Abridgment of cathode energy of the iron arc

For purposes of study, the available energy at the cathode of the iron arc for welding in air, and the disbursement of this available energy to the cathode processes, are set up in balance-sheet form. The energy as heat at the cathode includes that from (1) ionic bombardment, (2) ohmic resistance of cathode tip, (3) radiation from the anode, and (4) combustion. Since the division of total arc energy between anode and cathode is nearly an equal one, the sum of the first three should approximate one-half of the total energy input to the arc. Heat Disbursement at Cathode: The principal consumption of heat at the cathode is by (5) melting of cathode, (6) evaporation of atoms at cathode, (7) evaporation of electrons at cathode, (8) dissociation of arc vapors, (9) radiation to anode and to air. Of the total heat disbursed by the arc more than half is consumed, as shown by measurement, by the melting of the electrode. The heat consumption for this melting is greater than the calculated value of total heat received at the cathode. The latter value is therefore incorrect and needs to be revised, using higher values of Vc or φ + or both. On the other hand, the calculated total energy consumption at the cathode corresponds closely to one-half the measured total electrical input to the arc and is therefore approximately correct.