1983 Volume 69 Issue 8 Pages 913-920
The solubility of nitrogen in liquid chromium and chromium-iron alloys has been studied by a sampling method at the temperatures of 1550°1780°C and under 0.041.0 atm of nitrogen.
The free energy of solution and the activity of nitrogen in liquid chromium and chromium-iron alloys were determined by applying the interstitial model for the experimental results.
The results obtained are summerized as follows:
(1) Nitrogen dissolved in liquid chromium and chromium-iron alloys upto 50% Fe does not obey Henry's law, and solubility of nitrogen in liquid chromium is given by the following equation.
log K(Z)=5515/T-3.193, K(Z)=aN/√PN2=ψNZN/√PN2
(2) Activity coefficients of nitrogen based on pure liquid chromium are expressed as follows :
log ψNN(cr)=(4235/T-1.513)·YN YN<0.21
log ψFeN(cr)=1.80·YFe YFe<0.7
(3) Activity coefficients of nitrogen in iron-chromium alloys based on pure liquid iron are shown by the following equations :
log γcrN(Fe)=(-13765/T+3.10)·XCr Xcr<0.16
log fcrN(Fe)=(-148/T+0.033)·[%Cr] [%Cr]<15
Where YN and ZN are the mole ratio and the lattice ratio of nitrogen in liquid metal respectively.