The surface relief adjacent to persistent slip bands in polycrystalline 316L stainless steel, cycled at constant plastic strain amplitudes of up to 60% of the fatigue life, was studied by using atomic force microscopy. It was found that the surface relief was made up mainly of ribbon-like extrusions whose height in a grain was proportional to the thickness of the corresponding persistent slip band. The extrusions grew predominantly in the direction of the active Burgers vector. The height of an extrusion in the direction of the active Burgers vector was proportional to the grain size. No systematic dependence upon grain orientation of the extrusion height in the active slip direction was observed. The results were explained in terms of recent vacancy models for surface relief evolution.

Atomic Force Microscopy of Surface Relief in Individual Grains of Fatigued 316L Austenitic Stainless Steel. J.Man, K.Obrtlík, C.Blochwitz, J.Polák: Acta Materialia, 2002, 50[15], 3767-80