3071.     SCHENCK, R., MEYER, K., AND MAYER, K.  [Carbide Studies in the Methane Synthesis.  III.]  Ztschr. anorg. Chem., vol. 243, 1939, pp. 17-31; Chem. Abs., vol. 34, 1940, p. 4974.

        Space isotherm for the Mn-Fe-C system at 800° was constructed by measuring displacements in the equilibrium, Mn+CH₄=MnC+2 H₂, at 760 mm.  The space model shows 4 zones of the compositions indicated:   A, containing (1) a field of β-Mn and a weak MnC phase, (2) a field of mixed crystals of γ-Fe, (3) a field of mixed crystals of β-Mn and γ-Fe; B, containing as its fundamental phases a univariant equilibrium γ-Fe and carbides of Mn; C, a univariant equilibrium containing Mn carbides; D, in which (Mn, Fe)₃C and a C-rich phase (7.4% C) prevail.  An alloy, 95% Mn+5% Fe, shows a maximum solubility of C (8.4%).  In the steel region, the isotherms of C show several small fields corresponding to various groups of Mn steels.