Suppression of Axial Nonuniformity in Continuous-Cast Steel by Inoculating It with a Clad Powder Inoculant.

This article cites a study investigating the suppression of axial nonuniformity in continuous-cast steel by inoculating it with a clad powder inoculant. A metallographic analysis showed that microcracks up to 10 mm wide and up to 5000 mm long are formed in the region where the steel is structurally and chemically nonuniform. Researchers have attempted to determine the reasons for the formation of the microcracks by studying the fracture surface, which passed through the axial zone. The study was conducted with the use of electron fractography, spectral microanalysis, and micro-diffraction. It was determined that the cracks are formed mainly on inclusions of manganese sulfides and titanium carbonitrides, which occupy a substantial percentage of the fracture surface in the axial zone. Researchers have also devised a method of using the same type of standard specimen to separately determine the mechanical properties for the matrix and the metal in the in the axial segregation zone.