Deformation Mechanism of [001] Oriented Fe-30%Cr Alloy Single Crystals

Abstract

To analyze the rate-controlling mechanism of Lüders deformation found in the [001] oriented Fe-30%Cr alloy single crystals, the activation volume and the activation enthalpy were obtained by a strain-rate and temperature change method during the deformation from 293K to 511K and were found to be 94-176b³ and 0.8-1.4eV, respectively. Aging at 473K was made after extension by 23.5%. The Lüders band didn't move on further straining and the second Lüders band started from opposite side of the chuck. It was considered that the Lüders front was aged and locked by some solute atoms. The line intensity of carbon atom fairly increased around the Lüders front after aging. The interaction of moving dislocations and carbon atom is considered to be the most likely rate-controlling mechanism for the deformation. The activation distance was calculated to be 4.1-6.2 times larger than carbon diameter and would be reasonable value considering the moving dislocations overcome carbon atoms.