TPT November 2011

A rticle

Experiences gathered in the operation of the 12¾" tube welding plant By Frank Lagac, SMS-Meer GmbH and M Caldonazzo, Arvedi Tubi Acciaio SpA

Summary Minimised changing times, high flexibility, superior quality and challenging products. These were requirements of Arvedi Tubi Acciaio for the investment in a new 12¾" ERW tube welding line for large wall thicknesses. The chosen supplier was SMS Meer, Germany. The following article shows the technical details and how the expectations were achieved. The first production results are very positive and prove that the expectations were fulfilled. 1. Arvedi Tubi, brief survey The core business of the Arvedi group comprises the steelmaking industry and the processing of carbon and stainless steel products. In 2010, steel production (hot rolled coils) amounted to approx. 2.3 million tons and consolidated turnover to approx. €1.8 billion. The Group employs about 2,000 people. Arvedi Tubi Acciaio is the branch which produces carbon steel welded tubes. The factory, located in Cremona, Italy, was founded in the early 70s and is equipped with state-of-the-art manufacturing facilities. The company concentrates on the production of quality and special products and has a leading position on both the domestic and the European markets. Arvedi Tubi Acciaio is equipped with a hot stretch reducing mill and five lines for ERW tubes and has an annual production capacity of 600,000 tons. The product mix comprises round tubes from 17mm to 323.9mm as well as the corresponding square and rectangular tubes. The products are mainly used in the automotive, petrochemical, thermal, construction and mechanical industries. Arvedi Tubi Acciaio is the majority shareholder of Metalfer, the most important Italian and one of the most significant European manufacturers of cold drawn tubes destined for the automotive and hydraulics market.

Arvedi planned to extend the formerly produced maximum dimension of 168.3 x 12.7mm to 323.9 x 16.0mm. In addition, the plant was intended to serve for the production of smaller dimensions with larger wall thicknesses. With the plant, Arvedi intended to focus on high-quality and special products in the boiler pipe, line pipe, hollows for cold drawn tube such as hydraulic cylinders and thick-walled construction pipe ranges of both round and special section sizes. The plant must be designed for rigid, smooth operation, and, at the same time, meet all the demands placed on a state-of-the-art plant, in particular • above-average product quality • high yield • highest possible production flexibility

• high production speeds • short size changing times • high level of automation • easy and reliable operation, which are to be fulfilled by the plant technology.

To achieve the mentioned targets, SMS Meer was selected as the plant supplier, in order to coordinate the plant equipment concept and execution in close cooperation between the customer and the supplier.

3. Plant manufacturer’s implementation concept In order to fulfil the customer’s expectations, SMS Meer combined existing proven equipment with completely new solutions. A high production capacity at a maximum speed of up to 60m/min requires adequately fast and automated units.

Figure 1: Strip preparation and spiral strip accumulator

2. Customer’s expectation In 2007 Arvedi started to plan the expansion of its production capacity by means of a new tube welding plant. With the new plant, Arvedi intended to increase its product mix with respect to dimensions and products (Figure 11: full scale and Figure 12: blue marked area).

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N ovember 2011

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