14.05.2021. Benxi Iron & Steel (Benxi), China, has issued the Final Acceptance Certificate to SMS group for the modernisation of their 1,700-mm No. 1 hot-strip mill. The objective was to bring the mill’s production capacity and the production range – by adding high-strength steels – up to the requirements of the hot-strip market. Benxi again banked on the know-how, expertise and technology from SMS group for the project. Meanwhile it was the fifth comprehensive modernisation of the mill, which was first commissioned in 1987.
Modernisation
As a key part of the modernisation, three CVC®plus (Continuously Variable Crown) work-roll bending and shifting systems have been installed in the finishing stands F2 to F4, complete with the associated valve technology. These systems enhance the geometrical tolerances of the hot strip.
The optimisation measures performed on the rolling stands F2 to F4 comprised not only the mill stands themselves but also the inter-stand areas. Improved guides and new work-roll cooling systems have been installed on the entry sides of all three stands. The roll gap lubrication system, in combination with the optimised roll-gap cooling system, reduces the mechanical stresses (forces and torques) acting on the rolling stands, prolonging the roll lives as a result. Thanks to the resulting boost in performance capacity of the finishing stands F2 to F4, the mill can now also produce strip in high-strength grades.
Further, the back-up roll balancing systems in the finishing stands F1 to F7 have been upgraded by replacing the emulsion-based balancing hydraulics with oil hydraulics. This measure involved the replacement of the cylinders and the complete control system, including the connecting pipes and the piping within the stands. In addition, in stands F1 and F5 to F7, the work-roll locking systems on the operator side have been replaced by a reinforced design.
Benxi benefits from the modernisation in terms of enhanced mill availability, higher product quality and a more stable finish-rolling process.
“Based on the very good cooperation with SMS group in the past and their solutions, we entrusted SMS group also with this recent mill revamp. With SMS as our partner, we can be sure that our mill will always be up to date and that we can response to the growing requirements of the market in an economically efficient way,” says Song Dawei, Deputy Manager of the HSM#1 Equipment Department.
(Source: SMS group)
