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Welding of different grades of carbon steel.
 Sunday, February 8th 2015, 8:05 PM;  1341;  0;  +0 | 0 | -0
Any steel that happens to be an alloy of carbon and iron and contains a very little quantity of other metals can be referred to as carbon steel. There are four categories of carbon steel, namely high carbon steel, low carbon steel, medium carbon steel and mild carbon steel. The carbon steel welding procedures that are used by welders to weld pieces of carbon steel together depend on how much carbon they contain.
Procedures For Welding High Carbon Steel <a href="weld-delux.co.uk target="_blank"><img src="weld-delux.co.uk width="200" align="right" /></a>
Somewhere between .50% and 1.0% of carbon is present in high carbon steel. Dies, knives, springs and tools are made from high carbon steel. Usually, steel has to be preheated anywhere between 300 and 320 degree Celcius. For stress relief, the steel also undergoes postheat treatment and at times, annealing is also applied. Special furnaces are needed for postheating and cooling. Low hydrogen electrodes have to be used, and when the steel has to be welded for tools, special high carbon versions are used.
Procedures For Welding Low Carbon Steel
Low carbon steel is primarily also an alloy of carbon and iron but the percentage of carbon mixed in it tends to be low. For instance, of the total steel, there may be 0.15% carbon present in it. Typically, low carbon steel welding is performed for construction and fabrication. Welding low carbon steel tends to be the easiest. Arc, gas and resistance welding techniques are used by welders and they barely have to use any preheating or postheating. At times, they may use low hydrogen electrode welds, particularly when heavy sections and/or restrained joints have to be welded.
Procedures For Welding Medium Carbon Steel
The percentage of carbon in medium carbon steel tends to be somewhere between 0.30% and 0.50%. Welders usually have to weld medium carbon steel for gears, machine parts and steel that needs to be treated with heat. The fact of the matter is that any type of carbon steel welding can be used to weld this steel, but welders essentially need low hydrogen electrodes. Often, it becomes necessary to preheat the steel at temperatures between 150 and 260 degrees Celsius. For some sections, post-weld heating is also required so that the hardness that rapid cooling causes is reduced and stress on the metal is eliminated.
Procedures For Welding Mild Carbon Steel
The percentage of carbon in mild carbon steel is usually somewhere between 0.15% and 0.30%. Angle, bar stock and plate in industrial steel applications are made from mild carbon steel. Parts that require ductility and plasticity are also usually made from mild carbon steel. Generally, it is possible to weld this steel without interpass, preheat or postheating, unless the sections are very thick. Generally, thick sections have to be preheated at approximately 260 degrees Celsius.
Conclusion
Generally, carbon steel welding tends to be nearly seamless, and is performed using a MIG welder. There are barely any problems. The bottom line is that it is very easy to weld carbon steel and there are rarely any obstacles. Simply the right <a href="www.cranfield.ac.uk procedure has to be used depending on the percentage of carbon in them.
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