Abstract
The interfacial tension between molten steel and slag was measured by the sessile drop method with transmission X-ray technique. The results were summarised as follows;
(1) The increase of oxygen content in steel caused the remarkable decrease of the surface tension of steel and the interfacial tension at steel-slag boundary. The fact shows that the oxygen dissolved in steel acts as the surface-active reagent at metal-slag boundary as well as at metal-gas interface.
(2) Consequently, the interfacial tension depended in most part on the oxygen content in steel and the effect of slag composition on the interfacial tension was not so much.
(3) In order to clear the effect of slag composition on the interfacial tension, the experimental results were discussed by the values of Δσ (=σm-σms) which indicated the differences between the surface tension and the interfacial tension at constant of oxygen content in metal. The values of Δσ dereased with increase of silica content in a slag.
(4) The work of adhesion between molten steel and slag Wad (=σm+σs-σms) was dependent sufficiently on the slag composition. The work of adhesion for a fluoride slag-steel system was smaller than that for an oxide slag-steel system, while the work of adhesion for oxide slag-metal system decreased with increasing of silica content in a slag.
