194.    BENESCH, F.  [Stability of Complex Iron-Manganese Carbides.]  Anyagvizsgálók Közlönye, vol. 19, 1941, pp. 1-30; Chem. Zentralb, 1942, I, pp. 1180-1181; Chem. Abs., vol. 37, 1943, p. 2322.

                  Investigates the stability of complex Fe-Mn carbides in the austenitic 12 and 20% Mn steels (1.1% C).  Annealed for a long time at 650°-850°, the free Fe-Mn carbides lose their homogeneity and change their structures similar to the hypereutectoid-carbon steels at corresponding temperatures.  In the case investigated, the hardness and, therefore, the number of precipitated double carbides are a direct function of time and temperature.  In the range of carbide precipitation hardness increases steadily; at 650°-850° the double carbides decompose, and in spite of water quenching, hardness decreases and ductility increases.  The magnetic properties missing in austenitic steels are also absent in the pearlitelike arrangements of the Fe-Mn carbides despite the fact that pearlite of straight carbon steel is magnetic.