WORK-HARDENING AND RECOVERY RATES IN A Fe-3. 5 atMo ALLOY DURING HOT DEFORMATION.

In order to clarify the high-temperature deformation mechanism in solution-hardened iron alloys, the work-hardening rate without dynamic restoring effect, h, and the softening rate without work-hardening effect, r, were measured by the stress-change test during creep of an Fe-3. 5at%Mo alloy in a temperature range 1,063-1,138 K and a stress range 5. 4-18. 8 MPa. It was found that the measured effective-stress for dragging the solute atmosphere around dislocations agreed well with that derived from the Cottrell-Jaswon theory and the measured internal-stress was described by the attractive-junction theory. From the changing rate of internal stress after the stress change, h and r were determined as a function of the internal stress and temperature. The parameters h and r are shown to be useful for the prediction of mechanical behavior along an arbitrary deformation path.