Modernization of the secondary cooling system on a curvilinear caster in the converter shop at the severstal' metallurgical combine

The converter shop at Severstal' has successfully used five curvilinear-type continuous slab casters with a combination cooling system for more than 20 years. However an increase in the percentage of crack-sensitive steels being made has tightened requirements on the surface quality and macrostructure of the continuous-cast semifinished product. The shop was faced with the challenge of improving the secondary cooling system so as to reduce the incidence of surface cracks (especially over the small radius of the caster) and improve the macrostructure while minimizing changes to the design of the water-distributing section. Taking a comprehensive approach to developing a new technology for the secondary cooling of steel has made it possible to improve all the parameters of the technology and the structural elements (improve the cooling regime, design new nozzles and manifolds, and modernize the design of the secondary cooling system and the equipment of the water-distributing section). A prototype secondary cooling that is designed for the casting of crack-sensitive steels and employs a water-air mist was developed and has passed commercial trials. The system has proven to be highly reliable in operation and has improved the quality of the surface of slabs.