Abstract
ESR experiments were made to study the dephosphorization of S45C, SUS304, and 25% Cr steels with Ca-CaF2melt used as an electroflux. The reaction was found to occur mainly at the electrode-tip/Ca-CaF2melt interface. The distribution of P between the liquid steel and the Ca solution was determined only by the Ca content of CaF2 melt, irrespective of the remelting rate, the flux weight, and the P content of electrode studied. For SUS304 and 25% Cr steels the distribution ratio was given as follows:
(%P) / [%P] =4 (%Ca) (%Ca) 2
For S45C steel the ratio appeared to be larger than that expected from the above equation. The experimental results indicate that the dephosphorization reaction is nearly completed during the remelting process.
The observed dependence of the distribution ratio on the Ca content was proved to be consistent with a model for Ca-CaF2 solution in which an equilibrium for the reaction, 2Ca+++2e=Ca2++, is assumed.
