The aim of the expansion work is to develop new materials that require higher cooling rates and thus helps thyssenkrupp Steel gain a technological edge over competitors. thyssenkrupp Steel Europe now runs its hot strip mill to produce materials that could only previously be made on plate rolling mills, and uses the intensive cooling system with great success for many grades that used to be cooled only in laminar mode. The high cooling rates and precise temperature control allow exact adjustment of the microstructure. Consequently, smaller quantities of alloying elements are needed to produce certain steel products.
Primetals Technologies installed and commissioned the first stage of the Power Cooling system on hot strip mill 2 in December 2010. A total of 16 cooling headers were installed above and another 16 below an eight-meter section of the run-out roller table. In intensive mode, the height-adjustable headers can provide around 6,200 m3 of cooling water per hour at a pressure of about 3 bar. The 2014 extension doubled the maximum water flow rate. A second group of headers was installed directly downstream of the existing intensive cooling section. The resulting Power Cooling system now features a total of 32 headers above and below an 18.5 m section of the run-out roller table. Four booster pumps, each rated at 375 kW, feed the cooling system. They can raise the laminar pressure to a maximum of 3 bar to achieve the full water flow rate. The capacity of the associated water management system was increased to a continuous output of 9,000 m3/h. This means that the first 18.5 m of the cooling section can achieve cooling rates some five times higher than those of the original laminar cooling section. The conversion work was completed on time during a 14-day plant shutdown.
thyssenkrupp Steel Europe AG is the head company in the European carbon steel activities of thyssenkrupp. The company is one of the world's leading producers of high-quality flat steel. Hot strip mill 2 in Duisburg-Beeckerwerth produces 6 million t/a, which is one of the highest output capacities in the world. The company is continually modernizing this plant to produce many types of modern, high-quality steel for use in the automotive industry and for pipe production.
(Source: Primetals Technologies Ltd.)