WELDING PROCESSES
WELDING PROCESSES AND THEIR ADVANTAGES AND LIMITATIONS
However, as part of our ‘golden’ celebrations, with the Association having been established 50 years ago, we decided to delve into the more unusual welding types and techniques used in various industries. Welding in its very basic form, is the
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joining of two metals through heat and/ or pressure. It’s an ancient process that dates back as far as the Iron Age. During that time, our ancestors hammered two metals together using heat. Much of the welding equipment and
techniques we see today can be traced back to the Industrial Revolution. Since then, the welding process has progressed significantly. Now, different types of welding processes are used depending on factors such as: Type of metal welded such as aluminium, copper, steel and so on. The thickness of the metal, and the welding environment (inside, outside, underwater, even in space). And, significantly, where the final product is going to function, in hospital, automotive, aerospace, industrial processes and a
s a welding professional, you are probably well versed in the common welding processes.
wealth of other demanding situations. There are four common welding
techniques are widely used in the welding industry, and the welding type selected will depend on the application and the parameters above. These are Gas Metal Arc Welding (GMAW or MIG); Gas Tungsten Arc Welding (GTAW or TIG); Shielded Metal Arc Welding, and Flux Cored Arc Welding. These types of arc welding join two pieces of metal with the assistance of an electric arc. This electric arc is formed between the metal part and an electrode on the gun. GMAW/MIG is the most accessible type
of welding to master. It is often used for welding stainless steel, copper, nickel, carbon steel, and aluminium. This type of welding is also best for lower-volume work, usually found in medium welding businesses. In this welding process, the wire electrode also acts as the filler metal to create the weld. It is constantly fed through the welding gun as it melts. MIG also uses shielding gas that comes in the form of carbon dioxide, oxygen, helium, or argon. This gas traveling through the welding gun is essential. It helps protect the molten pool of metal (weld pool) from environmental contaminants that
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can affect the quality of the weld. MIG welding is very popular and can join
metals of different thicknesses. It’s easy to learn and master, and the components needed to start welding are readily available. It has one of the best deposition rates, making it suitable for low, medium, and high-volume environments. Limitations of MIG welding include the
need for the shielding gas bottle that, depending on what gas you use, can be expensive. The positions you can weld with standard GMAW are also limited. However, the different types of transfer, short-arc, spray, globular, and buried arc, allow it to be more versatile. It’s also a difficult process to use outdoors because elements like wind can adversely affect it. Of all the welding techniques, GTAW
or Tungsten Inert Gas welding (TIG welding) is the most versatile and produces precise and neat welds. It uses a tungsten electrode to supply the current to the welding arc. Using gas shielding it is widely used for welding aluminium and magnesium, but can also be used to weld metals such as copper, copper alloys, nickel alloys, and stainless steel. This welding process found uses
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