Centreline defects in strips produced through thin slab casting and rolling

Abstract

Segregation in conventional slabs has been the topic of multiple researches; the centreline segregation in thin slabs has not been explicitly reported in published literature. However, a centreline band (defect) is invariably observed on macroetching high-manganese (>1 wt-%) strips from thin slab casting and rolling route of TATA Steel, Jamshedpur. A study was conducted to establish the exact nature of centreline defects and correlate with observation in the corresponding slab. Presence of second phases at the centreline due to heavy manganese enrichment was observed to be the source of defect band. In summary, this paper establishes a direct correlation between defects in hot-rolled strips and macrosegregation in thin slabs and highlights countermeasures taken to address the defect.