.030
5
Figure
1- 2 illustrates one complete short arc cycle. As the wire touches
the weld pool (A), current begins to rise
to a short circuit current. When this high current is reached, the metal is transferred.
The arc is then reignited.
Because the wire is being fed faster than the arc can melt it, the arc will eventually
be extinguished
by another short (I). The cycle begins again. There is no metal transferred during
the arcing period;
only at the short circuits. To
insure good arc stability, relatively low welding currents must be employed when
using the short arc technique.
Table 1-1 illustrates the optimum current range for short circuiting metal transfer
with several wire sizes.
These ranges can be broadened, depending upon the shielding gas selected.
Table 1-1 – Optimum Short Arc Current
Range for Various Steel Wires WIRE
ELECTRODE DIAM. WELDING
CURRENT (AMPS) IN.
mm MINIMUM
MAXIMUM .76
50 150
.035 .89
75 175
.045 1.1
100 225
