A FIXED QUANTITY FOR ALUMINIUM ROLLING MILLS

A FIXED QUANTITY FOR ALUMINIUM ROLLING MILLS For several years, SMS Siemag has been among the world's leading suppliers of rolling mills for flat products made of steel and NF metals.

The range of applications for carbon steels and for high-alloy and stainless quality and special steel grades has always been the dominant field within the company, simply in view of the size of this market. With the strong growth of the worldwide market for aluminium flat products, the share of aluminium rolling mills in the sales volume of SMS Siemag has also risen.

This gave the company reason to grant a larger degree of independence to its own Aluminium sector. Therefore, from the previous sales department that focussed on aluminium rolling mills, an independent "Aluminium Division" has now come into being, embracing not only the sales activities but also the order handling and designing of aluminium rolling mills. This reorganisation enables SMS Siemag to target the aluminium industry and attend to its needs in a much more focussed manner.

The core products of the new division are hot and cold mills for aluminium strips, sheets and plates. Above all

for new plants, the services offered

by SMS Siemag comprise much more than just the rolling mill. The new Aluminium Division nurtures a close cooperation with those other divisions of the company which include aluminium plants in their product portfolio. Such divisions are the Strip Processing Lines and Thermal Process Engineering Divisions which feature in their product ranges a very wide variety of processing lines for the prefabrication and treatment of semifinished products. Such lines comprise not only coating and shearing lines but also all thermal processing facilities such as continuous strip annealing lines and heat-treatment facilities for plates.

The company is therefore predestined for the execution of orders for integrated plants in which the chief concern of the investors is to achieve certain final products in a guaranteed quality and quantity.

Through the large number of facilities supplied, the company has acquired a wide degree of expertise in handling aluminium as a material.

A good example of this would be the equipping of millstands with components that enable processing in a manner compatible with the materials used. Furthermore, SMS

Aluminium hot rolling mill

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Siemag has comprehensive process know-how which, for example, can be integrated into the automation of plants.

The prime equipment in millstands are the facilities for improving thickness tolerances, profile and flatness of the rolled products.

SMS Siemag accordingly equips its millstands with various technology packages which can be combined with one another and thereby achieve the optimisation of the strip geometry both by altering the roll shape and by dynamically adjusting the roll gap.

An essential feature of both hot and cold rolling mills from SMS Siemag is their equipping with the CVC® plus (Continuously Variable Crown) technology. For the rolling of aluminium, CVC® plus is utilized in the hot rolling mill both for improving the strip profile and, particularly with thinner strip gauges, for improving the flatness. In cold rolling mills, CVC® plus is used for producing high-grade final products.

The PFC profile and flatness control system is a dynamic process model that was developed specially for operation in hot rolling mills. In combination with the CVC® plus system and a work-roll bending system, the PFC process model satisfies the most stringent demands relating to the profile and flatness of the rolled strips. On the basis of the pass schedule calculation and the conditions currently applying in the rolling mill, this dynamic process model determines the setting values for the CVC® plus roll shifting, the roll bending and the multizone cooling.

6-high millstands SMS Siemag can claim that it has further developed the 6-high millstand, originally designed for the cold-rolling of high-strength steel strips, into a standard product for the production of high-grade aluminium strips. At all events, the company has supplied, or is in the

Aluminium cold rolling mill

process of installing, 15 six-high stands to the aluminium industry over the past few years, above all in China.

The advantage of 6-high stands is that they cater for a very wide product range, from the hardest of alloys to soft input stock for foil manufacture, as well as for a wide spectrum of strip widths involving width-to-thickness ratios that can be quite extreme.

The higher flexibility of the six-high stand in relation to the fluctuating strip dimensions shows itself to be especially valuable with regard to the strip widths extending from 1,000 to over 2,000 mm that are rolled on a mill. Also for the strip gauges, in which hot strip is reduced from 7 or 8 mm to thicknesses as small as 0.1 mm, the six-high stand has proved itself to be the more beneficial solution as regards the ability to react flexibly to market demands.

SMS Siemag – An established quantity on the Chinese market.

