Key Words: Internal Coating, EHLA, Corrosion and Wear Protection Coating, Sustainability, Hydrogen

EHLA Internal Coating of Pipelines Against Hydrogen Corrosion

Extreme high-speed laser cladding (EHLA) is already used industrially as an economical and sustainable coating technology for external surfaces of rotationally symmetric components. The EHLA processes’ characteristics, such as high productivity, resource efficiency and an almost free choice of materials, offers new possibilities for the individual functionalization of surfaces. In addition, it can be used as a replacement process for chromium VI coatings, which are banned by the REACH regulation. The advantages of the EHLA process are enormous. As a result, more than 30 EHLA industrial plants have been put into operation since the patent was granted.

Now, the DAP chair further develops the EHLA hardware and process in order to make it ready for internal coating of hollow shafts. A major focus is on the internal coating of pipelines, for example, for the transport of hydrogen. The use of hydrogen as an energy carrier is one of the most promising concepts to achieve climate targets.

The main advantages of hydrogen are, among others, the local generation using renewable energies, transportability and energy storage. Compared to the concept of direct power generation as well as distribution, hydrogen can theoretically be transported and distributed via the existing gas grid. However, the existing pipelines used in the transmission network are susceptible to hydrogen corrosion, which increases brittleness and, thus, reduces service life.

For the application of the existing pipeline infrastructure to transport 100% hydrogen, the DAP chair develops an internal coating by means of EHLA within the framework of the Zukunftscluster Wasserstoff.
With this process, dense and metallurgically bonded coatings can be produced, making this the ideal technology for producing gas-tight coatings.

The Zukunftscluster Wasserstoff is funded by the BMBF.