Abstract
A plasma torch and refractory-lined furnace with a 10 kg capacity were used to study the kinetics of nitrogen absorption and desorption in molten iron. In this study, melts containing both oxygen and sulfur were used. In accord with earlier studies, a limiting rate constant of 0.020 cm/s-pct was observed at high oxygen and/or sulfur contents. At lower oxygen and/or sulfur contents, the measured desorption rates are smaller than most of the reported values and appear to be limited by mixed melt, mass transfer chemical control. Absorption of nitrogen from the plasma arc is limited by mass transfer in the melt. The dominant form of convection in the vicinity of jet impingement is surface tension driven flow. The reaction N(g)=N(pct) appears to be responsible for the enhanced nitrogen content of the melt. The nitrogen content of a melt in equilibrium with the atomic nitrogen content of an Ar-5 pct N2 plasma jet was determined to be 0.30 wt pct or thirty times the equilibrium value.
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T. B. KING, formerly Professor of Metallurgy at the Massachusetts Institute of Technology, Cambridge, MA, is deceased.
This paper is based on a presentation made in the T.B. King Memorial Symposium on “Physical Chemistry in Metals Processing” presented at the Annual Meeting of The Metallurgical Society, Denver, CO, February, 1987, under the auspices of the Physical Chemistry Committee and the PTD/ISS.
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Katz, J.D., King, T.B. The kinetics of nitrogen absorption and desorption from a plasma arc by molten iron. Metall Trans B 20, 175–185 (1989). https://doi.org/10.1007/BF02825598
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DOI: https://doi.org/10.1007/BF02825598