What is ‘ARC Welding’?
Arc welding is a type of welding process using an electric arc to create heat to melt and join metals. A power supply creates an electric arc between a consumable or non-consumable electrode and the base material using either direct (DC) or alternating (AC) currents.
In simple, Arc-based welding is called arc welding.
How Does it Work? – arc welding
Arc welding is a fusion welding process used to join metals. An electric arc from an AC or DC power supply creates an intense heat of around 6500°F which melts the metal at the joint between two work pieces.
The arc can be either manually or mechanically guided along the line of the join, while the electrode either simply carries the current or conducts the current and melts into the weld pool at the same time to supply filler metal to the join.
Because the metals react chemically to oxygen and nitrogen in the air when heated to high temperatures by the arc, protective shielding gas or slag is used to minimize the contact of the molten metal with the air. Once cooled, the molten metals solidify to form a metallurgical bond.
WHAT ARE THE TYPES OF ARC WELDING?
- Consumable
- Non-Consumable
Consumable Electrode Methods
Metal Inert Gas Welding (MIG) and Metal Active Gas welding (MAG)
Also known as Gas Metal Arc Welding (GMAW), uses a shielding gas to protect the base metals from contamination.
Shielded Metal Arc Welding (SMAW)
Also known as manual metal arc welding (MMA or MMAW), flux shielded arc welding or stick welding is a process where the arc is struck between the metal rod (electrode flux coated) and the workpiece, both the rod and workpiece surface melt to form a weld pool.
Simultaneous melting of the flux coating on the rod will form gas, and slag, which protects the weld pool from the surrounding atmosphere. This is a versatile process ideal for joining ferrous and non-ferrous materials with a range of material thicknesses in all positions.
Flux Cored Arc Welding (FCAW)
Created as an alternative to SMAW, FCAW uses a continuously fed consumable flux cored electrode and a constant voltage power supply, which provides a constant arc length. This process either uses a shielding gas or just the gas created by the flux to provide protection from contamination.
Submerged Arc Welding (SAW)
A frequently-used process with a continuously-fed consumable electrode and a blanket of fusible flux which becomes conductive when molten, providing a current path between the part and the electrode. The flux also helps prevent spatter and sparks while suppressing fumes and ultraviolet radiation.
Electro-Slag Welding (ESW)
A vertical process is used to weld thick plates (above 25mm) in a single pass. ESW relies on an electric arc to start before a flux addition extinguishes the arc. The flux melts as the wire consumable is fed into the molten pool, which creates a molten slag on top of the pool. Heat for melting the wire and plate edges is generated through the molten slag’s resistance to the passage of the electric current. Two water-cooled copper shoes follow the process progression and prevent any molten slag from running off.
Arc Stud Welding (SW)
Similar to flash welding, SW joins a nut or fastener, usually with a flange with nubs that melt to create the join, to another metal piece.
Non-consumable Electrode Methods
Tungsten Inert Gas Welding (TIG)
Also known as Gas Tungsten Arc Welding (GTAW), uses a non-consumable tungsten electrode to create the arc and inert shielding gas to protect the weld and molten pool against atmospheric contamination.
Plasma Arc Welding (PAW)
Similar to TIG, PAW uses an electric arc between a non-consumable electrode and an anode, which are placed within the body of the torch. The electric arc is used to ionize the gas in the torch and create the plasma, which is then pushed through a fine borehole in the anode to reach the base plate. In this way, the plasma is separated from the shielding gas.
IS ARC WELDING EASY?
The arc, created by an electrical current between the base metal and the wire, melts the wire and joins it with the base, producing a high-strength weld with great appearance and little need for cleaning. MIG and flux-cored welding are easy to learn and can create extremely clean welds on steel, aluminum, and stainless.