3669.     WESTGREN, A., AND PHRAGMÉN, G.  [X-Ray Studies on the Crystal Structure of Steel.]  Ztschr. physik. Chem., vol. 102, 1922, pp. 1-25; Jour. Iron Steel Inst. (London), vol. 105, 1922, pp. 105, 241-273; Engineering, vol. 113, 1922, pp. 630-634; Chem. Abs., vol. 16, 1922, p. 2291.

        X-ray photograms (according to Debye and Scherrer) of an Fe wire, heated to 800°, 1,100°, and 1,425° have shown that the wire within the so-called β- and δ-ranges has a body-centered cubic structure and within the γ-range a face-centered structure.  It is thus proved that the transformation that takes place at 900° (A3) is reversed at 1,400° (A4).  The γ-Fe lattice of austenite steels is enlarged by the dissolved C.  A steel with 1.98% C has a somewhat larger lattice when quenched from 1,100° than when quenched from 1,000°.  Also the a-Fe lattice in martensite seems to be influenced by the C present. The ranges of homogeneous a-Fe lattice in martensite seems to be influenced by the C present.  The ranges of homogeneous a-Fe lattice in martensite are extremely small.  A steel with 0.80% C, quenched in H2O from 760°, is on the verge of being totally amorphous.  Debye photograms of cementite and of the well-known crystal tables of spiegel Fe are identical.  A Laue photograph and investigations of an orientated rotating crystal of the latter type have made it possible to find out the crystal data of cementite.  It belongs to the orthohombic system, its ratio of axis is 0.760:0.755:1, and the dimensions of its elementary parallelpiped are 4.53, 5.11, and 6.77 Å.  The base group consists of 4 mol. Fe3C, which corresponds to a specific weight of 7.62 for the cementite.

        WESTRIK, R.  See abs. 677.