Thermodynamics of the iron-carbon-zinc system

• Published in: Metallurgical and materials transactions. B, Process metallurgy and materials processing science Process metallurgy and materials processing science, 1994-08, Vol.25 (4), p.569-578
• Main Authors: Luo, Wenzhong, Schlesinger, Mark E.
• Format: Article
• Language: English
• ISSN: 1073-5615; 1543-1916
• DOI: 10.1007/BF02650077

A two-zone isopiestic experimental technique was used to determine the solubility of zinc vapor in liquid and solid iron)carbon alloys as a function of Zn partial pressure (0.1-1 atm), C content (0-4.6 wt.%), and temperature (1473-1873K). The solubility of Zn at a given partial pressure decreases with both increasing temperature and C content in both liquid alloys and solid austenite; its activity in these solutions, and in pure delta -ferrite, deviates more positively from ideality than previous model-based predictions have suggested. The Bale)Pelton unified interaction parameter formalism was successfully applied to the results of liquid-alloy experiments, but the degree of experimental scatter in the austenite equilibrations was too great to allow its application in the calculation of solid-solution Fe)C)Zn thermodynamic parameters. Using the available results, values were calculated for the equilibrium partition coefficient K sub Zn in solidifying Fe)C alloys as a function of alloy C content; the results suggest that significant segregation of Zn between solid and liquid phases is not likely.