MAIN GUIDELINES FOR PRODUCING HIGH NITROGEN STEELS USING THERMAL PLASMA
Faculty of Metallurgy and Materials Engineering, Technical University of Czestochowa Al. Armii Krajowej 19, 42-200 Czestochowa, Poland
The application of thermal plasma was intended to enable the introduction of the excess chemical potential of a non-equilibrium phenomenon in character, and the obtained nitrogen concentration in liquid metal is a stationary concentration.
A quarter-technical scale laboratory plasma furnace with a ceramic crucible and an operation pressure of up to 5 atm, constructed at the Steelmaking Laboratory of the Faculty of Metallurgy and Material Engineering was used in the experiments. Based on the investigation results, the model calculations of the energy-physical properties of the plasma arc, and on the assumptions resulting from the specialist literature on the subject, a semi-empirical model of saturating liquid steel with nitrogen using thermal plasma has been developed. Using this model, a technological prediction has been prepared.
The basic results of the investigations have enabled the authors to create the idea of a pilot installation for HNS steel production including the capability of complete saturation with nitrogen using a gas carrier in a single-stage process. The developed process has been briefly named the PPMP (Plasma Pressure Melting Process).