Germany’s Saarstahl AG has chosen Concast’s Convex Technology© for its new, 6-strand caster that is presently under construction. Concast will supply the technological heart of the primary solidification equipment, including its quick-change cartridge moulds with integrated MEMS (mould electromagnetic stirrers) and the first containment with below-mould SEMS (strand electromagnetic stirrers) for 150x150mm billets and 180x180mm blooms. In addition, a specially developed Convex mould tube geometry will apply mechanical soft reduction to the 150x150mm billets. This new geometry was successfully tested on the existing S4 caster at Saarstahl in 2002. Extensive trials resulted in establishing practices for successful high-speed submerged casting. In less than a year, all high-demand steel grades were tested, a process that included product homologation. New powders had to be developed and tested since throughputs of more than 500 kg/min for billets required new technologies to allow rapid heat diffusion. Saarstahl’s No. S4 caster is the plant’s workhorse, with a monthly production of 75,000 tons.