In carbon arc welding, the process of welding is carried out by an electric arc. The arc formed between the electrode and the workpiece generates high amount of heat. In
D.C. electric supply, the carbon electrode is connected to the negative terminal and the positive terminal is connected to the workpiece. During the formation of the electric arc, the temperature of the positive terminal is 4000°C and the negative terminal will be around 3000°C. Carbon, the electrode material will not fuse with the workpiece materials. This prevents the joint from becoming weak. A lengthy arc produces Carbon-monoxide at the location of welding and prevents the molten metal from reacting with the atmospheric air.
Both ferrous and non-ferrous metals can be welded by this method. Steel sheets, copper and its alloys, brass and aluminium parts are welded using carbon arc welding. This method of welding can also be done automatically. Starting of the electric arc is easy and the temperature is controlled easily. The disadvantage of this method is the presence of blow holes in the joint.