Anisotropy of nickel release and corrosion in austenitic stainless steels

The study of 316L-type stainless steel reveals a significant anisotropy of nickel release that is dependent on the orientation of the test surface with respect to the casting and rolling direction. Cross-sectional specimens (transversal cuts with respect to the rolling direction) show a substantially higher sensitivity to corrosion phenomena compared with longitudinal cuts and they release nickel ions at rates 10–100 times higher. These findings indicate that orientation needs to be taken into account when interpreting test results, in particular when comparing different grades of austenitic stainless steel, as well as in product and production design.