抄録
The equilibrium relation of the phase separation in the Fe-Cu-B system is investigated more in detail at the lower boron content at 1873K. By combining the Taylor series equation proposed by Wagner and that of the quadratic formalism proposed by Darken, the thermodynamic interaction parameters of copper and boron in molten iron are derived. As a result, it is confirmed that two liquid phases separation occurs even at the lower boron content in iron, [mass%B](in Fe)=0.006. The interaction parameters of copper and boron in molten iron at 1873K are derived.
