Design ensures high-precision products, and high throughput
Arvedi Metalfer do Brasil Ltda. in Salto, Brazil, contracted SMS Meer earlier this year to supply a RD 140 HF welded tube plant with an integrated finishing line. Previously, a similar welded tube line was delivered by SMS Meer to Arvedi for its integrated steel plant at Cremona, Italy. The Brazilian project will begin operation in May 2013.
Arvedi is an Italian manufacturer of flat-rolled carbon steel, with subsidiaries producing welded tubular products. In 2008, the Arvedi Tubi Acciaio business unit took over Metalfer SpA, a producer of cold drawn tubes for automotive, hydraulic, mechanical, and pneumatic applications. Metalfer has three plants in Italy, one in Poland, and, since 2007, one in Brazil. Other Arvedi units include Ilta Inox, another welded tube producer, and Arinox, a producer of cold-rolled stainless steel strip.
"After our positive experience with the first welded tube plant, in terms of tube quality, flexibility and productivity, we decided to have SMS Meer set up a second welded tube plant,” according to Mario Caldonazzo, CEO of Arvedi Tubi Acciaio. “The finishing line also will be supplied by SMS Meer, with the result that we will have a fully integrated solution from a single source."
The new welded tube line will be designed to produce 150,000 metric tons/year of tubes in diameters ranging from 33.4 and 139.7 mm and wall thicknesses of 1.5 to 8.0 mm. Tube lengths range from 5.0 to 12.6 m.
The new welding line will reach a maximum production speed of 130 m/min. Arvedi Metalfer Do Brasil will be able to produce high-quality, thick-walled tubes with a round, square, or rectangular cross-sections, and these products may be used as shells for cold-drawn cylinders, structural pipe, low-pressure line pipe, castings, boiler tubes, or to form rear axles for commercial vehicles (HGVs). The products will match the most demanding commercial requirements, including EN 10219, API 5L, EN 10208, API 5CT, ASTM A513, and EN 10305, SMS noted.
SMS Meer is a multi-faceted engineering group and plant builder that includes welded tube plants among its area of specialization. Its offerings include welding lines for finished tubular products up to 26-in. diameter, including: strip preparation lines; strip cross welders; travelling strip cut-off unit; strip accumulator; strip edge millers; straightedge forming sections; rolling and squeeze stands; inside and outside scarfers; travelling saws and milling cut-off units; stand and roll changing systems for quick change-over of the lines; and computer-controlled roll setting and adjustment systems (CSS Quicksetting.)
Larger-dimension pipes (16-64 in. diameter) can be formed on SMS Meer lines that may include: edge milling machines; edge crimping presses; JCO pipe forming presses; three-roll bending machines; U-ing and O-ing presses; tack-welding stands; Internal and external welding stands; expanders; hydrostatic pipe testers; and chamfering machinery.
Michael Cottin, who heads SMS Meer’s Tube and Pipe Welding Plants unit, emphasized two particular benefits of the new Arvedi Metalfer installation: "The productivity of the plant is, on average, more than 30% higher than with conventional plants thanks to the innovative quick-change systems from SMS Meer.
“What's more, with this plant Arvedi can flexibly meet changes in market requirements for welded tubes,” Cottin continued. “Orders for increasingly small batch sizes with a variety of dimensions require plant solutions with short change-over times and minimal downtimes."
The core of the plant will be comprised of a conventional forming area with five breakdown stands, seven side-closing stands, and three finishing stands, in which the steel strip is formed into a precise open-seam tube. From there, it will be welded and deburred, conveyed through the cooling section, sized in four sizing stands, and brought to its precise final dimensions.
Changes for different tube dimensions may be implemented in under two hours, SMS noted, thanks to the inline and offline quick-changing systems it has developed. This involves the CSS Quicksetting technology — a computer-controlled system that ensures rolls are automatically adjusted to exact working positions after the size change. The roll stands are designed with closed frame plates, a design that SMS Meer indicated allows quick lateral changing of the roll chocks, and at the same time ensures high stability and thus high-precision during rolling.
Rolling forces are absorbed uniformly in both vertical and horizontal directions. The rigidity of the design is approximately 50% higher than for stands built with a pillar design, according to the plant builder. The two closed-frame plates make it possible to achieve close-tolerance tube dimensions, or to form thick-wall tubular products from high-strength steel grades.