The marine transmission to be seen here was still traditionally produced using the casting method. Laser-assisted arc welding could be an alternative in the future | Photo: Reintjes GmbH
Marine gear units are unique pieces that have been produced using the casting process up to now. In the future the large and heavy components could be produced by laser-assisted arc welding | Photo: Reintjes GmbH


Printing instead of casting

Technology | 3D printing for large steel parts in development

The starting point for the project which is funded by the Federal Ministry of Economics are housings for marine transmissions that are unique and have been produced using the casting process up to now. A process that is not only complex but also produces massive and thus very heavy and resource-intensive parts.

The additive production would offer considerable advantages, as well as eliminating the need for mold making the design could be optimized to suit the process. The integration of cavities and wall thickness optimization would reduce material requirements. The project team assumes that a steel housing currently weighing 13 tons would only weigh 10 tons after optimization for additive production.


Arc Welding

The process is based on laser-supported arc welding in which steel wire is melted and layer after layer is placed on top of each other. To ensure that large parts can be produced in an acceptable time the project aims to achieve an hourly throughput of 5 kilograms of steel. The necessary printing space is also beyond the dimensions of 3D printing, it would have to be 6 meters long, 3 meters wide and 1.5 meters high.


Quality control included

While the Laser Zentrum Hannover e.V. is dedicated to this aspect the Institute for Integrated Production Hannover is working on quality management. Inline measurement technology is used to detect errors during the printing process and automatically correct the printing parameters.

In addition to the two institutes four other partners are involved. The research project which will run until the end of 2021 is being led by the marine transmission manufacturer Reintjes.


Problems with tension

In addition to the size of the installation space, there is a far more complex problem to be solved: stresses in the component caused by shrinkage processes during cooling.


Source: Institut für Integrierte Produktion gGmbH, Hannover

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