88.     ARNOLD, J. O., AND READ, A. A.  Conditions in Which Carbon Exists in Steel.  Proc. Chem. Soc., 1894, pp. 105-106; Jour. Soc. Chem. Ind., 1894, p. 740.

                Existence is confirmed of a carbide of Fe having the formula Fe₃C.  The normal carbide exists in 2 different forms identical in chemical composition – a diffused carbide consisting of granules or very small plates and a crystalline carbide arranged as plates and consisting of pure Fe₃C.  The % of total C obtained as carbide is greater in hard than in soft steels.  This loss is due to the presence of a readily decomposed subcarbide of Fe existing to the extent of about 25% in mild steel and capable of existing to the same amount in cold, hard steel after the latter has been heated for sometime at a white heat.