Original paper(Vol.50 No.11 pp.1223)

Deformation Mechanism of m001n Oriented Fe-30%Cr Alloy Single Crystals

Sei MIURA and Motohiko KOUSHIMA

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 didnft 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.

Key Words:Plastic deformation, Fe-30%Cr single crystal, Lüders band, Strain ageing