Zero Inclusion Steel and its Oxide Inclusions Characteristics

Vacuum induction melting and electron beam melting have been used to produce a steel with a composition of 4x10 - 6 T[O], 5x10 - 6 [S], 3x10 - 6 [N]. Examining the samples of the steel with original position analysis and SEM showed that the non-metallic inclusions in the steel were mainly alumina particles with a size ranging from 1 to 4 microns. The morphology and composition of the inclusions extracted electrolytically from the steel were analysed using SEM and EDS. It was found that some deoxidization products and lining materials with a size ranging from 10 to 20 microns, and some flux inclusions with a size around 40 microns existed in the steel. Most of these bigger inclusions originated from raw materials. Finally this paper also proposed an effective method to remove these bigger inclusion particles from zero inclusion steel.