It is necessary to investigate the solution chemistry of the nonmetallic elements in iron to understand the chemistry of steelmaking. Most of these elements have an appreciable solubility in liquid iron, but may be separated from the iron by precipitation of an insoluble compound with another metal. They may also separate from the iron when the metal is cooled and solidified; in these circumstances an iron salt, or the salt of another metal may be formed. The distribution of a non-metallic element between such phases and what is still in solid solution may be described by an equilibrium constant that can be calculated from the free energy of formation of the compounds in the system. This procedure is the same as that used to describe solubility and precipitation phenomena in aqueous solution; however, since steelmaking involves temperatures in excess of 1500° C., the free energies of formation at these temperatures must be considered. Such calculations have not eliminated the need to examine and analyze precipitates in steel.
Proceedings of the Iowa Academy of Science
©1958 Iowa Academy of Science, Inc.
Duwell, Ernest J.
"Identification of Inclusions in Steel by Microradiography,"
Proceedings of the Iowa Academy of Science, 65(1), 208-219.
Available at: https://scholarworks.uni.edu/pias/vol65/iss1/29