The rates of hydrogen desorption from liquid iron and several liquid binary iron alloys were measured by the carrier gas method using argon. The results obtained are summarized as follows.
1. The rate of hydrogen desorption from liquid iron is governed by a first order reaction for hydrogen content in iron.
2. The rate of reaction is largely affected by the agitation of liquid iron.
3. The activation energy of the reaction obtained is a fairly low value of 5.7 kcal/mol.
4. From the facts mentioned above, the rate of hydrogen desorption from liquid iron is controlled by the transport of hydrogen atoms in the boundary layer of the liquid phase, and the value of mass transfer coefficient in the inductively stirred melt is 3.16 × 10
-2 cm/sec for pure iron at 1600 °C.
5. As the effect of alloying elements, the reaction rate decreases with carbon and chromium contents, and increases with silicon content. Nickel has no measurable effect.
6. A good correlation was found between the present values of mass transfer coefficients of hydrogen in the alloy systems and the diffusion coefficients of hydrogen in iron alloys reported by H. Bester and K. W. Lange.
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