Nucor Steel, Alabama, USA, has placed an order with SMS group for the comprehensive modernization and expansion of its Steckel mill at its Tuscaloosa site. 

The centerpiece of the project is the conversion of the existing plant into a highly advanced tandem Steckel mill. To enhance the rolling mill’s ability to produce thin, high-strength products, an additional high-performance mill stand will be installed downstream of the existing stand to create a tandem Steckel mill. Both stands will be employed simultaneously for reversing roughing passes and finishing passes. The tandem arrangement of the stands also allows the use of special work rolls in one stand to manufacture base plates and checker plates.

The existing entry and exit-side Steckel furnaces will be replaced with new furnaces in a state-of-the-art, closed-type design. These advanced furnaces are highly efficient at maintaining the right product temperature and protecting the roller tables against heat radiation. The improved furnace efficiency reduces the system’s natural gas consumption.

Once the revamp has been completed, both mill stands will be equipped with CVC^® plus technology to ensure maximum strip quality. CVC^® is an extremely effective tool for controlling the strip profile and flatness through a combination of bending and axial shifting of the work rolls with a special contour.

A looper arranged between the stands optimizes the strip tension and assists with speed control.

As the systems supplier in charge of the upgrade, SMS group will also handle the modernization of the electrical and automation systems in the Steckel mill, including the main drives, sensors, measuring equipment and instrumentation, as well as the mill’s basic and process automation.

Thanks to the modularized level 1 software architecture, the system responds very quickly to given requirements and guarantees fault-free performance. For example, the stability of the rolling process and strip guidance is improved with the X-Pact^® Centerline Control system from SMS group, which features intelligent cameras and level 1 automation control functions for highly automated strip control. The level 2 process automation includes the technological process models X-Pact^® Pass Schedule Calculation PSC^®, X-Pact^®  Profile and Flatness Control PFC^®, and the higher-level material tracking system. 

The existing mill stand will be retrofitted with a new twin drive that ensures the top and bottom work rolls can be operated independently. SMS group’s Genius CM^® system continuously provides data that is used to monitor the status of the drive unit and to carry out condition-based equipment maintenance. The new mill stand will also be equipped with independent AC motors for driving the top and bottom work rolls, double reduction gears, and drive shafts of the flat journal design with Genius CM^®.

Before being shipped, the automation system will be prepared and optimized for efficient commissioning as part of a Plug & Work integration test. This integration test enables faster commissioning and a quick start-up. After commissioning, the Nucor team will receive ongoing support from the SMS group experts via the X-Pact^® service portal.

This conversion will enable Nucor Steel to significantly increase its production capacity and get ready to meet future challenges in the steel industry.