CIGWELD WELDSKILL 200HF, Operating Manual

Page: 42 / 60

OPERATING MANUAL
200HF
OPERATION 6-4 Manual 0-5406
6.07 Effects of Arc Welding Various
Materials
A. High tensile and alloy steels
The two most prominent effects of welding these
steels are the formation of a hardened zone in the
weld area, and, if suitable precautions are not taken,
the occurrence in this zone of under-bead cracks
may result. Hardened zone and under-bead cracks in
the weld area may be reduced by using the correct
electrodes, preheating, using higher current settings,
using larger electrodes sizes, short runs for larger
electrode deposits or tempering in a furnace.
B. Austenitic manganese steels
The effect on manganese steel of slow cooling from
high temperatures is to embrittle it. For this reason it
is absolutely essential to keep manganese steel cool
during welding by quenching after each weld or skip
welding to distribute the heat.
C. Cast Iron
Most types of cast iron, except white iron, are
weldable. White iron, because of its extreme
brittleness, generally cracks when attempts are made
to weld it. Trouble may also be experienced when
welding white-heart malleable, due to the porosity
caused by gas held in this type of iron.
D. Copper and alloys
The most important factor is the high rate of heat
conductivity of copper, making preheating of heavy
sections necessary to give proper fusion of weld and
base metal.
6.08 Arc Welding Practice
The techniques used for arc welding are almost
identical regardless of what types of metals are being
joined. Naturally enough, different types of electrodes
would be used for different metals as described in the
preceding section.
6.09 Welding Position
The electrodes dealt with in this publication can be
used in most positions, i.e. they are suitable for
welding in flat, horizontal, vertical and overhead
positions. Numerous applications call for welds to be
made in positions intermediate between these. Some
of the common types of welds are shown in Figures
6-2 through 6-9.
Art # A-07687
Figure 6-2: Flat position, down hand butt weld
Art # A-07688
Figure 6-3: Flat position, gravity fillet weld
Art # A-07689
Figure 6-4: Horizontal position, butt weld
Art # A-07690
Figure 6-5: Horizontal - Vertical (HV) position
Art A-07691
Figure 6-6: Vertical position, butt weld
Art # A-07692
Figure 6-7: Vertical position, fillet weld