Nucleation of Acicular Ferrite on Sulfide Inclusion in Simulated Strip Casting Process

Refinement of the microstructure by formation of fine acicular ferrite (AF) nucleated on inclusion has been caused wide interesting in weld metallurgy and other metallurgy fields. It is also important to refine the as-cast microstructure during strip casting and thin slab casting process in which the possibility of refining microstructure by rolling decreases. In present paper, the possibility to nucleate AF by sulfide inclusion in steel without special alloy elements in rapid solidification process has been investigated. Oxide inclusion and sulfide inclusion are popular in the sample and only sulfide inclusions are observed effective to assistant AF nucleation. The possible mechanisms of formation of AF in present sample are discussed in detail.