285.    BOERICKE, F. S.  Equilibria in the Reduction of Chromium Oxide by Carbon, and Their Relation to the Decarburization of Chromium and Ferrochrome.  Bureau of Mines Rept. of Investigations 3747, 1944, 34 pp.; Chem. Abs., vol. 38, 1944, p. 3539.

                 Reduction of Cr2O3 by C involves 4 distinct reversible-reaction steps:  (1) 3Cr2O3+13C=2Cr3C2+9CO; (2) 5Cr2O3+27Cr3C2=13Cr7C3+15CO; (3) 5Cr2O3+14Cr7C3=27Cr4C+15CO; (4) Cr2O3+3Cr4C=14Cr+3CO.  Describes apparatus and methods for measuring equilibria in these reaction steps, and thermodynamic values for each reaction are derived from equilibrium and requisite auxiliary-thermal data.  The resulting thermal properties of the Cr carbides show that each carbide is stable with respect to dissociation into the other 2 carbides.  A theoretical consideration is given of the decarburization of Cr and ferrochrome by Cr2O3, Fe3O4, H2, and Si.  Cr2O3 is an effective decarburizing agent at 2,000°, particularly if means are furnished for operating under low CO partial pressures.  Magnetite, theoretically, is a more effective decarburizer than Cr2O3, but in practice the rapid exchange of Fe in the refining agent with Cr in the metallic phase results in about the same net effectiveness as for Cr2O3.  Both H2 and Si are unsatisfactory agents for decarburizing Cr or ferrochrome.

         -------------- See abs. 1729.

                 BOGOYAVLENSKAYA, A. N.  See abs. 1806.

                 BOGROW, A.  See abs. 2174.

                 BOGUSLAVSKI, I. M.  See abs. 1671.

                 BÖHM, H.  See abs. 1711, 1713, 1717.

                 BÖKMANN, J.  See abs. 3052, 3053.

                 BOLLHORN, A.  See abs. 1504.

                 BOLTUS-GORUNEANU, M.  See abs. 659.