Abstract
Concentration profiles through duplex scales formed on vacuum annealed 316 stainless steel have been investigated using neutron activation analysis and energy dispersive analysis. Good qualitative agreement between the two analytical techniques was obtained for chromium concentration profiles in the outer oxide. These indicated a low rate of chromium diffusion into the Fe3O4 layer. There was less agreement between the two methods in the inner oxide as the neutron activation results were complicated by the presence of metal in sections through this oxide layer. The energy dispersive results in this layer were consistent with previous findings which indicated conservative or non selective oxidation occurring.