High productivity and technological developments at Corus DSP thin slab caster

Abstract

The Corus IJmuiden Direct Sheet Plant focuses on production of thin gauged material through a single casting strand and an (semi-) endless rolling process. The caster has a 90 mm thick funnel shaped mould and is equipped with liquid core reduction, allowing a slab thickness of 70 mm. To reach casting speeds up to 5·4 mm min⁻¹, steel is fed into the mould using a specially designed submerged entry nozzle and an adjustable multi-pole electromagnetic braking system is installed. Although still increasing, productivity is now at the design level of 1·3 Mt/year. Average casting speed (including start and stop procedures) is >5·0 m min⁻¹ with sequence lengths up to nine 300 t ladles, representing a maximum planned casting time of 12 h. Significant growth has occurred in the production of (thin gauged) high strength steels. Breakouts have been a constant threat but stabilisation of the casting process has resulted in significant reduction in these events, allowing steady growth to productivity targets. Developments to improve mould fluid flow, mould level control, mould heat transfer and strand lubrication are described.