Carbon arc welding
Carbon arc welding (CAW) is a process which produces coalescence of metals by heating them with an arc between a nonconsumable carbon (graphite) electrode and the work-piece. It was the first arc-welding process ever developed but is not used for many applications today, having been replaced by twin-carbon-arc welding and other variations. The purpose of arc welding is to form a bond between separate metals. In carbon-arc welding a carbon electrode is used to produce an electric arc between the electrode and the materials being bonded. This arc produces extreme temperatures in excess of 3,000°C. At this temperature the separate metals form a bond and become welded together.
CAW could not have been created if not for the discovery of the electric arc by Sir Humphry Davy in 1800, later repeated independently by a Russian physicist Vasily Vladimirovich Petrov in 1802. Petrov studied electric arc and proposed its possible ways of usage, including for welding.
- Twin carbon arc welding (TCAW) in which the arc is established between two carbon electrodes
- Gas carbon arc welding (CAW-G) no longer has commercial significance. Other processes that use shielding gases have also replaced carbon-arc welding such as tungsten-arc welding (GTAW, or TIG), plasma-arc welding (PAW), and atomic-hydrogen welding (AHAW). Each of these processes, including carbon-arc welding, use a nonconsumable electrode. A filler metal is generally used to aid the bond in the workpieces.
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- Welding handbook Volume 2, eighth edition. Library of Congress number: 90-085465 copyright 1991 by American Welding Society