Photographic evidence is presented which shows that there is produced in the critical range a large number of small carbon spots throughout the ferrite matrix. Since the spots are not present above the range or in pearlite or solid solution areas they are considered to be the result of the precipitation of carbon and ferrite at the iron-carbon eutectoid. The details of the mechanism of CO x CO2 acting as catalysts to break down cementite is presented from the standpoint of cementite being metastable. When this is the case a pressure gradient will exist for CO from the cementite toward the temper carbon and a similar gradient will exist for CO2 in the opposite direction. It is concluded that the gases do not transport carbon from cementite to the primary temper carbon spots under ordinary conditions of graphitization.
Proceedings of the Iowa Academy of Science
©1924 Iowa Academy of Science, Inc.
Flanders, H. E. and Hayes, Anson
"Structural Evidences of an Iron-Carbon Eutectoid,"
Proceedings of the Iowa Academy of Science, 31(1), 278-278.
Available at: https://scholarworks.uni.edu/pias/vol31/iss1/60