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. (C) 2004 American Institute of Physics.1131214121