The carbon arc welding is just similar to metal arc welding. The difference of the both welding electrode are different . In this welding process, the electrode is having carbon material (Carbon rod)and it consist of negative pole and work piece as positive pole. The arc is produced to heat the metal to melt temperature. In this heat temperature in negative electrode as 2800⁰c and positive electrode as 3800⁰c.
The carbon electrode using as negative pole because of low temperature generated on the tip than work piece, and carbon electrode not fuse and mix up with the work piece. If happens, the weld will be rich in carbon, and consequently more brittle and consumed excessively. In this reason DC current used in carbon arc welding AC current not used in the welding because of fixed polarity can be maintained.
The weld is best for joint of two metal melted without of addition of filler metal. If need the filler metal in welding process, the welding rod as in oxyacetylene weld. Sometime, portion gas used in welding process because of protection of molten metal from atmospheric oxygen.