The dislocation structures of fatigued austenitic stainless steel polycrystals were analyzed by means of electron channelling contrast imaging. The formation of persistent slip bands and vein structures was recognized in some grains. The effects of both grain size and Schmid factor upon the persistent slip band formation were investigated. The average diameter of the grains containing persistent slip bands was higher than that without persistent slip bands. On the other hand, there was no significant difference in the average Schmid factor between the grains with persistent slip bands and the other grains. Persistent slip band formation was detected even in grains where the Schmid factor was low and the grain diameter was small. It was proposed that the stress concentration coming from piled-up dislocations in a neighboring grain was one of the reasons for persistent slip band formation in such grains.

Electron Channeling Contrast Imaging of Dislocation Structures in Fatigued Austenitic Stainless Steels. Y.Kaneko, K.Fukui, S.Hashimoto: Materials Science and Engineering A, 2005, 400-401, 413-7