Abstract
As a sequel to the previous report concerning the equilibrium among oxygen gas, FeO-Fe2O3 CaO-SiO2 slag and Fe-Si-O molten iron, in this report the statistical thermodynamic analysis is made of the equilibrium among oxygen gas, FeO-MnO-SiO2 slag and Fe-Mn-Si-O molten iron. The study of such system is reluted to the deoxydation by the use of Silicon and Manganese. This subject has been so far discussed.
The basic fluxes containing more MnO and CaO are recently put oo sale as a flused flux for the submerged arc welding. It is noted that the mechanical properties, especially the impact properties at low temperature, of the weld metals obtuined with use of these fluxes are fairly good. This repost does not give any definite answer, but it seems to serve as an aid in resear ches on this point.
As FeO-CaO-SiO2 calculated in the previous report is here replaced by FeO-MnO-SiO2 system, and also CaO replaced by MnO, both indicate similar tendency in equilibrium oxygen pressure, the amount reduced of silicon, and oxygen value in molten iron. CaO and MnO, both of which are basic, are considered to be almost similar.
The amounts of CMn, Csi and Co newly determined in the present calculation. In view of this calculation, it is necessary to check whether the common deoxydation by manganese and silicon is more effective than by only silicon. This problem requires further scientific investigations about various constants.
