2015 年 101 巻 11 号 p. 619-625
Equal-channel angular pressing (ECAP) was applied to ferritic stainless steel sheets for one pass prior to cold rolling in order to improve formability and alleviate ridging of the sheets. Effect of the channel angle of ECAP (90° and 120°) on the deformation microstructure and the subsequent recrystallization was focused. One-pass ECAP indeed modified the cold-rolled microstructures, texture and subsequent recrystallization as compared with that in cold rolling alone. In particular, grain-scale shear bands are introduced during ECAP in otherwise hard-to-recrystallize <100>//ND grains by ECAP, and they facilitated the recrystallization. However, the effect of reducing the channel angle from 120°to 90°on the recrystallization and the formability was limited in spite of higher shear strain imposed on the sheets. The reduction of the channel angle affects an increase of misorientation between the shear band and the matrix and does not increase the density of shear band.
