Deutsche Edelstahlwerke has once again reinforced their position as a quality leader in the long specialty steel products segment. After investing approximately € 4.5 m in an additional, innovative bright steel production facility at their location in Hagen, the company is setting new standards in regard to process reliability and flexibility in the production of premium bar. The facilities which began operations in February 2016 consist of a bar-drawing line, two grinding machines and a crack-detection system. State-of-the-art technologies guarantee consistent quality that is reproducible at any time for a total bar length between two and 6.2m and diameters of five to 16 mm.
In addition to machinery and gear manufacturers, the chief customer for the bright steel bars made in Hagen is the automotive industry. "Our clients use the bar to manufacture high-quality valves, for example, that are built into highly efficient drive units. In keeping with the automotive industry's efforts to reduce the overall weight of the automobile, we see great potential for our valve steel in the future since not only more, but above all thinner valves are needed to reduce vehicle weight sustainably. Every gram counts. Yet to ensure that the thinner valves are still able to meet the requirements of an environment characterized by pressure, chemical fluids and high temperatures, selecting the right material is essential. Our technical customer support team in cooperation with the sub-suppliers and car manufacturers find the right special steel solution. With the new bar-drawing line, we ensure that our semi-finished product is manufactured as efficiently as possible in terms of time and still also fully meets the high quality requirements of our customers. This allows us to improve our delivery performance and make a contribution to process reliability and material efficiency at customer facilities," explains Oliver Bell, Chairman of the Management Board at Deutsche Edelstahlwerke. To provide quality and process reliability along the entire delivery chain is the declared objective of Deutsche Edelstahlwerke, a subsidiary of the international SCHMOLZ + BICKENBACH Group. To meet this goal, an innovative approach was taken in the design of the new bar-drawing line, specifically with respect to the selecting of the drawing unit. Whereas in the past, conventional cam machines were used to draw the bar, Deutsche Edelstahlwerke is now using a Danieli caterpillar drawing system in production. "With the caterpillar draw-off system we achieve a drawing force of a maximum seven tons and, with up to 100 m per minute, a much higher drawing speed than with the previous process. At the same time, this caterpillar drawing technology allows us to produce uniformly thinner and top-quality bar despite these speeds. And we still achieve greater process reliability," explains Thomas Möller, technical manager at the Hagen site. Deutsche Edelstahlwerke generally uses 5.5 to 30 mm rolled wire made of stainless, acid and heat resistant steel, tool and engineering steel. "We use high-alloy stainless, acid and heat resistant steel in over 50% of our bar, including the valve steel for the automotive industry. One example is Pyrodur® 4718, our most popular steel for intake valves in the dimensional range between 4.8 and 24.0 mm. The steel with a surface hardness on the finished valve is impressive at over 60 HRC," says Möller. "We are the first steel producer in Europe to use caterpillar drawing to produce high-alloy stainless, acid and heat resistant steel bar. And it has been obvious since the plant started operations that we made the right decision. Before investing, our specialists ran extensive pilot tests and held technical discussions whether the use of the caterpillar drawing technology would actually be appropriate for the intended use and also have additional positive effects. Our test runs and the products manufactured since operations began now confirm their studies."More flexibility and product-specific quality assurance
Yet only assured quality is top quality. This is behind Deutsche Edelstahlwerke's decision to add a state-of-the-art crack-detection system to the investment in the drawing line and the two new grinding machines with single bar function. This machine uses an eddy current test to detect surface flaws reliably, has a bar separator and was designed specifically to test thin bar.
Drawing, straightening, grinding, testing - the plants and machines are not the only new additions. The layout concept has also changed. Time-consuming transports between bar-drawing line and the machining and testing machines have been eliminated and transport itself is also more efficient and economical. Deutsche Edelstahlwerke has also designed the manufacturing areas in the production hall in such a way that even material that has not previously passed through the bar-drawing line can also be ground, inspected and tested at any time. This makes the company more flexible when processing customer orders and makes process sequences faster and smoother. "In-process inspection and testing of the material are possible as a rule during every stage of production along the bright steel line," says Mr. Möller.