Analysis of Steel Cleanness via SEM Image/Compositional Analyses

Steel cleaness is extremely important to the performance characteristics of  any mechanical systems component. It is a foundation upon which outstanding performance can be built. Excellent steel , together with proper design, heat treatment and finishing techniques/factors creates a winning combination for the end user. Dedicated SEM image/compositional systems are now available and can be employed to provide detailed quantitative information on the non-metallic inclusions populations found in steels produced  by various steelmaking practices ( e.g.  air melt, ESR and VAR). A study was conducted using a set of mid-radius samples prepared from 210 mm diameter bars. Values from a series of cleanliness metrics, including SEV, are reported and compared. Explanations are proposed for changes observed in the distributions and compositions of different types of inclusions. The capabilities of these new analytical tools can greatly assist not only the steelmaker but also the component designers and processors in the achievement of optimal properties in a final part.