Jul 18 2014
The coupled pickling line-tandem cold mill (PLTCM) supplied by Siemens Metals Technologies was commissioned for Valin ArcelorMittal Automotive Steel Co., Ltd. (VAMA) at the end of May. The line is part of a new cold rolling complex in Loudi, in the Chinese Province of Hunan.
The first extension stage will produce 1.5 million metric tons of cold strip per annum, including high-strength steel grades for applications in the automotive industry. The cold rolling mill has been designed with the capability to be expanded at a later stage of time to reach an annual production of two million metric tons.
VAMA is a joint venture of ArcelorMittal and the Chinese companies Valin Iron & Steel Group Co., Ltd. and Hunan Valin Iron & Steel Co., Ltd. The production plant in Loudi will supply the Chinese automotive industry with high-quality sheet metal. Siemens provided all the mechanical and electrical equipment for the coupled tandem pickling line, as well as ancillary equipment, such as the hydraulic and pneumatic systems, and the safety engineering. The PLTCM has a common, all-embracing automation system, comprising basic (level 1) and process automation (level 2), as well as special process models. This enables high availability and output to be achieved while maintaining constantly high product quality. The systems and components used are part of the Siroll CM solution concept specifically developed for cold rolling mills. Siemens also supervised the installation and commissioning of the tandem pickling line.
The tandem line consists of four six-high rolling stands with a rated power of 7,000 kW per stand. The maximum roll separating force is 35,000 kN. This enables extremely high-strength steels to be rolled within tight tolerances. Smart Crown rolls along with special actuators and control systems ensure that the finished products have the required flatness. C-block stands with an integrated roll change system, rod-type, long-stroke cylinders for the hydraulic automatic gauge control (HAGC), a carousel coiler and a trapped looper were used for the first time in a coupled tandem pickling line. The entry thicknesses of the strip ranges from 1.8 to 6 mm, while the exit thicknesses is between 0.5 and 2.5 mm. The line rolls strips with widths ranging from 900 to 1,890 mm. The maximum rolling speed exceeds 1,400 m/min. The line can process many different steel grades, including mild steels, high-strength, low-alloy steels, various IF steels, DP, TRIP and BH (bake-hardening) grades up to the highest strength steels with a tensile strength of 1,200 N/mm².
Further information about solutions for steel works, rolling mills and processing lines can be found at www.siemens.com/metals.
Source: http://www.siemens.com/