Neutron Diffraction Study on Anisotropy of Strain Age Hardening in Ferritic Steel

Abstract

The work-hardening characteristics of anisotropic tensile deformations and the corresponding residual strain changes of pre-strained ferritic steels without and with aging treatment were investigated by using angle dispersive neutron diffraction and electron backscatter diffraction pattern analysis. The plastic deformation along the pre-strained direction leads to evident work-hardening at the beginning stage, showing discontinuous yielding behavior. Comparably, the plastic deformation perpendicular to the pre-strained direction shows continuously yielding. The tensile and compressive residual strains were found in the ‹200› and ‹110› grains along the pre-strained direction, respectively. It is also found that the difference in various oriented grains after strain aging become more evident along the pre-strained direction but smaller perpendicular to the pre-strained direction, revealing a higher work hardening capability in the former case than in the latter case.