Welding and Fabrication

MMA – Manual metal arc (MMA) welding is a welding process where the electric arc burns between a coated electrode and the workpiece. The electrode is fixed in an electrode holder and touches shortly the area that is to be joined. A short circuit is produced and the arc starts when lifting the electrode. During the welding process the electrode and its coating melt and slag develops above the weld seam.

MIG – Metal inert gas (MIG) welding is the process of making a weld with a wire electrode and a workpiece metal. An electric arc (powered by an electric arc generator) forms between the wire and the metal to heat both components to the point of melting. In this process, a shielding gas is fed through the welding gun to protect the wire from contaminants in the air, allowing for a purer weld free of oxidization.

MAG – Metal Inert Gas (MIG) / Metal Active Gas (MAG) welding refers to a group of arc welding processes that use the heat generated by a DC electric arc to fuse the metal in the joint area. A continuous electrode (the wire) is fed by powered feed rolls (wire feeder) into the weld pool.An electric arc is created between the tip of the wire and the weld pool. The wire is progressively melted at the same speed at which it is being fed and forms part of the weld pool. Both the arc and the weld pool are protected against atmospheric contamination by a shield of inert (non-reactive) gas.

TIG – Tungsten Inert Gas (TIG) welding is a strategy that involves using a tungsten electrode to heat the metal that is being welded. To protect the weld from contamination during the process, shielding in the form of inert gas, like argon, is used and can be used for any metals/thicknesses. TIG welding is highly regarded because of its quality and applicability. Indeed, the process can be applied to more metals than any other method, capable of welding metals like steel, bronze, nickel, brass, copper, magnesium, aluminum and gold.

Welding in a TIG operation is very precise and clean, allowing for a superior appearance. This is because a welder can increase and reduce the amount of heat that is used in the process, by means of a foot pedal, in order to better control the weld. In terms of cleanliness, TIG welding doesn’t result in sparks or create smoke and fumes.

SAW -This is a well established and extremely versatile method of welding. Submerged-arc welding (SAW) involves the formation of an arc between a continuously fed electrode and the workpiece. A blanket of powdered flux, which generates a protective gas shield and a slag (and may also be used to add alloying elements to the weld pool), protects the weld zone. A shielding gas is not required. The arc is submerged beneath the flux blanket and is not normally visible during welding

FCAW – Flux-cored arc welding (FCAW or FCA) is a semi-automatic or automatic arc weldingprocess. FCAW requires a continuously-fed consumable tubular electrode containing a flux and a constant-voltage or, less commonly, a constant-current welding power supply. An externally supplied shielding gas is sometimes used, but often the flux itself is relied upon to generate the necessary protection from the atmosphere, producing both gaseous protection and liquid slagprotecting the weld. The process is widely used in construction because of its high welding speed and portability.

GFCAW – While self-shielded FCAW still is used for field fabrication, gas-shielded FCAW is used predominantly for in-house fabrications. The quality of the weld, higher efficiency, and welder appeal can make up the cost of shielding gas.

Orbital welding is a specialized area of welding whereby the arc is rotated mechanically through 360° (180 degrees in double up welding) around a static workpiece, an object such as a pipe, in a continuous process. The process was developed to addresses the issue of operator error in gas tungsten arc welding processes (GTAW). In orbital welding, computer-controlled process runs with little intervention from the operator.[1] The process is used specifically for high quality repeatable welding.