H.E.S. Hennigsdorfer Elektrostahlwerke GmbH (H.E.S), a company in the Riva Group, has issued Primetals Technologies with the final acceptance certificate for a modernized, turnkey bar mill in Hennigsdorf, in the German state of Brandenburg. The modernization project included replacing two existing stands in the roughing mill with new Red Ring stands, which do not have housing. This solution requires less space and has greater rigidity to enable consistently narrow product tolerances to be achieved. The new stands also have larger rolls. This increases the stability of the process and allows multi-strand operation. Primetals Technologies had received the order in May 2015, and commissioning took place during a scheduled plant shutdown at the turn of the year 2015/16 with industrial rolling restored on January 2.
H.E.S. is one of three production locations that the Italian Riva Group has in Germany. The plant converts raw scrap metal provided by Riva Stahl GmbH into steel products, which are then marketed by Riva Stahl GmbH. The range of products includes continuously cast billets, reinforcement steel, and bright steel, which is mainly supplied to the automotive industry and its suppliers.
For the modernization of the bar mill, Primetals Technologies supplied two new type RR564 housingless Red Ring roughing stands with a horizontal configuration. The scope of supply also included couplings, drive spindles and spindle supports. The center line of the rolls can be varied between 480 and 730 millimeters. The roll barrels are 850 millimeters long. A new gear box was also installed on one stand. Stand change parts, a motorized device for roll change operation, and the on-board electrical equipment for the stands completed the scope of supply. Primetals Technologies was also responsible for construction and commissioning.
The bar mill processes billets of carbon steel and low alloy grades with a square cross-sectional area of 140 x 140 millimeters, a length of 12 meters, and a weight of 1.8 metric tons. The final products are rebars with diameters of between 10 and 50 millimeters, and rounds with diameters ranging from 14 to 50 millimeters. The plant can also be run in two-slit mode if the finished products have a diameter of 28 millimeters or less.