Nucor-Yamato Steel Company (NYS), based in Blytheville, Arkansas, USA, has granted German plant builder SMS group a Final Acceptance Certificate for the successful modernization of NYS' heavy beam mill No. 2.
The new beam mill, which produces wide-flange beams and I-beams, was revamped to strengthen the steelmaker's leading position in the structural steel market sector, enabling NYS to expand its product range and increase its production and processing of high strength steel grades.
"The new stands are characterized by higher rolling forces, hydraulic adjustment under load and a fully automatic quick program change function."SMS group.
The modernization was focused on replacing existing conventional UR-E and UF stand arrangements with a compact three-stand tandem reversing mill of the CCS type (Compact Cartridge Stand) 1500. With CCS mill stands, both the old existing rolls and bearings can be used as well as the new rolls with larger bearing diameters, says SMS group. This reduces roll costs and represents a major advantage, it is claimed of the CCS design. As a result, NYS can produce heavier products and expand its portfolio.
"The scope of supply also includes roll shop equipment and a new automation system for real-time process control."SMS group.
According to SMS group, a hydraulic adjustment system of the bottom roll for the breakdown stand was supplied to improve flexibility in the rolling process; it allows the bottom roll to be adjusted from pass to pass, is used for roll force measurement as well as for overload protection and as a roll unjamming device. The scope of supply, claims SMS group, includes reinforced axial keeper plates for the breakdown stand that allow clearance-free axial clamping of the chocks.
"The revamp concept had been elaborated in detail already before the signing of the contract. In the SMS group test center in Mönchen-gladbach, Germany, the software and hardware to be supplied were tested and pre-optimized by means of a Plug & Work integration test."SMS group.
The revamp concept had been elaborated in detail already before the signing of the contract. In the SMS group test center in Mönchen-gladbach, Germany, the software and hardware to be supplied were tested and pre-optimized by means of a Plug & Work integration test. Thus, the commissioning effort on the site could be reduced and a rapid start-up curve of the production could be implemented.
"With only 16 days, the main shutdown for the revamp including the demolition of the old stands was tightly scheduled, and this tight schedule was strictly adhered to. The SMS team was there to support us throughout the entire execution phase of the project," said Jim Shelton, NYS' roll mill manager. "We are confident that this revamp will give us a decisive advantage in the market," he added.
"We are confident that this revamp will give us a decisive advantage in the market.”Jim Shelton, roll mill manager at NYS.
Despite COVID restrictions, the revamp was achieved on time and with a quick start-up of the plant thanks to the successful co-operation between NYS and SMS group.
A medium section mill operated by NYS at the same location, was modernized by SMS in 2014. The two rolling mills have an annual total capacity of 2.4Mt/yr of finished products.