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. And 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.