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In maintenance welding
there is more steel welded than any other metal. Surveys show that there are more breakdowns caused
by steel weld failures than welds in any other
metal.
Many people believe
that steel is easy to weld and so they do not give
it much attention. Often in industry one hears
"Oh, it's
only mild steel", and so
they weld it with any cheap mild-steel welding rod
that is around. This attitude has cost industry more
lost production, more downtime, and more injuries
and damaged equipment than most people are aware of.
No doubt, simple mild steel
structures in a production factory are relatively
simple to weld since all or nearly all the variables
can be controlled. In maintenance, however, few of
the variables can be controlled. Laboratory
conditions simply do not exist in maintenance
welding. There are almost no simple easy maintenance
welds to make on mild steel or any other steel.
There are over 30 different common
types of mild steel and semi-mild steel electrodes
now in common usage. They were all designed for
production welding. The welder welds the one
application repeatedly so that he becomes highly
efficient on the highly repetitive applications he
makes. The ordinary production welding rods are
satisfactory where the variables are controlled.
The same electrodes are also sold
by many welding supply marketing companies for
maintenance welding applications for which they were
not designed. In maintenance welding, the conditions
are entirely different. The welder does not know the
analysis of the steel he is welding. He cannot
control the variables, such as joint design and in
maintenance the steel is often oily, rusty, painted
or dirty.
Production welding steel
electrodes have been designed for an exceedingly
limited range of applications - usually only one per
type.
In a production plant the variety
of steel welding is limited. For example, they may
weld only one type of structure - hot water tanks. These usually consist of only one type of joint such
as a butt joint. They probably use a positioner so
the welding is all performed flat (downhand). The
analysis of the clean new steel is known and they
probably have elaborate jigs and fixtures for
perfect alignment so distortion and warpage are not
problems either. They have selected an easy-to-weld
steel base metal to make the tanks from.
The maintenance welder, however,
is faced with a completely different set of
circumstances which require a welding electrode
designed for the different conditions he is
confronted with:
(1) The maintenance
mechanic more often than not, does not work full
time as a welder. In most industries welding is only
one of his important jobs. He attends to mechanical
repairs, electrical repairs, machine rebuilding,
plumbing, truck repair, etc. Since he doesn't
work exclusively as a welder, often he
understandably cannot develop maximum welding skill.
(2) The maintenance welder does
not do the same welding project repeatedly as the
production welder does. Every job is different. In
general the maintenance welder does not have a large
volume of one type of welding, but has an infinite
variety of applications. If he relies on production
welding rods he has to have possible as many as 30
different types of steel electrodes.
(3) The maintenance welder often
has to weld steel in confined areas of poor access
to the fracture awaiting repair.
(4) Maintenance
welding of steel is much more difficult than
production welding. In production, the engineers and
designers select an easy-to-weld steel. The
maintenance welder is often called upon to weld
"unweldable"
steels, eg, a pump shaft or
electric motor shaft. When the equipment was
manufactured there was no welding performed on the
shaft, thus the engineers or designers most likely
selected a free-machining steel which could be
machined at low cost.
Such a steel is considered
unweldable. Nevertheless, the maintenance welder has
to weld it. When he does he should always use
Magna Maintenance Welding Electrodes, as these
have been specially designed for the wide variety of
complex welding the maintenance department has to
do.
(5) The maintenance
welder often has to weld
"poor-fit"
applications, thick-to-thin, and
difficult metals such as alloy steel, galvanized
iron, high carbon steel, crack sensitive steel, and
steel of unknown analysis.
Steels that were
"simple
mild steel" when in a
production factory, and thus not difficult to weld,
become highly crack sensitive when later maintenance
welding has to be done on them. This is because they
are painted, have grease crayon marks, carbon
smudges from a cutting torch, or oil and grease on
them. All of these materials are carbonaceous. When
welding a piece of mild steel that has oil or other
carbonaceous material on it, the maintenance welder
is actually welding high carbon steel.
All of these carbonaceous
materials inherent on steel in maintenance
conditions, go into the weld as carbon and cause the
weld and weld area to become high carbon steels.
Every engineer knows that a high carbon steel weld
is highly crack sensitive.
(6) Maintenance
welding has to be of a higher quality standard than
production welding. In production welding, it is
customary for an inspector to follow the production
welder and locate any weld flaws
- usually about
3-6%.
In maintenance, the welder is
allowed zero defects. He usually has one broken part
to repair and he must weld it right the first time
or else a great deal of costly downtime or possibly
injury to his fellow workers will occur when the
weld fails in service.
(7) The maintenance
welder often has to weld equipment which is old and
the original design was not intended for today's
higher-speed, higher-powered requirements. Thus the
welds must be of greater toughness and greater
strength in maintenance than in production. Plus the
fact that the maintenance industry has to cope with
machinery that was poorly designed and needs to be
"beefed up"
and reinforced with higher
strength welds. The higher strength Magna
Maintenance Welding Electrodes are often the only
solution.
(8) In a production factory they
often weld a part and then stress-relieve or
heat-treat after welding. However, when this part
breaks down and has to be repair welded in the
field, it has to be repaired without dismantling and
it is impossible for stress relief after welding.
When Magna Maintenance Welding Electrodes are
used, problems such as these are simplified.
The maintenance welding solution
Magna has reduced the
complexity of steel welding in maintenance to where
it is no longer a cause of anxiety. In literally
hundreds of thousands of industries all over the
world they have discontinued using production
welding rods for steel maintenance and now use only
genuine Magna Maintenance Welding Electrodes
and Alloys.
Magna products are believed
to be the only welding electrodes and filler metals
in the world which are designed, produced, sold, and
serviced internationally, solely for maintenance.
All the other products are manufactured for
production.
Magna Electrodes and Alloy
Filler Metals are better for maintenance in several
important and completely exclusive ways:
(1) Magna products have
greater versatility built into them. Each product
gives optimum performance on a wide range of
different joint designs, different base-metal types
and different conditions.
(2) Magna products have
extra-high physical properties including higher
tensile strength, higher yield strength, higher
elongation and greater holding power. This gives the
welder an edge. The greater strength tends to
compensate for any flaws in the weld due to
inaccessibility, poor position, unknown composition,
and conditions that are not ideal, as well as
difficult-to-weld metals.
(3) Magna
Alloys and Electrodes are easier to apply. Even
unskilled welders can accomplish difficult jobs. Even more importantly, highly skilled welders can
achieve extraordinary results with a combination of
their skill and Magna's
ease of application.
Magna supplies five
electrodes for steel welding:
MAGNA 303 AC-DC. This one electrode
welds all steels and it is the only electrode a
small maintenance department needs to stock.
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MAGNA 305 AC-DC. This electrode
welds all low alloy steels and mild steels. It is
widely used for fabricating the new high strength
construction steels in the maintenance department.
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MAGNA 307 AC-DC. Is an alloy
steel electrode for all mild and miscellaneous
steels.
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MAGNA 393 AC-DC. An electrode
for stainless that provides improved corrosion
resistance and that runs off even small AC
"buzz-box"
welding machines
satisfactorily.
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