Aug 6 2010
A slab caster capable of casting slabs in thicknesses up to 400 mm was recently started up at the steelworks of the Qinhuangdao Shouqin Metal Material Co., Ltd. (Qinhuangdao Shouqin), located in Qinhuangdao City, Hebei Province.
The caster is equipped with a wide range of advanced technological packages to enable the production of sophisticated steel grades for high-end downstream product applications.
Torchcutting of the first slab cast on the jumbo caster of Qinhuangdao Shouqin, China.
In June 2008, Siemens VAI received an order from Qinhuangdao Shouqin for the engineering and supply of key equipment for an ultra-thick, straight-mold, vertical-bending-type slab caster capable of casting up to 1.1 million tons of steel per year. The caster was designed with a bow radius of 11 m and a metallurgical length of 45 meters. Slabs can be cast in thicknesses between 250 mm and 400 mm and in widths from 1,600 mm to 2,400 mm. The product mix includes low- to high-carbon, peritectic, structural and HSLA (high-strength, low-alloy) grades for the production of pipes and plates for use in, for example, the shipbuilding and petroleum industries.
Liquid-core unbending of all strand thicknesses, including 400 mm formats, is performed to enable high slab quality at an increased caster output to be achieved in comparison with solid-core unbending of the strand. This is made possible by the extremely robust design of the caster in combination with a wide range of advanced systems and technological packages. These include solutions for automatic mold-level control, strand break-out prediction, dynamic and on-line mold-width change as well as flexible and on-line setting of the mold-oscillation parameters in the caster head area. Smart Segments in the strand-guidance system make the quick and fully automatic online adjustment of the strand thickness possible.
The Dynacs 3D secondary cooling model is being applied for the first time in Asia. This enables the temperature at any point within the entire strand to be accurately calculated in real time and in a full three-dimensional mode. On the basis of this information, the optimum secondary-cooling setpoints as well as the point of final strand solidification are defined. The roller-gap taper in the area of final strand solidification can then be dynamically and precisely adjusted by applying DynaGap Soft Reduction technology. This minimizes strand segregation as required by high-quality plate applications. Dynamically adjustable spray nozzles are used to avoid overcooling of the slab corners for all slab widths.
All casting equipment and systems functioned as designed from the first heat. Excellent teamwork between customer and supplier personnel in combination with the installed Connect & Cast solutions were decisive factors for the on-time and smooth start-up of this slab caster at Qinhuangdao Shouqin.