Smaw Electrode Polarity; Effects Of Stick Welding Various Materials - Thermal Arc ARC MASTER 175 TE Operating Manual

arc master 175 te

4.04 SMAW Electrode Polarity

Stick electrodes are generally connected to the "+"
Positive Output Terminal and the work lead to the
"−" Negative Output Terminal but if in doubt consult
the electrode manufacturer's literature for further
information.
4.05 Effects of Stick Welding Various
Materials
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.
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.
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
Metal Being Joined
Mild Steel
Mild Steel
Cast Iron
Stainless Steel
Copper, Bronze, Brass, Etc.
High Alloy Steel, Dissimilar
Metals, Crack Resistance, All
Hard-To Weld jobs
Operation
during welding by quenching after each weld or skip
welding to distribute the heat.
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.
Copper and Alloys
The most important factor is the high rate of heat
conductivity of copper, making pre-heating of heavy
sections necessary to give proper fusion of weld and
base metal.
Types of Electrodes
Arc Welding electrodes are classified into a number
of groups depending on their applications. There are
a great number of electrodes used for specialized
industrial purposes which are not of particular interest
for everyday general work. These include some low
hydrogen types for high tensile steel, cellulose types
for welding large diameter pipes, etc. The range of
electrodes dealt with in this publication will cover the
Electrode
E6013 Ideal electrodes for all general purpose work,
features include outstanding operator ap-
peal, easy arc starting, and low spatter.
E7014 All positional electrode for use on mild and
galvanized steel furniture, plates, fences,
gates, pipes and tanks, etc. Especially suit-
able for vertical-down welding.
99% Nickel Suitable for joining all cast irons except white
cast iron.
High corrosion resistance. Ideal for dairy
E318L-16
work etc.
Bronze 5.7 Easy to use electrode for marine fittings,
ERCUSI-A
water taps and valves, water through floats
arms, etc. Also for joining copper to steel
and for bronze overlays on steel shafts.
E312-16
It will weld most problematic job such as springs,
shafts, broken joins, mild steel to stainless and
alloy steels. Not suitable for aluminium.
4-4
oPeration
Comments
Manual 0-5116