A carbon arc cutting process variation that removes molten metal with a jet of ail: See STANDARD WELDING TERMS.
The air carbon arc cutting process uses an arc to melt metal which is blown away by a high-velocity jet of compressed air. The electrodes are rods made from a mixture of graphite and carbon, and most are coated with a layer of copper to increase their current-carrying capacity. Standard welding power sources are used to provide the current. Air is supplied by conventional shop compressors, and most applications require about 550 kPa (80 psi) at between 560 to 840 liters/min (20 to 30 cubic feet per minute), Manual rod holders are very similar in appearance to shielded metal arc welding electrode holders, and supply both compressed air and current.
In gouging operations, the depth and contour of the groove are controlled by the electrode angle, travel speed, and current. Grooves up to 16 mm (5/8 in.) deep can be made in a single pass. In severing operations, the electrode is held at a steeper angle, and is directed at a point that will permit the tip of the electrode to pierce the metal being severed.
In manual work, the geometry of grooves is dependent on the cutting operator’s skill. To provide uniform groove geometry, semiautomatic or fully automatic torches are used to cut “U” grooves in joints for welding, When removing weld defects or severing excess metal from castings, manual techniques are most suitable.
Voltage controlled automatic torches and control units are used for very precise gouging, with tolerances of less than 0.8 mm (1/32 in.), and are generally mounted on standard travel carriages.
Reference: American Welding Society. Welding Handbook, Vol. 2, 8th Edition. Miami, Florida: American Welding Society, 1991.