The federal state government of North Rhine-Westphalia, Germany, has launched the NRW Leitmarkt project AddSteel, aimed at digitalising the steel industry. Coordinated by SMS group GmbH, Mönchengladbach, Germany, the three-year project aims to develop new function-adapted steel materials for Additive Manufacturing.
One of the project’s key areas of focus is the qualification of newly developed materials for Laser Powder Bed Fusion (L-PBF) at the Fraunhofer Institute for Laser Technology (ILT) in Aachen, Germany. One of the AddSteel project team’s first reported successes was the development of case-hardening and heat-treatable steel powders designed specifically for L-PBF applications.
According to Fraunhofer ILT, steelmakers in Germany are facing a continuing decline in sales. Previously, efficiency was increased by modifying manufacturing processes and equipment. Now, however, developers and users are increasingly turning their focus to the alloys to be processed. Innovative materials are expected to offer new potential for competitive advantages.
The steel industry requires new materials to meet its customers’ increasingly complex demands for products they can use, for instance, to manufacture lightweight and crash-resistant components for the automotive sector. AM processes such as L-PBF are extremely useful for lightweighting and part optimisation, and give users the opportunity to sustainably optimise the steel industry’s value chain.
In recent years, scientists at Fraunhofer ILT have been working on developing L-PBF technology from a prototyping method to an industrial-scale method for the production of complex parts in small series. L-PBF is already being used by companies in the aerospace, turbomachinery, medical device and other industries to produce complex functional components.
However, it is not currently possible to produce case-hardening and heat-treatable steel components using L-PBF, due to the lack of suitably qualified and certified materials that would enable components to be additively manufactured in the L-PBF process without forming cracks or defects. Such materials are either unavailable or not yet available in sufficient quantities for industrial manufacturing.
According to Fraunhofer ILT, modifying L-PBF processes and equipment is not enough to tackle this challenge, because the alloy composition of the case-hardening and heat-treatable steel materials currently used is specifically adapted to conventional manufacturing techniques. Hence, new steel materials must be developed specifically for L-PBF.
The AddSteel project partners have reportedly chosen to develop alloys in an iterative process, combined with systematic adjustments to the L-PBF process and equipment. This will be followed by the construction of technology demonstrators for the fabrication of new components and spare parts that will be used to test and validate the materials’ performance and cost-efficiency.
“A plant has already been built at SMS group that can atomise suitable metal powders,” reported Andreas Vogelpoth, a member of the Laser Powder Bed Fusion Group and head of the AddSteel project at Fraunhofer ILT. “Deutsche Edelstahlwerke Specialty Steel is now supplying the new alloys that Fraunhofer ILT will soon be testing on its L-PBF system, after the alloys have been converted into powder form.”
The AddSteel project has been granted funding for a period of three years by the European Union and the state of North Rhine-Westphalia. In addition to SMS Group and Fraunhofer ILT, the project’s four participants include Deutsche Edelstahlwerke Specialty Steel GmbH & Co. KG Fraunhofer ILT spin-off Aconity GmbH.