2271.     MICHEL, A., AND BERNIER, R. [Thermomagnetic Study of Cementite Stability.]  Rev. mét., vol. 46, 1949, pp. 821-824; Chem. Abs., vol. 44, 1950, p. 1868.

        Cementite was prepared by passing a mixture of CO and 2 H₂ over spectroscopically pure Fe oxide held at 560°-1,000°.  Thermomagnetic analysis of this Fe₃C showed its Curie point at 210° and its comparative stability under conditions of thermal testing.  About 1/3 of cementite is graphitized when heated for 15 hr. in vacuum at 825°, and heating at 900° destroys 2/3 of it.  Heating both in H₂ and in N₂ rapidly decomposes this cementite.