Oxide scale behaviour and surface roughness under hot rolling conditions of Fe-Ni36 Invar alloy

In this study, hot rolling tests of Fe-Ni36 invar alloy were carried out on a 2-high mill at different temperatures and various reductions. The specimens of the hot rolling tests were designed in the shape of stairs to investigate the relationship between oxide scale, surface roughness and reduction. The surface characteristics and the cross section morphology of the oxide scale were observed under an optical microscope and with Scanning Electron Microscopy (SEM). The chemical compositions of the oxide scales were investigated using Energy Dispersive Spectroscopy (EDS). The thickness of the oxide scale and surface roughness were measured. It was found that with an increase of reduction, the oxide scale thickness and the surface roughness decrease obviously.