黒鉛の溶鉄への溶解速度におよぼす硫黄および燐の影響

抄録

The influence of sulfur or phosphorus on the rate of carbon dissolution from rotating graphite cylinders into the liquid iron alloys was studied in the temperature range of 1573-1773 K. Electrode-grade graphites (graphitizing and non-graphitizing carbon) were used. The results are summarized as follows:
(1) Non-dimensional correlation between mass transfer of carbon in the Fe-C melt and the rotational speed was obtained, which was expressed as
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\ oindentWhen sulfur or phosphorus was added, the results deviated from this correlation, which was interpreted in terms of mixed control of mass transfer and interfacial kinetics.
(2) Phosphorus decreased the overall mass transfer coefficient k, which was presumed to be due to the effect of phosphorus adsorption through its influence on the interfacial kinetics. The dependence of k on the structure of graphite was found to be negligible.
(3) Sulfur decreased k more than phosphorus, which suggested the more intensive surface activeness of sulfur. Particularly in the case of non-graphitizing carbon, k extremely diminished. This result would be attributable to the greater degree of adsorption of sulfur on non-graphitizing carbon than the graphitizing carbon.