ThyssenKrupp Acciai Speciali Terni in Italy says it is now one of only a few stainless steel mills worldwide to use innovative “S-6-high” rolling technology integrated on strip processing lines.
Following installation at the beginning of 2010 and completion of the ramp-up phase, the new two-stand rolling mill is now running at full capacity. It is positioned in the entry zone to the hot strip annealing and pickling line (LAC 10) and features small-diameter, laterally supported work rolls. The specific configuration of the stand is said to enable cold reductions up to 50% on the incoming black strip.
This method combines several processing steps in the stainless steel production process; tandem cold rolling, hot strip annealing and pickling are now integrated in the existing LAC 10 line, which eliminates the need for intermediate annealing.
ThyssenKrupp Acciai Speciali Terni says it can now market a product whose microstructure, mechanical properties, and geometric tolerances are virtually the same as a standard cold-rolled strip. This new product, called 2E-Finish (cold rolled, annealed, blasted, pickled, stretch leveled), is a lower-cost alternative to conventional 2D/2B (cold rolled, annealed, pickled/skin passed) finishes for some applications, the company claims.
The technology also allows hot strip to be produced in a greater range of sizes, according to ThyssenKrupp, and the process chain for cold strip is shortened through the combined rolling and annealing of hot strip. The reduction in hot strip thickness is also said to provide the hot rolling mill greater flexibility, resulting in increased productivity.
The S-6-high process is capable of producing cold rolled and annealed coils in 2D finish (cold rolled, annealed, pickled) directly from the LAC10 by a double passage on the line.
“Our customers also profit directly from these technical innovations: The more compact production cycle shortens our delivery times and distinctly improves strip thickness and flatness tolerances,” said Alessandro Segala, head of the Metallurgy and Innovations department at ThyssenKrupp Acciai Speciali Terni. “This 6-S-high process is the state-of-the-art in terms of process development. It has enabled us to significantly strengthen our competitive position.”
ThyssenKrupp Acciai Speciali Terni is one of the world’s leading manufacturers of stainless steel flat products. As well as the service centers of Terninox, the company has manufacturing subsidiaries in Tubificio di Terni and Società delle Fucine. In fiscal year 2008/09, it generated sales of around 1.7 billion euros.