Siemens receives FAC for extended Aluminum hot-strip mill at Novelis in Korea

In February, Siemens received the final acceptance certificate for the extension of an aluminum hot strip mill of Novelis Korea Ltd. in Ulsan. The first coil had been rolled in the third quarter of 2013 within two years from the date of contract effectiveness. The existing twin-coiling hot-reversing mill line, built by Siemens in 1993 was expanded to include a light gauge shear and three-stand hot-finishing mill. The objective of the expansion project was to more than double production capacity, achieve lower end thicknesses and further improve overall product quality, to meet the increasing demand for high-quality aluminum automotive sheet.

The aluminum hot rolling mill, located in the Korean city of Ulsan is able to roll strip up to 2,200 millimeters wide with a thickness spectrum from 1.8 to 6 millimeters. Siemens supplied the complete integrated mechanical and electrical equipment for the new, three-stand tandem rolling mill including a coiler and a coil handling system. The existing reversing stand now functions as a roughing mill. Lightweight cropping shears were also installed in the entry to the finishing line.

The stands of the finishing line are equipped with hydraulic gauge control, positive and negative work roll bending and work roll cooling. The rolling process can be controlled precisely to achieve the required thickness, profile and temperature tolerances. A system for multiple-channel thickness and profile measurement is installed at the exit side of the finishing mill. Strip temperature is monitored with the aid of pyrometers in the finishing line's entry and exit.

The complete automation and drive technology for the hot rolling mill is also from Siemens. The automation technology includes the basic automation plus the technological controls, level 2 systems, the operator control and monitoring facilities, and the associated sensors. One essential element is the process automation with integrated profile and flatness control, which calculates the rolling mill's setpoints online on the basis of analytical mathematical models. The drive systems are entirely AC-based and comprise the main, roller table and auxiliary motors. Siemens synchronous non-salient machines are used for the main motors of stands and coiler. Sinamics S150 medium-voltage converters and Sinamics S120 low-voltage converters are used for the drive system.

All systems and components used are part of the integrated Siroll ALU solution platform for aluminum hot rolling mills. Their modular structure and high degree of standardization warrant a fast production start-up and safe and maintenance-friendly operation. Siemens was also responsible for monitoring installation, commissioning, and customer training.

Novelis Korea Ltd. is a subsidiary of Novelis Inc., Atlanta, Georgia, USA, a leading producer of aluminum and aluminum products. Novelis Inc. operates around 30 production facilities worldwide. The company is the global leader for rolled aluminum products and in recycling aluminum.