Activity of Sulphur in Liquid Iron Alloys

Abstract

The effect of alloying element on the activity coefficient of sulphur in liquid iron has been studied by equilibrating liquid iron alloy with the H₂-H₂S gas mixture at 1550°C in a resistance furnace.
The results obtained show that the elements such as C, Al, Si, P, Mo and W increase the activity coefficient of sulphur, while V, Cr and Nb decrease as follows:
log f ^C_S=0.12[%C] C<3%
log f ^A1_S=0.041[%Al] Al<7%
log f ^S1_S=0.075[%Si] Si<7%
log f ^P_S=0.035[%P] P<9%
log f ^V_S=-0.019[%V] V<11%
log f ^Cr_S=-0.011[%Cr] Cr<15%
log f ^Ni_S=0.0
log f ^Nb_S=-0.013[%Nb] Nb<12%
log f ^Mo_S=0.006₄[%Mo] Mo<20%
log f ^W_S=0.011[%W] W<15%.