854.    EVANS, H. P., AND HAYES, A.  Graphitizing Behavior of Iron Carbide in Pure Iron-Carbon Alloys in the Critical-Range.  Trans. Am. Soc. Steel Treating, vol. 11, 1927, pp. 691-707; Chem. Abs., vol. 21, 1927, p. 3878.

      Fe-C alloys of high purity have been graphitized in the presence of a CO-CO₂ gas mixture at a pressure of 5 atm. within the temperature interval 1,292°-1,875° F.  Fe₃C in Fe-C alloys of high purity and containing about 2.3% C is metastable at temperatures below 1,292° F. and above 1,562° F. in the presence of this CO-CO₂ gas mixture when it is applied at a pressure of 5 atm.

      EVANS, R. M.  See abs. 763.