Abstract
In order to clarify the effects of Ni and Cr on the Si deoxidation of liquid Fe–Cr–Ni alloy, the deoxidation equilibria of Fe–Ni and Fe–Cr–Ni alloys with Si were studied. The experiments were conducted on the conditions up to 20 mass% Ni in the Fe–Ni system and up to 18 mass% Cr and 9 mass% Ni in the Fe–Cr–Ni system at the temperatures of 1823, 1873 and 1923K. Results obtained were summarized as follows:
The effect of Ni on the interaction coefficient of Si was expressed by
log fSiNi = -0.009[%Ni] + 2×10-4[%Ni]2, [mass%Ni]≤20, 1823≤T≤1923K
The cross product terms concerning Cr and Ni on the interaction coefficients of Si and O dissolved in Fe–Cr–Ni alloy were expressed by
rSi(Cr, Ni) + 2rO(Cr, Ni) = –0.001, 1823≤T≤1923K
The deoxidation product K'Si = [%Si]·[%O]2 was numerically expressed by
log K'Si = 8.40 – 24600/T (1.40 – 3500/T)[%O]10.029[%Si] – (0.047 – 246/T + 4.3×10-4[%Cr])[%Cr]
– (0.003 + 2×10-4[%Ni])[%Ni] + 0.001[%Cr] [%Ni]
[mass%Cr]≤25, [mass%Ni]≤20, 1823≤T≤1923 K
