The dislocation damping in cold worked α-iron is studied with a torsion pendulum. The component (
QH-1), which is dependent on strain amplitude of the dislocation damping, is proportional to strain amplitude and vanishes at the first stage of recovery (-40_??_-20°C). This recovery seems to be due to a thermally activated rearrangement of unstable dislocations. The component (
QI-1), which is independent of strain amplitude ;and has a weak dependence on temperature, disappears at the second stage of recovery (20_??_40°C) by pinning of dislocations with interstitial impurities (carbon and/or nitrogen). Experimental results seem to be explicable on the basis of a static hysteresis model taking account of thermal unpinning of dislocations from impurities.
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