Quality strip is about metallurgical precision – high strength and toughness at alloying levels that keep costs down and preserve weldability. It is also about precise thickness across the full width, as well as consistent flatness to assure fit-up in fabrication. For the successful coil producer, the mill is more than the rolling stand(s) at its core. Ancillary processes, in cooling and levelling in particular, are vital to quality, and the control of a distributed process is the key to efficient asset utilization. Beyond the operations and the engineering, there is a business – one that supplies some of the most safety-critical applications, and the most demanding customers in all of industry. When you are looking for a reliable and expert partner for your venture in this market place, Primetals Technologies is this partner.
Designing a steckel mill is far more than an exercise in mechanical engineering – it is a special and unique example of combining operational efficiency and metallurgical function. Steckel-plate and coil products derive their properties from the combination of the deformation and temperature path they follow, and this means that flexibility to roll a broad mix in a single mill is built into the layout and the mill parameters. These design factors have to be right for all time. Getting them right starts with a complete understanding of process metallurgy, and translating this into a complete and robust design relies on experience. Primetals Technologies has more experience than anyone of the design and supply of modern wide plate mills, allowing us to develop and use engineering tools specifically for the Steckel mill.
Tools for Successful Design
- Bespoke Process Models (incorporating metallurgy as well as roll-bite mechanics and heat transfer)
- Facilities Design Methods (leading to maximized asset utilization under optimal deformation-temperature paths)
- Finite Element Analysis and Simulation (modern engineering tools to prove and optimize equipment performance)
Fig.1- The steckel mill is a reversing mill with a heated coiler at each end | Fig.2- The steckel mill is suitable for lower tonnages
A twin stand mill with a rougher stand before the steckel mill is suitable for an output of 800,000 tonnes a year.
- Mill types: 4-high work roll shift mill; 4-high Pair Cross mill (PC mill) with on-line roll profiler and dynamic PC option for dynamic Automatic Profile and Flatness Control (APFC).
- High-speed threading: 2m/sec or higher to maintain top and tail temperatures
- Short gap time: Time between passes less than 3 seconds except first two passes
Stable rolling: Hydraulic servo side-guide and appropriate furnace coiling tension
- Quality control: Head & tail thickness compensation, AGC, APFC, AWC, CTC, QOC (Quick Open Control)
The best designed and installed steckel mills guarantee a long operating life, through changing markets as well as emerging and improving technology. The key to a sustainable asset is modular technology, allowing upgrades to be made as efficiently as possible in both time and cost terms. The integration skills of Primetals Technologies and our broad base of engineering disciplines, from machine design through process control and metrology, make us an ideal partner in the maintenance and development of the steckel mill as a lasting asset. The potential of the modular approach is wide-ranging too. It can equip a new operator for a low-volume market at entry with scope for future capacity growth, or it can guide an established operator into new product markets. Future-proofing of a customer's business may be the greatest challenge for any technology provider, but in steckel mills, Primetals Technologies is your partner to provide it.
Examples of Modular Technology
- Profile and Flatness Control
- Transformation Monitor
- Shear Technologies
- Steckel Coiler Furnace
- Coiler Technologies
- Addition of rougher stand before mill
- Addition of two or three stand finishing mill
- Plate transfer device
Reproducible quality and efficient use of charging materials – thanks to integrated process models today's demands for flexible and economic production of steel plate can only be met by electrical and automation solutions based on technological process modeling, high-performance control systems, and a comprehensive understanding of hot rolling technology. Steel strips and plates produced in plants supplied by Primetals Technologies is used in a wide range of infrastructural and industrial applications, including pipelines, offshore platforms, wind farms and shipbuilding. Primetals Technologies Plate Mill Portfolio PM has everything to bring your plate mill up to speed, including powerful mill drives for higher throughput, a sophisticated automation for relieve of operators from manual input and integrated online process models to help ensure reliable, reproducible quality, and enable you to produce plate more accurately than ever before. Our complete plant solutions accommodate both forward and reverse processes, providing the basis for optimal resource use, minimized waiting times and reduced maintenance and spare parts costs.
With tailor-made modernization packages, operating mills can be brought to a state-of-the-art level, applying the latest technology and extending the production range to today's requirements.
Electrical and automation solutions meet new and challenging requirements. AC motors and drives – the most powerful available – have established themselves as an economical, versatile solution in plate mills. With low maintenance and great efficiency these drives are in particular fitted for peak overload and reversing operation. The Primetals Technologies Plate Mill automation solution allows the mill operator to utilize a wide range of rolling schedules, such as temperature controlled rolling in dynamic batches, rolling of tapered (thickness profiled over length) plates, and plant view control in fully automatic operation.
Automation Solutions - Complete process control at all levels
In order to master production processes, we must first fully understand and map them in physical-metallurgical models. Thanks to ongoing cooperation with our customers and collaboration with universities and metallurgical research institutions, we now have detailed models for the entire rolling process. These provide a solid basis for our leading automation solutions, especially in the area of heavy-plate technology.
Automation Platform - The leader in industrial automation.
With its standardized components and modular structure, the process control system is the fully scalable backbone, while accommodating the full range of specific rolling mill requirements. Features include unified functional blocks in the software landscape to minimize familiarization and maintenance time, integrated system information data for efficient maintenance and quality assurance, an integrated production monitoring system that is fully scalable for all production processes, and optimum support of operating personnel with an easy-to-understand human-machine interface.
Process meets Project
We offer our customers three propositions that guide our business.
- Process know-how underpins plant design, because this is what assures both metallurgical quality and operational efficiency.
- Translating the concept into a working asset demands co-operation, so that customer and supplier share common goals. Through our excellent project management and collaborative approach, we ensure an early return on investment for all partners.
- A sustainable steckel mill is one that can be adapted and developed over time, quickly and at a competitive cost. Modular technology is the key, and so our principal Research & Development effort is directed at packages that can enhance an existing mill, responding to specific and evolving market needs.
Fig.3- Steckel mills can be used to roll wide plate as well as strip
Once the design concept is known and agreed, realizing it becomes a collaborative process. At Primetals Technologies, project management is just as much a core skill as our engineering, and our long track record teaches us that the most successful projects are also the most co-operative ones. When customer and supplier understand and respect each other's investment in the project, co-operation can follow. A single common plan to manufacture, install and commission the new equipment leads to the quickest and most secure return for both partners, and builds the right relationship to keep on working together throughout the life of the plant. This philosophy holds true regardless of the capital scale of the project, whether it is an entire new mill or a single item of line equipment.
- Commissioning Philosophy
- Lifetime Services
- Approaches to Finance