Manganese And Chromium Distribution Between Cao-sio_2-mgo_(sat.)-cro_(1.5)-mno Slags And Fe-cr-mn Stainless Steel

摘要

The Mn and Cr equilibria between a Mn rich stainless steelmaking slag (CaO-SiO_2-MgO_(sat.)-MnO-CrO_(1.5)) and Fe-Cr-Mn stainless steel were investigated in a temperature range from 1 823 to 1 873 K under Ar atmosphere. The partition ratios L_(Mn) and L_(Cr) between liquid slag and steel were determined as a function of slag composition and temperature. By combining the experimental results with thermodynamic calculations, it was found that, as basicity increases, L_(Mn) decreases, while L_(Cr) increases. The elevated basicity leads to a high MnO activity coefficient. On the other hand, the CrO_(1.5) activity coefficient decreases with higher slag basicities. The influence of MnO and CrO_(1.5) contents on the activity coefficients was also considered. It is concluded that in order to maximize Mn recovery during high Mn stainless steel production, a basic slag with a high MnO activity coefficient must be employed whereas high temperatures should be avoided.