The Alloys of Iron and Carbon Vol.I-Constitution by S.Epstein, McGraw-Hill Book Company, Inc. New York and London 1936.
Notes:
All available important published data, and some unpublished investigations on iron-carbon alloys, have been reviewed and correlated.
About the concept of the double diagram Epstein says the following:
"There is little clear-cut proof that the temperatures and compositions in the iron-graphite system vary markedly from those of the iron-cementite system. The location of the double lines is based on the greater stability of graphite, and as much upon theoretical grounds as upon experimental evidence.
For greater simplicity the behavior of the iron-carbon alloys might be explained solely on the basis of the iron-cementite diagram, omitting the iron-graphite diagram. The fact of graphitization might then be covered by the statement that cementite is unstable at high temperatures and at high carbon concentration, as for example in the upper right corner of the diagram towards D, and, therefore, decomposes to form graphite very easily."
