Tweco 175 SE Arc Master - Manuel (Page 28)

ARC MASTER 175 SE OpERATION
OPERATION 4-2 Manual 0-5054
Metal Being Joined Electrode Comments
Mild Steel E6013 Ideal electrodes for all general purpose work,
features include outstanding operator appeal,
easy arc starting, and low spatter.
Mild Steel E7014 All positional electrode for use on mild and
galvanized steel furniture, plates, fences, gates,
pipes and tanks, etc. Especially suitable for
vertical-down welding.
Cast Iron 99% Nickel Suitable for joining all cast irons except white
cast iron.
Stainless Steel E318L-16 High corrosion resistance. Ideal for dairy work
etc.
Copper, Bronze, Brass, Etc. Bronze
5.7 ERCUSI-A
Easy to use electrode for marine fittings, water
taps and valves, water through floats arms, etc.
Also for joining copper to steel and for bronze
overlays on steel shafts.
High Alloy Steel, Dissimilar
Metals, Crack Resistance, All
Hard-To Weld jobs
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.
4.02 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.
4.03 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 de-
posits 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
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 weld-
able. 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
vast majority of applications likely to be encountered
and are all easy to use.