The benefits of SMS Siemag's rolling mills were also quickly recognized by the rapidly developing Chinese aluminium industry. In the period before 2000, the company had already made sporadic deliveries of individual millstands to China, mainly as replacements for older plants.

However, the real break-through on the Chinese aluminium market began with the delivery of two singlestand cold rolling mills to Nanshan Aluminium in 2007. Right from the start, these facilities enabled Nanshan to become one of the most up-to-date aluminium rolling mills in China for the manufacture of can

stock and pre-rolled strip for foilmaking.

Production commenced rapidly and already after a few years a further expansion was called for, resulting in a capacity increase in several steps from the original 300,000 tpa to today's 750,000 tpa. This is being achieved in 2012, for instance, with the commissioning of a threestand CVC tandem cold mill. On the new mill, pre-rolled can-stock strip is rolled in a maximum width of 2,100 mm and gauges of 0.2 to 0.3 mm from hot strip in gauges of 2.4 to 3.5 mm, in a single pass and therefore highly economically.

The two 6-high cold-rolling stands supplied by SMS Siemag to Nanshan in the first expansion stage set the technological standards for virtually all further investments in cold rolling mills for the Chinese aluminium industry. The company has thus delivered 15 more 6-high cold rolling mills in the following years, 14 of them to China to firms such as Chinalco Ruimin, Wanji, Chinalco Nela, and shortly also to Alnan and Shandong Weiqiao, to mention just a few.

During the last two years, SMS Siemag has received further important rolling mill orders from China. These include the hot and cold rolling mill with a capacity of 200,000 tons for Xiamen Xiashun. This mill, which originally gained an excellent reputation as a manufacturer of top quality aluminium foils, has received the following from SMS for its further expansion: a "1+1" hot

mill and a single-stand cold mill for the production of 2,150 mmwide aluminium strips, which can be processed both in the form of pre-rolled foil-making strip and of lithography strip.

It is not only among the country's large, well-established aluminium works that the rolling technology of SMS Siemag has been successfully introduced. Newcomers such as Qinghai PingAn Aluminium, Yunnan Aluminium, Shanghai Datun and Luoyang Wanji Aluminium have altogether ordered, or already received, six six-high CVC cold rolling stands as well as a 1+3 hot rolling mill from SMS Siemag. These facilities are being used without exception for the production of aluminium strip in high quality and in widths greater than two metres.

Among the already existing works, Northeast Light Alloy Co. Ltd. in Harbin, which belongs to the Chinalco Group, has recognized the trend towards the establishment of a Chinese aeronautical industry and has modernized its existing platemanufacturing facilities. Thus, in 2006, SMS Siemag first received an order to build a reversing hotrolling mill for aluminium plates with maximum widths up to 3,700 mm. Plates and sheets down to a minimum thickness of 8 mm are to be rolled from the ingots, of thickness up to 600 mm.

A completely new works, designed exclusively for the demands of the aeronautical and vehicle-building industries, is currently being erected in Nanning in Guangxi province.

Alnan Aluminium Co. Ltd., which has gained previous experience with aluminium in the fields of foil manufacture and extrusion-presses, is moving into the production of plates and strips for the aeronautical and automotive industries and for shipbuilding and, for by far the most part, is making use of Western technologies for its entire production sequence. The company has accordingly ordered both the hot and the cold rolling mills from SMS Siemag. The hot rolling mill comprises a 65-MN reversing roughing stand and a 55MN reversing finishing stand with CVCÂŽ plus technology. Aluminium plates in a width of up to 3,800 mm and a thickness of 8.0 to 260 mm are

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produced. In addition, strips, sheets and plates of width up to 2,600 mm and in the thickness range from 2.2 to 12.0 mm are cold-rolled. The cold mill is a single-stand CVC速 plus cold rolling stand in six-high construction, likewise from SMS Siemag. With a roll force of32 MN and a rolling torque of 476 kNm, the mill satisfies all preconditions for the processing of both thinner and also thicker and harder aluminium strips. The coldrolled strips, covering a wide range of alloys, are up to 2,650 mm wide and thus suitable for the needs of motor-car construction and also, for example, of truck bodies The technology package being supplied by SMS Siemag to Alnan also includes the complete electrical and automation package, i.e. the drive engineering, instrumentation and outfitting with measuring devices, the Level 1 process control and the Level 2 technological models.

