Nitrogen desorption in molten stainless steel for AISI 304 and 316 has been investigated by immersion argon blowing through an immersed alumina nozzle with 3mm in I.D.. Some kinetic parameter such as reaction order, rate constant and apparent activation energy of nitrogen desorption reaction for AISI 304 and 316 have been given out. Results show that (1) the correlation coefficients of regression straight line of second order reaction for nitrogen desorption reaction for stainless steel AISI 304 and 316 are most close to one. (2) Nitrogen desorption reaction from molten stainless steel for AISI 304 and 316 is the second order reaction. The rate constant at 1550℃ and 1580℃ for AISI 316 is respectively 0.08407 and 0.8237 wt%-1·min-1. The rate constant at 1550℃ for AISI 304 is 0.4166 wt%-1·min-1. (3) The apparent activation energy Ea of nitrogen desorption reaction for AISI 316 is 2136.47 kJ·mol-1. This huge value of apparent activation energy evidences that the nitrogen desorption reaction has a complex and multistep reaction mechanism. (4) The rate of nitrogen desorption reaction from molten stainless steel is mixed controlling by desorbing reaction of diatomic molecule nitrogen or monatomic nitrogen from molten metal at the gas-metal interface and the mass transfer in molten metal.

Nitrogen desorption in molten stainless steel for AISI 304 and 316 has been investigated by immersion argon blowing through an immersed alumina nozzle with 3mm in I.D.. Some kinetic parameter such as reaction order, rate constant and apparent activation energy of nitrogen desorption reaction for AISI 304 and 316 have been given out. Results show that (1) the correlation coefficients of regression straight line of second order reaction for nitrogen desorption reaction for stainless steel AISI 304 and 316 are most close to one. (2) Nitrogen desorption reaction from molten stainless steel for AISI 304 and 316 is the second order reaction. The rate constant at 1550℃ and 1580℃ for AISI 316 is respectively 0.08407 and 0.8237 wt%-1·min-1. The rate constant at 1550℃ for AISI 304 is 0.4166 wt%-1·min-1. (3) The apparent activation energy Ea of nitrogen desorption reaction for AISI 316 is 2136.47 kJ·mol-1. This huge value of apparent activation energy evidences that the nitrogen desorption reaction has a complex and multistep reaction mechanism. (4) The rate of nitrogen desorption reaction from molten stainless steel is mixed controlling by desorbing reaction of diatomic molecule nitrogen or monatomic nitrogen from molten metal at the gas-metal interface and the mass transfer in molten metal.