The activity of chromium in molten Fe-Cr-C alloy was measured at 1 823 K using chemical equilibration technique in the dilute Cr concentration region. It was found that chromium in Fe-Cr-C alloy showed Henrian behavior up to 3 mass% Cr and that the activity coefficient of chromium at infinitely dilute solution in Fe-Cr alloy was 3.90 at 1 823 K. The effects of carbon on the activity coefficient of chromium at infinitely dilute solution in Fe-Cr-C alloy could be expressed as follows; lnγC°r(S) = 1.29-7.09XC at 1 823 K There is little temperature dependence of the activity of chromium at carbon saturated condition. The standard Gibbs energy of mixing for Fe-Cr alloy and Fe-Cr-Csatd alloy was calculated using the Gibbs-Duhem relationship. The results indicated that the affinity between chromium is larger than that of chromium for iron in Fe-Cr alloy. But the affinity between chromium and carbon is increased with increasing carbon.
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry