Electromagnetic stirring for continuous casting - Part I

Electromagnetic stirring (EMS), also called induction stirring, uses rotating or travelling magnetic fields to generate a motion of the liquid steel with the purpose to obtain metallurgical improvements. The present article is limited to continuous casting and to alternating magnetic fields, it thus does neither describe the stirring of liquid steel in the ladle nor the electromagnetic brake using permanent magnetic fields in slab casting. The article is divided into two parts : the present part I offers in a first chapter a historical review of EMS in billet, bloom and slab casters. It then describes the basics of electromagnetism and fluid flow that are relevant for the understanding of EMS. Part II, to be published in June 2003, presents the metallurgical principles and the industrial applications and results.