The effect of arc velocity on cold electrode erosion

Results of experimental investigations of copper cathode erosion in a magnetically driven arc versus arc rotation velocity v are presented. The erosion rate measurements were carried out with the arc burning in air, for magnetic induction values B in the range of 0.005-0.386 T, axial air gas velocity of 7.65 ms-1, and current of 292 A. It is shown that in the range of small values of v and B, the mass erosion rate diminishes with v and B. Then, the erosion remains constant for a certain range of v and B, and, subsequently, begins to grow. This information is very important for the correct use of magnetic fields to decrease erosion in arc heaters