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 1483.    HONDA, K., AND MURAKAMI, T.  Thermomagnetic Properties of the Carbides Found in Steels.  Sci. Repts. Tôhoku Imp. Univ., vol. 6, 1917, pp. 23-29; Chem. Abs., vol. 11, 1917, p. 2887.

        To obtain the carbides, rods of C and W steels were annealed at 880°-920° and cooled very slowly.  The rods were then polished and turned down until they were 7 mm. thick and 10 cm. long.  The rods were used as anodes in dilute HCl, and by electrolysis the carbides were obtained.  The Fe cementite was obtained as a gray powder and the double carbide as a black powder. The former contained 6.08% C and 93.5% Fe; the latter 8.10% C, 31.71% Fe, and 53.70% W.  The Fe cementite is ferromagnetic and in a field of 500 gauss its specific magnetization is 19.7.  The critical temperature, above which the carbide is paramagnetic, is 215°.  In its free state the cementite is decomposed almost completely into its components by heating long enough at 900°.  The double carbide found in low W-steels also is ferromagnetic, and its specific magnetization in a field of 500 gauss is 15.5.  Its critical temperature lies at 400°.  It is decomposed into its components by heating it to 850°.  The conclusion, however, may not apply to the double carbide as it exists in low-W steel because its boundary condition is quite different in the steel than when existing by itself in the free state.