抄録
Kinetics of nitrogen desorption reaction of liquid iron and steel has been investigated by means of blowing various gas on the surface of the melt.
The nitrogen desorption reaction of liquid iron is of second order, and the reaction rate is remarkably affected by oxygen content in liquid iron.The rate constant decreases in inverse proportion to the second power of oxygen content above 0.03%, increases gradually below this value of oxygen content and tends to approach a constant value below 0.01% of oxygen.
From the standpoint of chemisorption of nitrogen atoms on the surface of liquid iron, these results lead to the conclusion that the rate-controlling step is the reaction between these atoms, which is disturbed by adsorbed oxygen atoms.
The activation energy of nitrogen desorption reaction is 39 kcal/mole in liquid iron containing oxygen less than 001%.
When the decarburization and the nitrogen desorption reactions proceed simultaneously by blowing argon and oxygen mixed gas to liquid steel, the latter reaction is deviated from the second order, and its rate becomes considerably slow in comparison with that of liquid iron by blowing only argon. These facts are considered to be caused by the disturbance of the reaction of nitrogen atoms by the oxygen atoms adsorbed on the surface of liquid steel.
