3070.     SCHENCK, R., AND MEYER, K.  [Studies of Carbides by the Methane Synthesis Method.  II.]  Ztschr. anorg. Chem. vol. 239, 1938, pp. 161-179; Chem. Abs., vol. 32, 1938, p. 8900.

        Carbonization of Mn and CH₄ is studied in the temperature range 700°-970°.  CH₄:H₂ equilibrium measurements indicate a change of state at 740° and 955°.  Below 740°, Mn₃C is not present as a pure compound, though solid solutions of this compound appear.  Mn₄C exists in a metastable state between 700° and 750°.  Above 750° and up to 950° Mn₃C exists independently.  It can take up more C to form a solid solution phase whose saturation limit at 970° is about 9% C.  In the range 750°-950°, the saturation limits of a solid solution phase poorer in C could be determined.  Appreciable differences from the conclusions of Vogel and Döring (abs. 3570) in the number and limits of the phase fields are indicated.