Rate of Hydrogen Absorption in Liquid Iron and Effect of Dissolved Oxygen

Abstract

The rate of hydrogen absorption in the liquid iron stirred inductively were measured by the Sieverts method at constant pressures. The present measurement was carried out under a small interfacial area between the gas and iron melt by using a doughnut-shaped alumina plate on the melt in a narrow crucible.
The results show that the rates of hydrogen absorption are represented by the 1st order reaction and proportional to the square root of hydrogen pressure. The mass transfer coefficients, k_H, of hydrogen into liquid iron under the present inductive stirring could be calculated as (19±1). 10^-2cm/sec at 1600°C. This value was somewhat higher than those obtained by the literature probably because of the strong inductive stirring. It was found that it was also proportional to the 2/3 power of the diffusion coefficient, D^H, of hydrogen in liquid iron.
The effect of dissolved oxygen on the hydrogen absorption seemed to be negligible in the range of low oxygen contents of below 0.039% oxygen. The poisoning effect of surface active oxygen on the nitrogen transfer had been observed, but the similar effect was found in the case of hydrogen absorption.