The thermodynamic behavior of sulfur in molten nickel and nickel-base alloys |
| |
Authors: | Wilfredo V Venal Gordon H Geiger |
| |
Affiliation: | (1) Technology Department, Stellite Division, Cabot Corp., Kokomo, Indiana;(2) Department of Metallurgical Engineering, University of Arizona, 85712 Tucson, Arizona |
| |
Abstract: | The thermodynamic properties of dilute solutions of sulfur in pure liquid nickel were investigated at 1500, 1550, and 1575°C
for sulfur concentrations up to 0.7 wt pct. Based on the infinitely dilute, wt pct standard state, the equilibrium data obtained
for the reaction: H2(g) + S = H2S(g) were fitted by the equations: logK = − 1489/T − 1.772, and ΔG° = 6812 + 8.11T, cal/mole. For the solution ofS
2(g) in pure Ni according to the reaction: 1/2S
2(g) = S (in Ni), the standard free energy of solution is found to be: ΔG° = - 28,342 + 3.62T, cal/mole. For the very dilute
solutions of sulfur normally encountered in nickel-base melting, the activity coefficient of sulfur in pure Ni at 1575°C is
given by: log fS= -0.035 (pct S). The effects of alloying elements normally used in nickel-base alloys on the activity coefficient of sulfur
in molten nickel were investigated. The activity coefficient of sulfur is increased by all of the alloying elements studied,
as evidenced by the interaction parameters: eS
fe = +0.005, eS
Cr = +0.030, eS
Mo = +0.053, eS
Ti = +0.160, and eS
A1 = +0.133. Measured values of the activity coefficient of sulfur in the quaternary system Ni-S-Cr-Fe agreed reasonably well
with those predicted from binary and ternary data.
This work constitutes a portion of the work performed by W. F. VENAL for the Ph.D. degree from the University of Illinois
at Chicago Circle.
Formerly Professor of Metallurgical Engineering at UICC. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|