The role of oxide-scale microtexture on tribological behaviour in the nanoparticle lubrication of hot rolling

Electron backscatter diffraction (EBSD) of the microtexture in the tertiary oxide scale after hot rolling were investigated. The surface asperity flattening and grain refinement of Fe3O4 were produced at a thickness reduction of 28% and a cooling rate of 28 °C/s. Microtexture development of Fe3O4 manifests as a strong θ fibre parallel to oxide growth, including the {100}<001> and {001}<110> textured components, whereas the {0001}<101̅0> component dominates in α-Fe2O3 as the favoured basal slip. The tribological effect of α-Fe2O3 at the contact surface of steel and rolls was considered at low and high thickness reductions. The propagation of cracks along the Fe3O4 grain boundaries could create a dish to collect nanoparticles during lubrication and thereby changed the wear rates.