Measurement of the Anode Spot Temperature of a Plasma Arc Discharge

Abstract

The temperature distribution over the melt surface in an anode spot is measured during plasma arc heating of a metal at a pressure of 10 and 0.1 MPa in an argon atmosphere by a spectral method. The measurements are performed in the wavelength range where the discharge continuum intensity is minimal (240–450 nm). The spectral regions that are free of lines (340, 440 nm) are chosen to determine the anode (melt) and cathode (tungsten) temperatures. The tungsten cathode temperatures are 3160 and 3317 K at a discharge current of 150 and 220 A, respectively, and a pressure of 10 Pa. At a discharge current of 150 A, the maximum iron melt surface temperature in an anode spot is 3031 K. At a pressure of 0.1 MPa and 225 A, the maximum temperatures at the iron, tungsten, zirconium, and nickel melt surfaces are 2960, 4120, 4040, and 3590 K, respectively.