微量CおよびNを固溶した鉄の振幅依存内部摩擦

抄録

The interaction of carbon and nitrogen atoms with dislocation in iron was studied by measuring the amplitude dependent internal friction. The measurements were carried out on three specimens containing 10 ppm C, 1 ppm C and 5 ppm N, respectively, by the forced transverse vibration method. The binding energies between these interstitial impurities and dislocation were obtained as a result of an analysis based on the theory proposed by Granato and Lücke. The amplitude dependent internal friction is so sensitive to the locking of dislocations by impurities that the binding energies thus determined are considered to be more reliable than those ever reported. The results are summarized in the following:
(1) The binding energies are 0.55 eV for carbon and 0.80 eV for nitrogen, respectively.
(2) If a calculated binding force between a carbon atom and a dislocation (0.1Gb²) is used, the mean pinning lengths obtained from the amplitude dependent internal friction are in good agreement with those estimated from a thermodynamic equation.