Unveiling the Sparks: Exploring the Essence of Arc Welding

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Arc welding is a type of welding process in which an  arc generates heat to melt and join metals. The power supply uses direct current (DC) or alternating current (AC) to create an  arc between a consumable or non-consumable electrode and the base material. 

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How does it work? 

Arc welding is a  welding process used to join metals.The arc from an AC or DC power source generates intense heat of approximately 6500°F that melts the metal at the joint between the two parts. 

The arc can be  manually or mechanically guided along the weld line  while the electrode  simply conducts or conducts electricity by melting into the weld pool, thus supplying the  filler metal to the joint. 

Because  metals chemically react with oxygen and nitrogen in the air when heated to high temperatures by arc heating, shielding gases or slag are used to minimize exposure of the molten metal to air. On cooling, molten metals solidify and form a metallurgical bond. 

What are the different types of arc welding?

This process can be divided into two different types; Methods for consumable and non-consumable electrodes. 

Consumable electrode processes 

Metal Inert Gas  (MIG) and Metal Active Gas  (MAG) welding 

Also known as Gas  Arc Welding (GMAW),  shielding gases are used to protect  base metals from contamination. 

Protective Arc Welding (SMAW) 

Also known as Manual Metal Arc Welding (MMA or MMAW), Flux Protected Arc Welding or MMA welding is a process in which an electric arc burns between a metal rod (flux-coated electrode) and the part to be welded when welding the rod and the surface of the part merge into a molten pool. The simultaneous melting of the flux coating on the rod creates gases and slag that protect the weld puddle from the surrounding atmosphere. It is a versatile process that is ideal for joining ferrous and non-ferrous materials over a  gauge range  in all positions.

Flux-Cored Wire (FCAW) 

Developed as an alternative to the SMAW, the FCAW uses a DC-fed flux  electrode and a constant-voltage power supply to maintain a constant arc length. In this method, shielding gas or flow generated gas is used only for protection against contamination. 

Submerged Arc Welding (SAW) 

A common process using a  consumable electrode that is continuously energized and a consumable flux shield that becomes conductive when molten and provides a current path between the workpiece and the electrode. The flux also prevents spatter and sparks while suppressing fumes and ultraviolet radiation. 

Electro Slag Welding (ESW) 

Vertical process for welding thick plates (over 25mm) in one pass.ESW is based on an  arc starting before the addition of flux quenches the arc. The flux melts when the fuse wire  is inserted into the molten puddle, causing molten slag to form above the puddle. The heat required to melt the wire and sheet metal edges is generated by the resistance of the molten slag to the passage of electrical current. Two water-cooled copper feet monitor the process  and prevent the molten slag from escaping. 

Arc Stud Welding (SW) 

Similar to arc welding, SW joins a nut or fastener, usually  a flange with tabs that fuse together to form a joint, to another metal component.

Non-Consumable Electrode Processes 

Tungsten Inert Gas Welding (TIG) 

Also known as Gas Tungsten Arc Welding (GTAW), uses a non-flammable tungsten electrode to create the arc and an inert shielding gas to protect the weld and weld pool from air pollution 

Plasma Arc Welding (PAW) 

Like TIG, PAW uses an  arc between a non-consumable electrode and an anode in the torch body. The  arc ionizes the gas in the torch and creates plasma, which is then forced through a fine  hole in the anode to  the base plate. This separates the plasma  from the protective gas.