In the field of hot rolling, Siemens VAI Automation systems are available for reheating furnaces, hot-strip mills, plate mills and Steckel mills. Precise and flexible process models incorporating fuzzy logic and neural networks optimize the rolling process from the reheating furnace to the downcoiler exit.

Latest state-of-the-art controller technologies, including non-linear control loop systems and advanced identification methods, ensure fulfillment of strip dimensions within closest tolerance ranges. Higher-level optimization systems promote total scheduling flexibility and increased mill throughput.

Spectrum of Solutions

• Furnace Optimization and Control Model - For energy savings up to 10%
• Rolling Optimization Model -For improved adjustment of process parameters for improved product properties
• Automatic Width Control - For width tolerances +/- 3 mm
• Automatic Crop Optimization - For yield increases up to 0.75%
• Advanced Gauge and Tension Control - For thickness tolerances down to 1/4 of standard values
• Profile and Flatness Optimization and Control Model - For profile variations < 20 µ and flatness deviations within 30 I-Units
• Strip-Cooling-Temperature Control Model - For coiling temperature deviations < 16 °C
• Step Control - For superior surface quality
• Advanced Drive Systems - For high efficiency and exact roll-speed control
• Schedule-Free-Rolling Optimization - For increased scheduling flexibility and longer rolling campaigns with the same work-roll set

Siemens VAI-Q Strip

Siemens VAI-Q Strip is an extraordinary quality-control system for hot-rolling mills which allows the mechanical properties of hot-rolled strip to be predicted and controlled online. The system is based on a detailed physical-metallurgical modeling of the entire rolling process which enables the microstructure of the hot-rolled product to be assessed with a high degree of accuracy. Through an online adjustment of specific process parameters (e.g., finishing and coiling temperatures), the mechanical properties of the hot-rolled strip can be directly controlled. The benefits are obvious - significantly improved strip quality, simultaneously reduced alloying costs and facilitated production of new steel grades through simulation techniques. Siemens VAI-Q Strip has been installed in the 7-stand hotstrip mill, where the system has been in continuous and successful operation since 1997.