Effect of Carbon Dissolution Reaction on Wetting Behaviour of Molten Fe–C Alloy on Graphite Substrate in the Initial Contact Period

摘要

A wetting behaviour of Fe–C sample on carbonaceous materials has been extensively investigated to understand the liquid flow behaviour in lower part of blast furnace. The previous studies reported a large change in apparent contact angle in the initial contact period in the wetting between the Fe–C sample and the carbonaceous materials substrate. The carbon dissolution reaction and the interfacial morphology in the initial contact period would strongly affect the wetting behaviour in this period. To further understand the wetting behaviour between the Fe–C sample and the substrate, the effects of the carbon dissolution reaction on the wetting behaviour in the initial contact period must be considered. Fe-3.70, 4.26, 4.90 mass% C samples were fabricated using a high-frequency induction heating furnace under an inert gas atmosphere. The graphite substrate was made from 99.90% pure graphite powder using a hot press furnace under an argon gas atmosphere. The wetting behaviour of the graphite substrate with molten Fe–C sample is investigated using a sessile drop method with a molten sample injection and quenching systems. The results shown that the apparent contact angles significantly decreased from the initial apparent contact angle. The carbon concentration of the carbon-unsaturated Fe–C sample gradually increased and reached the saturation after the 300 s of contact. The formation of concave was observed and developed in the initial contact period due to the transfer of carbon atoms into the carbon-unsaturated Fe–C sample. The wetting behaviour was dependent on interfacial energy of solid-liquid phases before the formation of concave. After the formation of concave, the wetting behaviour dominantly depended on interfacial morphology change.