Technology & Steel Application - News

Posted on 19 Jul 2017

Direct Quenching innovations at Nucor Tuscaloosa

Danieli installs world first DQ system downstream Plate/Steckel mill


Modern DQ systems are intended to produce a finer ferrite-bainite microstructure in the rolled product, while limiting or preventing pearlite formation. This achieves savings in alloy consumption and improves finished steel properties overall, to match the typical requirements for shipbuilding grades, pipeline grades for extreme applications, pressure vessel grades, etc.


The distinctive characteristic of the DQ application at Nucor Tuscaloosa is that it operates for the entire range of strip and plate thicknesses (4.76 to 63.5 mm) and on all the steel grades produced there.


Moreover, the new cooling rates now available open the opportunity for Nucor to develop new steel grades, e.g., bainitic steel grades for improved toughness, wear-resistant steel grades, and martensitic steel grades.


Danieli Automation supplied the unique automation and process control system needed for fully automatic set-up of all plant units to match the technological requirements of strip/plate cooling that will ensure their required metallurgical properties.


Also included in the package is the CQE-Coil Quality Estimator system, a mathematical model for predicting product’s mechanical properties in real time.


Hot tests and commissioning were carried out during normal production.