Grain boundary in oxide scale has profound influences on the deformation behaviour and tribological properties of metal alloys at high temperature. This chapter introduces some recent progress to quantify microstructure and interface quality, providing examples of possible property variations. Some fundamental issues of oxidation mechanism have been given, consisting of crystal structures of iron oxides and oxidation of steel alloys. Two main things are addressed: One is what the characters of grain boundaries are developed in the oxide scale, which is associated with grain shape and size, microtexture, and special grain boundaries such as coincident site lattice (CSL) boundaries. Another is the role of grain boundaries played during metal processing, including initial oxidation via grain boundary diffusion, stress and deformation processing, and tribological properties of oxide scale at metal processing. Finally, a more extensive effort was also made to summarise the experimental techniques used to investigate oxide scale.
Part of the book: Study of Grain Boundary Character