be too high and should be
kept uniform during the whole welding process.
downwards feed
1-
move toward welding
2-
direction 3-transversely
swing
Fig.11-4 Three basic movement directions of electrode
flat welding
6) Arc extinguishing
Arc extinguishing is unavoidable during welding. Poor arc extinguishing may bring shallow weld
crater and poor density and strength of weld metal by which cracks, air holes, slag inclusion and
shortage the like are easy to be produced. Gradually pull the end of the electrode to the groove
and raise the arc when extinguishing arc, in order to narrow the weld crater and reduce the metal
and heat. Thus, defects such as cracks and air holes can be avoided. Pile up the weld metal of
the crater to make the weld crater sufficiently transferred. Then, remove the excessive part after
welding. The operation modes of arc extinguishing are shown in the figure below.
SMART 160 PFC
Fig.11-5 Angles of electrode in
Pag. 33