German Collaboration Targets Steel Surfaces

“On the surface” the course of events have been positive since November 2014, when ThyssenKrupp Steel Europe AG (TKSE; Duisburg, Germany), the Fraunhofer Institute for Materials and Beam Technology (IWS; Dresden, Germany), and LIMO Lissotschenko Mikrooptik GmbH (Dortmund, Germany) initiated development work on a new laser technology that the partners will use to improve the properties of steel strip surfaces.

This collaboration is part of a research project by the German Federal Ministry of Education and Research (BMBF) and is scheduled to be completed by 2017. In November LIMO launched its largest joint research project to date by contributing €3.6 million to the BMBF OSLO project. This four-letter German project acronym stands for “surface-functionalized steel strip materials using laser surface treatment in a continuous wide-strip process.”

Together, TKSE, IWS and LIMO will research how the properties of ferrous steel strip materials can be influenced in a targeted manner by laser surface treatment in a continuous in-line wide-strip process. Materials experts refer to it as functionalizing: To provide steel with better corrosion protection, for example, the laser will uniformly heat the steel’s surface layers over the entire strip width. But corrosion protection is not the only benefit of this alloying or surface melting process: Thanks to uniform heating, it is also extremely energy-efficient and environmentally friendly, since the laser only heats the surface, rather than the entire volume of the wide strip.

The success of the OSLO project hinges on the laser system and beam shaping unit for the short-time heat treatment of the coated steel strip scheduled to be used in the demonstration machine at TKSE in Dortmund under conditions closely simulating real-life production (process speed is minimum 50 m/min, strip width of 300 mm).

“To enable these types of short-time surface treatments, a laser system never before available anywhere in the world has to create a length-scalable, uniform and extremely thin line of light,” says Dr. Jens Meinschien, the vice president of innovations management at LIMO. “To meet this challenge, we’re engineering a powerful 35 kW semiconductor laser featuring sophisticated beam shaping and high beam quality.” Using this new laser system, the OSLO project partners aim to develop a new type of laser surface treatment, and possibly bring it to maturity for an eventual series production.

For LIMO, it’s about more than just the biggest joint research project in the company’s history. Dr. Jens Meinschien adds, “Under the moniker ‘photonics industry meets steel industry’, this collaboration between big industry, small business and research delivers a synergy effect that will help secure Germany’s role as a center of steel manufacturing. LIMO plans to use OSLO to expand its position as a manufacturer of tools of light for large-area surface processing and is looking to position itself as a long-term supplier of the steel industry.”

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