The core of the project at Nucor involves the conversion of the existing plant into a state-of-the-art tandem Steckel mill. To enhance the mill’s ability to produce thin, high-strength products, an additional high-performance rolling stand will be added downstream of the existing stand, creating a tandem Steckel line. Both stands will be used simultaneously for reversing roughing passes and finishing passes. The tandem arrangement of the stands also allows for the use of special work rolls in one stand for the production of floor plates and chequered sheets.
The existing entry and exit Steckel furnaces will be replaced by new, modern furnaces with a closed bottom design. These modern furnaces efficiently maintain product temperature and protect the roller tables from heat radiation. The improved efficiency of the furnaces reduces natural gas consumption.
Rolling Stands
After the conversion, both rolling stands will be equipped with CVC® plus technology to ensure the highest strip quality. CVC® is a powerful tool for controlling strip profile and flatness by combining roll bending and axial shifting of the work rolls with a specially designed contour.
A looping tower positioned between the stands optimizes strip tension and supports speed control.
System Supplier for Modernization
In addition, SMS group is responsible for the modernization of the Steckel mill’s electrical and automation systems, including the main drives, sensors, measurement devices, and instrumentation, as well as the basic and process automation of the plant.
With the modularized Level-1 software architecture, the system responds very quickly to demands and ensures flawless production performance. For example, the stability of the rolling process and strip guidance is improved through SMS group’s X-Pact® Centerline Control with intelligent cameras and control functions of Level-1 automation, enabling highly automated strip control. Level-2 process automation includes the technological process models X-Pact® Pass Schedule Calculation PSC®, X-Pact® Profile and Flatness Control PFC®, and the overarching material tracking system.
The existing rolling stand will be retrofitted with a new twin-drive system for independent operation of the upper and lower work rolls. The SMS group Genius CM® system continuously provides data to monitor the condition of the drive system and to enable condition-based maintenance of the equipment. The new rolling stand will also be equipped with independent AC motors to drive the upper and lower work rolls, double-reduction gear units, and flat-spindle drive shafts with Genius CM®.
Integration Test for Nucor
Before shipment, the automation system will undergo a Plug & Work integration test to prepare and optimize it for efficient commissioning. This integration test allows for faster commissioning and rapid startup. After commissioning, the Nucor team will receive support from SMS group experts through the X-Pact® service portal.
This transformation will enable Nucor Steel to significantly increase its production capacity and better prepare for future challenges in the steel industry.
