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Maintenance Welding of Steel

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.

  • 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.
  • MAGNA 307 AC-DC.  Is an alloy steel electrode for all mild and miscellaneous steels.
  • 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.