Effects of Pressure and Inert Gas Top Blowing on the Rate of Molten Steel Hydrogen Desorption

Abstract

The rate of hydrogen desorption from liquid steel bath was measured to investigate the effect of pressure. Experiments of hydrogen desorption from molten steel were conducted using 30kg and 100kg scale induction furnace. Hydrogen desorption reaction was basically controlled by gas phase mass transfer over 1.4 kPa in this experimental condition. The effect of argon gas top blowing on to the free surface of molten steeel bath on the gas phase mass transfer coefficient was evaluated. Following dimensionless equation was obtained, assuming 0.33 power of Sc.
Sh(H/d_n)=0.002Re^0.88Sc^0.33(H/d_c)^1.39
where H is the distance between free surface of melt bath and nozzle, d_n, is inner diameter of nozzle, d_c is inner diameter of crucible, Sh= k_Gd_n/D _Ar-X, Re=u_gd_n/ v_g, Sc = V_g/D_Ar-X, k_G is mass transfer coefficient of gas phase, D_Ar-X is diffusion coefficient of diffusing gas, u_g is gas velocity, v_g is kinetic viscosity of gas.