3516.     UMINO, S.  Specific Heat of Iron-Carbon System at High Temperatures, and the Heat Changes Accompanying Those in Phase.  Sci. Repts. Tôhoku Imp. Univ., 1st ser., vol. 23, 1935, pp. 665-793; Chem. Abs., vol. 29, 1935, p. 4253.

        Heat content of 19 Fe-C alloys containing 0.07-5.07% C was measured at numerous high temperature sup to and beyond the melting point.  Electrolytic Fe and sugar were used in preparing the melts.  The heat of fusion of the δ-alloy containing 0.03% C is 65.31 cal.; 0.07% C, 64.90 cal.; of the γ-alloy containing 0.13% C, 67.19 cal.; 1.70% C, 57.8 cal.  the heat of fusion of the eutectic is 60.91 cal.  That of cementite, by extrapolation, is 65.0 cal., its melting point being estimated to be 1,600°.  The heats of transformation of the a- into the γ-Fe at the A₃ point are calculated to be 5.59 cal. for pure Fe and 16.60 cal. for the eutectoid at 720°.  The heat of solution of Fe₃C in γ-Fe of 0.90% C is 11.15 cal. at 720°; it decreases with rise in temperature and C concentration.  The heat of the A₀ transformation of Fe₃C is estimated to be 9.35 cal.