Evolution or revolution?—a new era in billet casting

Abstract

The billet industry was born in the mid-1960s as a series of scrap recycling plants, at a time when environmental awareness was not even in vogue. Out of the determination and vision of the individuals who forged this industry, a new philosophy of steelmaking emerged. A philosophy based on low man-hours per tonne, and profit sharing gave birth to the highly profitable minimill concept that has now gripped steel production in the flat-rolled area. The billet industry has evolved from being primary suppliers of reinforcing bar to being competitive in high quality products while retaining the original production philosophy. A quiet revolution is now underway in this industry with casting speeds approaching those of thin slab continuous casting. Mould powder lubrication and other practices common to slab casting, such as controlled feeding of liquid steel from tundish to mould in place of metering nozzles are becoming common place. This paper delineates some of the challenges facing the industry which is in the throes of a revolution. Professor Alexander McLean’s early work on the importance of controlling fluid flow in the tundish and its impact on turbulence in the mould is emerging as being critical to the challenge of producing high quality billets at high casting speeds.