3228.     SMOLUCHOWSKI, R.  Diffusion Rate of Carbon in Iron-Cobalt Alloys.  Phys. Rev., vol. 62, 1942, pp. 539-544; Chem. Abs., vol. 37, 1943, p. 819.

        Studies of rates of various transformations and reactions in Fe alloys seem to indicate that certain elements have a definite effect on the rate of diffusion of C in γ-Fe.  In particular, Co shows a pronounced accelerating effect.  By direct measurement of the rate of diffusion of C in Fe-Co alloys, this conclusion is confirmed, and an increase in the diffusion coefficient is established.  An addition of 4% Co decreases the activation energy from 32,500-30,000 cal., corresponding to an almost twofold increase of the diffusion rate at 1 at. % C concentration.  At higher C contents, the accelerating effect of Co is smaller.  This property of Co is unusual, especially in view of the fact that both Mn and Ni are known to have virtually no effect on the diffusion of C.

        SNIGUROVSKA, Y. O.  See abs. 3758.