Estimation of planar anisotropy of the r- Value in ferritic stainless steel sheets

Abstract

Planar anisotropics of γ-values are calculated from crystallite orientation distribution functions (ODFs) by using the Taylor theory. These values are compared with experimentally obtained values for two kinds of ferritic stainless steel sheets with different planar anisotropics of the rvalues and different texture gradients in the thickness direction. Moreover, the most suitable model for predicting the r-value of ferritic stainless steel sheets is examined. For a material with a remarkable texture gradient in the thickness, the ODF in a particular plane perpendicular to the normal direction was unsuitable for predicting the planar anisotropy of the r-value. On the other hand, r-value calculated using the average ODF through sheet thickness measured in a section perpendicular to the transverse direction shows good agreement with the experimentally obtained. The relaxed-constraints model, in which the shear strain components e13 and e23 are relaxed with a CRSS ratio of 1.1 in the {211}(111) and {110}(111) slip systems is the most suitable model for predicting the planar anisotropy of the r-value in ferritic stainless steel sheets. ©2009 The Japan Institute of Metals.