直流エレクトロスラグ再溶解時の酸素の挙動について

抄録

By the use of a small scale unit for the DC-electroslag remelting, pure iron and carbon steels, S55C and SK3, were investigated with slags CaF₂, CaF₂-20%Al₂O₃ and CaF₂-20%CaO.
The results obtained are as follows:
1) Oxygen concentrations of ingots remelted in CaF₂ slag were measured, when iron electrode wasconnected positive, DCRP, and negative pole, DCSP. Based on the difference of oxygen concentrations, about 50% of oxygen, which was transfered from the slag into the molten metal at the tip of theelectrode, was eliminated through the slag/metal boundaries of molten pool and falling drop at DCRP.
2) Ratios of O^2- and AlQ₃^3- ions as oxygen carriers from slag to metal could be estimated for boththe polarities by the comparison of oxygen concentrations in ingots remelted in the CaF₂ and CaF_2-Al₂O₃ slags. The elimination of Al₂O₃ in the molten metal at the tip of the electrode through the slag/iron boundaries of falling drop and metal pool was estimated to be about 50%.
3) The elimination of elements must be discussed on the basis of the difference between cleanliness (a mass transfer from metal phase into slag phase) and contamination (a transfer of reverse direction).The former is not affected by the scale of remelting, but by slag composition and boundary conditions.The later, however, is related closely with the scale of units, i. e, the current density.