Abstract：Based on the calcium treatment for SPHC steel during the CSP production in Masteel，the equilibrium reactions for S-Ca and Al-Ca are calculated according to thermodynamic equilibrium model．It is concluded that the CaS is easy to precipitate in a relatively higher sulfur content and a lower temperature．At 1 873 K，theoretical calcium aluminum ratio to form liquid C12A7 and C3A after modification should make the ratio of w(［Al］)2/w(［Ca］)3 no more than 2.90×105 and 9.62×103，respectively. By reference to the actual production data，through the analysis it is proposed that the ratio of w(［Al］)2/w(［Ca］)3 should be no more than 5.0×104，the ration of w(［Ca］)/w(［Al］) should be in the range of 0.09-0.11 and the w(［S］) should be equal to or less than 0.003% during the calcium treatment.
2017, Vol. 27 
