INVESTIGATION INTO SEGREGATION OF SELECTED ELEMENTS IN THE BREAKOUT AREA OF A CONTINUOUSLY CAST STEEL SLAB

The paper deals with investigation into segregation behavior of selected elements in longitudinal cut of steel slab, in the breakout area. The breakout occurred after a flying tundish change at a steel grade changing. Altogether 11 samples were taken from the part of a solidified slab. Samples were taken both from the breakout areas and from the areas not affected by the breakout. On these samples concentrations of selected elements (Al, Si, P, S, Cr, Mn, Ni and Mo) were measured using scanning electron microscope and energy dispersive spectroscopy. Concentration data were measured on each sample in 101 points along selected line of 1000 mu m. Concentration data from the individual samples were then subjected to basic statistical analysis. Using the original mathematical models the basic micro-segregation characteristics were further determined for each analyzed element. The parameter of macro-heterogeneity was also determined for individual elements from the measured concentration data. Results - the segregation characteristics - were interpreted with respect to the known technological parameters of casting.