9th ECCC European Continuous Casting Conference – ECCC 2017

Non Metallic Inclusions in the slab may cause clean steel defects such as slivers, blow holes and laminations. The main inclusions found in these defects are mould slag particles, argon bubbles accompanied by alumina or sometimes by slag particles and calcium aluminates. In some occasions clogging products are found. When doing root cause analysis to the origin of these clean steel defects it is difficult to assess where the precursor of the defect got entrapped in the slab. To complicate matters it is found that inclusions already present on the slab surface may be precursors of clean steel defects as well. Knowledge of entrapment location is essential to be able to improve the casting process. This study shows that most – but not all - defects originate from inclusions in the slab and that the entrapment mechanism is related to the type of clean steel defect. It will be discussed how an EMBr is used to improve fluid flow and mould heat transfer thus reducing the risk for defect formation.