| SMS Meer GmbH, Germany, has received an order from Trinecke Zelez�rny a.s., Czech Republic, for the modernisation of a two-strand merchant bar mill. The modernisation project is being implemented in two construction stages and, as far as absolutely possible, the plant will continue in productive operation with only short idle periods. The commissioning of the first construction stage, that includes walking-beam furnace and roughing mill, will take place in 2003, as well as the preparation for the second construction stage. The new ASC� mill stands (Automatic Size Control) will be installed and operational within just one week at the beginning of 2004.
The purpose of the revamping work is to increase the share of high-grade steel production (SBQ) bars, to enlarge the product dimensions and to manufacture merchant bars with a finished tolerance of 1/4 DIN. The new pass design and the quick-changing facility at the finishing stands will assure a high-degree of flexibility in the future for the rolling mill, with short idle periods and roll-change downtimes. The rolling mill will be operated as a single-strand facility for high-grade steel, which will include cold-heading, anti-friction bearing, spring, free-machining and stainless steel grades. The dimensional range comprises round steel from 16 to 70mm, square steel from 14 to 50mm, hexagon steel from 17 to 50mm and flat sizes from 25 to 90mm widths. Concrete-reinforcing bars (10-40mm) and angle bars (30-50mm) will continue to be produced by the two-strand method.
The supply scope of SMS Meer comprises the new walking-beam furnace with a capacity of 160 tonnes per hour, replacing the two existing pusher-type furnaces. In addition, the German company will install a new four-stand roughing train in H/V arrangement that will bring an enlargement of the initial section from 108mm to 150mm2 and, in the future, to 160mm2. In addition, adaptations will be made to the drives of the existing stands of the intermediate train and finishing mill and their equipment. Furthermore, a new pass design for the roughing, intermediate and finishing stand groups will make it possible to manufacture high-grade steel bar stock. The core elements of the modernised rolling mill will be the two new finishing stands featuring ASC� technology, which will guarantee finished tolerances of 1/4 DIN over the full length of the bar. The ASC� system, developed by SMS Meer, comprises the interplay between diameter-measuring devices and innovatory two-high stands. These are equipped with a rapid, hydraulically operated roll-gap setting system. The two prime advantages of these ASC� mill stands with hydraulic roll-gap setting are the optimum pre-setting of the roll gap upon changing the rolling programme and the ability to compensate the varying lateral-spread and shrinkage behaviour of different steel grades. These features guarantee reproducible rolling conditions, independently of the operating personnel. The very first bar of a new rolling lot is produced within the desired tolerance, and it is not necessary to have expensive test bars for running-in of the rolling mill. The modern cassette-type design of the ASC� mill stands enables the programme to be changed in a mere five minutes.
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