Chinese Company Orders Stainless Steel Tandem Cold Mill from Siemens
07/18/2013 - Siemens Metals Technologies has received an order from Beihai Chengde Stainless Steel Co., China, to supply a Power X-HI type, five-stand, continuous tandem cold rolling mill and a heavy laser welding for the Beihai plant in Guangxi Province.
The rolling mill will have a capacity of 600,000 tons of cold strip per annum, and will be designed to produce AISI grades series 200 and 300. The order value is in the double-digit million euro range. The new rolling mill is scheduled to be commissioned in the middle of 2014. This is the third order that Siemens has received from China for a Power X-HI rolling mill for stainless steels.
Beihai Chengde is active in nickel mining and the production of narrow stainless steel strip. The company intends to use the new cold rolling mill to start producing wide strip. Total production should reach 1.6 million metric tons of stainless steel per annum as early as 2014, and four million metric tons in the final expansion stage in 2015.
The continuous rolling mill will handle hot-rolled, annealed and pickled stainless steel. It will be able to achieve exit thicknesses from 0.3 mm to 3.0 mm from entry thicknesses of between 1.0 mm and 5.0 mm. The width of the strip will vary between 800 mm and 1,300 mm.
The continuous rolling mill line comprises three main sections, each separated by strip accumulators. The entry section includes double uncoiler station, each equipped with coil storage facilities, coil loading car and overhung mandrel uncoiler together with coil opening, flattening and shearing equipment. The Siemens welding machine is of heavy laser type (LW21H) and includes strip centering and strip cutting facilities as well as diagnostic systems.
The mill section includes five stands of Power X-HI- type with associated high tension bridles and rinsing section to remove emulsion from the strip surface. The rolling speed will be 400 meters per minute. The rolling stands will be designed for a flying roll change, so production will not have to be interrupted to change the work rolls. This will increase productivity and reduce output losses.
The exit section comprises exit bridle, inspection station, rotary shear, scrap and sample cutting, two recoilers, belt wrapper, paper interleaving feeding equipment, spool loading and coil unloading car with associated coil banding and storage. The strip looper between the rolling line and the exit section will decouple the rolling process from the downstream activities, such as strip inspection and trimming. This means that they will no longer be limiting factors on the mill throughput.
The scope of delivery also includes variable-speed Sinamics drives with a total power of 22,000 kilowatts, and the basic (level 1) and process (level 2) automation. A Simatic WinCC-based solution will handle the operator control and monitoring tasks. It also enables distributed supervision, and features easy-to-use diagnostic and alarm functions.
Pictured below: View into a Siemens Power X-HI rolling stand. A five-stand rolling line for producing AISI grades of 200 and 300 series is being constructed for Beihai Chengde, a Chinese stainless-steel producer.
