3322.     TAMMANN, G.  [Transformation of Cementite at 210°.]  Stahl u. Eisen, vol. 42, 1922, pp. 772-775; Chem. Abs., vol. 16, 1922, p. 3847.

        Lack of linear change of properties in steel with C content raises the question whether primary cementite and pearlitic cementite are the same kind of crystals.  In order to answer this question the transformation point of the 2 kinds is studied and found to be the same; the difference of the 2 kinds of cementite is, accordingly, one of grain size.  In the discussion this conclusion is confirmed as a result of X-ray analysis of the 2 kinds of cementite.