The world's strongest hot rolling stand A special challenge was presented by not only the construction but also the delivery and installation of a hotrolling millstand to Aleris in Koblenz.

With its millstand parameters, it can be described as one of the world's strongest hot rolling mills for aluminium plates. Even though it is not the world's largest in respect of the plate width, it is without doubt the strongest hot plate mill as regards the thickness of the rolling ingots, the roll force and the transmittable torque.

The roll gap allows the rolling of 800 mm thick ingots. Also the enlargement of the rolling width from the previous 3,600 mm to the future 3,900 mm provides benefits for the manufacture of wider and thicker aluminium plates for the aeronautical industry, with a view to successfully producing monolithic structures for the reduction of welded joints and for weightsaving.

Really new dimensions, however, are achieved by the new millstand through the roll force of 60 MN

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in combination with the drive power of 2 x 7,000 kW as well as the transmittable torque of 2 x 5,000 kNm with utilization of the permissible overload factors. This equipment enables the stand to satisfy the main demand that has been made, i.e. to achieve a "more thorough kneading" during rolling as a precondition for improving the metallurgical properties. In this connection, Aleris envisages concrete possibilities for supplying the market with new products in the future, involving both monolithic plates and "multiclad" strips for heat exchangers.

The future will be: Plug & Work and Virtual Reality As the outcome of a perfected standardization of the rolling mill components, it is proudly pointed out at SMS Siemag that these components will never depart from the digital path from their initial design to their completion. Even during the manufacturing process the parts remain traceable and are interlinked with the pertaining components.

The consistent implementation of standardization was also one of the preconditions for developing a new process which, in its type and scope in the form practised today as "Plug and Work" at SMS, continues to be unique the world over. The benefits for the rolling mill owners are primarily that all control desks, control cabinets and computing systems are erected and interlinked at the SMS Siemag headquarters before being supplied to the customer. The owners of future rolling mills value above all the possibility of getting to know with their future plant already before it is delivered and also during its erection and installation via simulated real-time operation and becoming familiar with its operation.

Thus, for example, all procedures, extending as far as the complete production process, can be simulated as a real process in combination with the future operation of the

rolling mill already in advance of the mill's delivery, erection and commissioning.

Since the system also includes the preparation of the operating manual, the operator is more or less practically integrated into the preparation and optimisation of "his" own manual. In doing this, he sits at the control desk which he will see again later on in the mill and runs through the various process steps, for which he receives immediate feedback. Plug and Work thus enables not only the training of the future operating crew but also the optimization of the sequences under incorporation of the already available experience of the customer himself.

"Making use of standardization" not only means the storage of unified components in a database but also their storage within the framework of experience-based documentation obtained from the entire handling chain of an order and then making them available to all participants in a new project. With this objective in mind, SMS Siemag has successfully started to develop a new model, designated in-house as a "mock-up".

Under the scope of this model, all departments in the firm that are involved in a project, in other words the sales, design, electrical and automation, research and development and production departments, and also the fitters and commissioning personnel, are all unified in a network, enabling them to depict the new project as "Virtual Reality" and discuss all details of it on this platform. The aim is to find an overall solution that is optimized in respect of tasks and customers and incorporates all of the experience collated in the different locations and departments of the firm. All participants involve themselves simultaneously in the project and make a joint definition of the optimum standard in each instance.

Trust...

Solid competence for the aluminum industry Being able to trust in the expertise and performance of every team member, is the foundation for success. To our customers around the world this means being able to count on a comprehensive offering in the area of aluminum production. From thermal pre-treatment to shaping and refining, we always meet the constantly rising challenges of the market.

Whether in new plant construction or revamp projects, our solid process know-how encompasses the complete production cycle, including the integration of the latest electrical engineering and automation solutions.

Confidence through performance – SMS Siemag.

SMS SIEMAG AG

Eduard-Schloemann-Strasse 4 40237 DĂźsseldorf, Germany

Phone: +49 211 881-0 Fax: +49 211 881-4902

E-mail: communications@sms-siemag.com Internet: www.sms-siemag.com

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