Distribution of Macroinclusions across Slab Thickness

It can be seen that quite large entrapments (size range 1.0-2.0 mm) were randomly distributed (recorded size distribution for two subsequent surfaces of a typical slab as indicated in Fig. 6 for an illustration) and mostly confined close to the slab surface. Some of those deep seated entrapments are less likely to get removed through scale formation during subsequent soaking of slabs in the reheating furnace prior to hot rolling, and eventually may become potential sources of sliver defects in steel sheets after hot rolling. One way to get rid of them is to scarf the slab up to 4-5 mm depths prior to hot rolling (Fig. 2). © 2012 ISIJ.