Effect of simple shear deformation prior to cold rolling on texture and ridging of 16% Cr ferritic stainless steel sheets

Abstract

The effect of simple shear deformation by equal-channel angular pressing (ECAP) for one pass on the texture and ridging of ferritic stainless steel sheets with 16mass% chromium has been investigated. Hot rolled and annealed sheets of 4 mm thickness were ECA-pressed for one pass, prior to cold rolling and final annealing. It was found that grains were subdivided by grain-scale heterogeneous plastic deformation, namely, deformation bands, during simple shear by ECAP. Deformation bands appear to contribute to the fragmenting layered structure after cold rolling and facilitate recrystallization of the so-called colonies having {hk/}〈110〉 texture, which are otherwise difficult to recrystallize in final annealing. In other words, strain energy can be stored more effectively by combining simple shear and cold rolling than by cold rolling alone. Recrystallization occurred at a much lower temperature in the process including ECAP than in a conventional cold-rolling only process, replacing colonized {hk/}〈110〉 grains with more favorable {111}〈hk/〉 grains, thus enhancing its formability and reducing ridging. © 2010 ISIJ.