eDrive, one of the newest technologies by Primetals Technologies for bar and wire rod producers, has further enhanced the capabilities of legacy products like the Morgan No-Twist® Mill and the Morgan Reducing/Sizing Mill. Senior Engineering Manager and Head of Technology for Long Rolling, Matthew Palfreman, sat down with us to provide an overview of eDrive and how this technology directly benefits long product producers.
As someone involved in creating eDrive, what prompted the need for this new technology?
Matthew Palfreman: The steel industry is constantly evolving, and it’s our job to ensure we’re not only keeping up with shifting trends but staying ahead of the curve, so to speak. This means developing products and technologies that enhance overall mill efficiency and minimize costs. The eDrive addresses these growing needs by utilizing individually driven mill stands, which allow infinite processing flexibility per stand, increasing product quality and reducing CAPEX and OPEX.
How does eDrive improve bar and wire rod mill operation and product quality?
Palfreman: It begins with improved process control. Since eDrive utilizes individually driven mill stands, there are no longer any fixed ratios between stands, allowing roll pass engineers greater roll pass flexibility. This, in turn, allows greater freedom to remove tension within the machine. Removing tension improves the product’s dimensional stability from the mill, increasing yield and controlling tensile uniformity within a coil. The eDrive’s increased capacity also allows rolling at lower temperatures. This contributes to optimum grain structure, enabling bar and wire rod mills to improve product quality and reduce conversion costs.
The eDrive’s increased capacity also allows rolling at lower temperatures. This contributes to optimum grain structure, enabling bar and wire rod mills to improve product quality and reduce conversion costs.”
How does eDrive help facilitate thermomechanical rolling?
Palfreman: eDrive’s individually driven mill stands have a higher separating force and torque capacity. This allows rolling at lower temperatures over more extensive size ranges for a given stand size. Rolling at a lower temperature can control the recrystallization of grain growth and phase transformation while improving strength and ductility. The lower temperature is also beneficial, as higher cooling rates can be applied for certain materials with a risk of bainite-martensite formation.
The first eDrive No-Twist® Mill at ArcelorMittal Sosnowiec, Poland, was hot commissioned in 2018. Its rolling temperatures reached 750°C, ensuring ample conditions for our customers to produce high-carbon and quality steel-finished billets.
Our recent combination bar and rod mill installation at Baoshan Iron and Steel incorporated eDrive as part of a mini-finishing mill. Can you expand on this? How will this impact Baoshan’s production capabilities?
Palfreman: As mentioned above, the ability to roll at lower temperatures will allow greater process flexibility and the potential to improve product quality by refining and controlling the grain structure of the rod. It may eliminate some downstream processing, reducing the conversion costs of specific material types. There is also the added advantage of reduced roll inventory since machine roll families are no longer required, further reducing customer costs.
The next step for Primetals Technologies is to finalize the eDrive Reducing/Sizing Mill development to leverage the advantages discussed above.”
What does the future of eDrive look like?
Palfreman: The next step for Primetals Technologies is to finalize the eDrive Reducing/Sizing Mill development to leverage the advantages discussed above. The eDrive Reducing/Sizing Mill will be a machine different from the traditional Reducing/Sizing Mill. The eDrive Reducing/Sizing Mill will allow customers a ‘phased approach’ to precision high-speed rolling. In phase one, the customer can opt to install the reducing section of the machine to benefit from increased rolling speeds and then later install the sizing mill that will then allow the customer to produce wire rods with tolerances of 0.1 mm or better throughout the size range of a wire rod mill.
With no fundamental limitation on internal gear ratios, customers will be able to develop new process routes to improve existing material properties more easily. This could also allow our customers to produce new material grades or roll grades that were unachievable for them in the past.