Gerdau Açominas, a company in the Gerdau Group, has ordered a plate mill and a Steckel mill from Siemens VAI Metals Technologies. The two rolling mills will be constructed at Ouro Branco in the state of Minas Gerais, Brazil.
A second strand will also be added to their existing Siemens VAI continuous slab caster that initiated its production one year ago. As from the end of 2012, 1.1 million tonnes of heavy plate and over 800,000 tonnes of hot-rolled coil are scheduled to be produced annually. The value of the order exceeds 290 million US dollars.
The two new rolling lines are part of an investment program for the Ouro Branco Steel Works, which is intended to launch Gerdau Group as a flat carbon steel producer in Brazil. The end products include not only high grade plates for API (American Petroleum Institute) linepipes, but also for shipbuilding, the construction industry and pressure vessels. Under the investment program, Siemens VAI has already supplied a single-strand continuous slab caster, with a capacity of 1.5 million tonnes per annum, which was put into operation in May 2009. As part of the current order, a second strand with the same capacity is to be added to this casting machine.
Siemens is supplying all the mechanical, electrical and automation equipment for the two rolling lines. The plate rolling line consists of a single-stand plate rolling mill, a pre-leveler, a Mulpic intensive cooling section and a hot plate leveler. Downstream there are cooling beds, a double side trim shear and a dividing shear, a cold plate leveler and the thick plate cutting area. An ultrasonic testing station is provided for quality assurance. The heavy-plate line will produce plates with thicknesses between 4.5 and 150 millimeters, widths between 900 and 3,600 millimeters, and lengths between 3 and 18 meters.
For the Steckel mill, Siemens is supplying the Steckel rolling stand with coiler furnaces, a crop shear, a laminar flow cooling section, and the downcoiler with its associated coil handling devices. The rolling line is designed producing steel strip ranging in width from 900 to 2,100 millimeters and in thicknesses between 2 and 20 millimeters. The scope of supply is completed by fluids systems and the water treatment plants for the two rolling lines.
The solution for the two rolling lines is based on the integrated Siroll PM concept for plate and Steckel mills. The main drives of both rolling mills are to be equipped with non-salient pole synchronous motors powered by Sinamics SM150 voltage source converters. The scope of supply also covers the complete instrumentation, the measuring system and the automation, and includes all the technological control systems and process models. The Siemens microstructure monitor will also be used in the plate rolling mill, making it possible to determine the mechanical properties of the heavy plate reliably in advance.
Siemens Brasil Ltda is providing the complete power supply, including high, medium and low voltage switchgear, and the electrical equipment for the water treatment. Siemens VAI will also be responsible for supervising the installation and commissioning of the equipment supplied.
The main factors that won the order were the comprehensive technical concept and Siemens’ ability to offer not only the mechanical and electrical engineering but also technology packages from one source. Siemens’ local presence in Brazil also ensures that qualified support will continue to be provided during the operational phase.