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This is the second part of a description of the Lake Erie Works of Stelco, one of Canada's top steel producing companies. It is a greenfield site project using the traditional blast furnace/oxygen steelmaking route. In this article the construction and operation of the hot strip mill is investigated, and particular attention is paid to the control system.
The Lake Erie development hot strip mill is known as a Generation III mill, indicating that its design features powerful and innovative technology recently developed by Stelco. The hot strip mill produces high-quality strip and coils either to meet customer demand or to be processed further into cold rolled and coated products at Hilton Works in Hamilton.
This 80in (2050mm) hot strip mill is a modified semi-continuous type. A new process device, a coilbox installed between the roughing and finishing mills, will substantially reduce the capital cost of the mill while allowing it to be fairly competitive with modern, fully-continuous, high-speed strip mills.
The hot strip mill (fig 1) consists initially of one slab reheat furnace, a reversing rougher stand powered by a 12,000 horsepower main drive close-coupled with a 3000 horsepower vertical edger, a coilbox, crop shear, descaler, four-stand computer-controlled finishing train, laminar spray-type runout cooling table and a downcoiler capable of handling gauges up to 12.7mm (0.5in) and as thin as 1.52mm (O.OoOin). Finishing equipment consists of an 80in skin mill for the temper rolling of hot rolled coils and a hydrochloric acid pickle line for the cleaning of the strip.
The hot strip mill complex, for which Wean United Canada Ltd was the main contractor, is the largest on the Lake Erie development site, having a total building length of 674m (221 1ft). The excavation for the complex necessitated the removal of 1 5 1 ,000m3 ( 197,500 cu yds) of earth to form a basement 10m (33ft) deep, measuring 332m (1090ft) long by 40m (130ft wide).
Slabs for Lake Erie Works (LEW) are predominantly 240mm thick and 9.7m long. They are provided in 13 standard widths between 785 and 1880mm. The grades of steel rolled cover the full range of chemical compositions from plain carbon to higher strength alloy steels and "skelp" (steel strip for pipe manufacture). From this array of slabs...