A review of research on MnS inclusions in high-quality steel

MnS which has good plasticity is a non-metallic inclusion commonly found in steel. For most steel types, the size, shape, and distribution of MnS have a significant influence on the properties of steel. The large-sized MnS inclusions disrupt the continuity of the steel and cause the anisotropy in steel. The result is a decline of steel's overall performance. In contrast, the small-sized MnS inclusions which in the shape of spherical or spindle in steel can diminish the incidence of thermal embrittlement and improve the machinability of steel. The morphology of MnS in steel is mainly affected by the ingredients of steel and heat treatment manner. MnS inclusions in steel are present in spherical, polyhedral, dendritic, and irregular shapes. The precipitation behavior is mainly affected by the steel ingredients, heat treatment system, and other factors. This paper summarizes the latest research results about the factors affecting MnS inclusions and controlling measures in high-quality steel in recent years.