Effect of transients on quality of continuously cast product (TRANSIENT) (SUPSYSCC)
This is a collaborative project between Tata Steel (formerly Corus), Gerdau- Sidenor (formerly Sidenor), VDEh-BFI, Tecnalia (formerly Labein), Riva, SSSA and ArcelorMittal Rurhort. The principal aim of this project has been to improve the understanding of the causes and effects of transient conditions on surface and internal quality during the continuous casting of a range of grades as slabs, blooms and billets. The transient conditions have included casting speed variations, flow rate changes, ladle changes, flying tundish changes, start and end of casts, and grade changes. This has allowed... new practices to be developed to eliminate or reduce the quality problems associated with transient events and new rules for downgrading as-cast material following transient events. Four innovative caster monitoring systems were developed in this project and used to gather process and quality data. Several advanced models were developed using CFD, FEM and finite difference methods, as well as artificial neural networks; these were used to understand more deeply the transient phenomena investigated and to develop countermeasures where possible. Plant trials on five industrial casters covering a variety of formats and grades, led to the identification of nineteen transient phenomena. These were investigated using data analysis, metallurgy and modelling. Where possible, countermeasures were developed, trialled and refined, leading to improvements in operability and substantial improvements in product quality. A guide sheet has been created to assist plants in tackling similar phenomena, and to identify areas for more in-depth research. The exploitation and impact of the results have been discussed.