Whisker growth morphology of high temperature oxides grown on 304 stainless steel

► The oxidation of as-cast 304 stainless steel is related to the surface finish. ► Nodular growth was seen at extended oxidation times. ► Whisker growths occurred on both the surface and on nodules. ► Whisker formation may be linked to microstructural features. During the high temperature oxidation of as-cast Type 304 stainless steel there is a complex growth pattern of the oxide layers which is shown to be dependent on; alloy composition and local segregation, surface finish, temperature and atmosphere. Of interest is the appearance of whisker growth morphologies which grow in excess of 10 μm in length and at random orientations to the sample surface. This paper illustrates these features and discusses the formation mechanism in terms of the oxide microstructure.