Surface physico-chemistry study of an austenitic stainless steel: Effect of simple cold rolling treatment on surface contamination

The surface physico-chemistry properties of stainless steel and the effects of a cold rolling treatment were investigated. X-ray photoelectron spectroscopy (XPS) analyses were carried out on rolled surfaces at different rates. Thus, by characterizing passive film chemistry and contamination layer, the modifications due to this treatment were quantified, in particular an increase of the ratio (Fe/Cr)oxide is evidenced with the level of the cold rolling treatment. Moreover, based on an angle resolved analysis, a new model where the contamination layer is represented as isolated parts was developed in order to describe the geometry of this carbon contamination. XPS experiments show an iron enrichment of the passive film during the cold rolling treatment, which seems to be explained by a surface heating during the mechanical treatment. Therefore, the new island model puts in evidence the effects of ageing time and surface condition on the geometry of carbon contamination. Hence, cold rolling increases the thickness and the recovery of carbon contamination on the stainless steel surface.