Centerline segregation - Slab defects

Centerline segregation - Slab defects

Figure 1: Sulfur print showing centerline segregation in a continuously cast steel slab (courtesy of IPSCO Inc.).

Defect name: Centerline segregation
Record No.: 3356
Type of defect (Internal/Surface): Internal
Defect classification: Slab defects
Steel name: Steel
Steel composition in weight %: No data.
Note: Many of the solidification phenomena, structural features, and macrosegregation patterns in continuous casting of steel are similar to ingot casting if one measures time with respect to a reference frame that moves with the strand. Axial segregation and V segregates, although less pronounced, may be seen in longitudinal sections of continuously cast steel. A sulfur print showing a typical centerline segregation pattern in a slab is shown in Fig. 1. Here, an important additional factor influencing the segregation is bulging of the slab owing to inadequate roll containment close to the bottom of the liquid pool. The bulging draws enriched liquid down into the center of the slab where it freezes.
Reference: Not shown in this demonstration version.