Investigation of Kinetics of Absorption of Nitrogen by Highly Reactive Liquid Metals in Arc and Plasma Melting

摘要

Investigations were conducted to study kinetics of absorption of nitrogen by liquid vanadium, zirconium and titanium by the method of arc and plasma melting of metal within a temperature range of 2273 to 2873 K at a partial pressure of nitrogen ranging from 0.09 to 25 kPa. The investigations were performed by a specially developed procedure for direct measurement of metal temperature during melting using colour pyrometers. It was shown that the rate of absorption of nitrogen increased with an elevation of temperature, whereas the threshold concentration of nitrogen did not change compared with its absorption in a conventional oscillatory state (levitation melting). Besides, the rate of absorption of nitrogen was higher in plasma melting than in arc melting, which is associated with a higher energy activation of nitrogen molecules in the gas phase.