Project Nanopflaster – Determination of the fatigue and corrosion resistance of Cu-Ni coatings on welded components

25/03/2025

• Challenge
• Objective
• Methods
• Partners + Funding

Offshore wind farms are essential to Germany's energy supply. The service life of wind turbines is crucial to their long-term economic viability. Their support structures are exposed to heavy loads and a corrosive marine environment, which leads to material fatigue and shortens their service life. The ‘Nanopflaster’ project addresses these challenges using nanolaminate coatings improving the fatigue strength and corrosion resistance of welded joints.

An existing nanolaminate coating for welds is being prepared for industrial use to extend the life of offshore wind turbines and reduce maintenance costs. The fatigue strength and corrosion resistance, as well as their interactions, will be investigated for the optimized coating. A solution for in-situ application will be developed and knowledge transfer to industry will be promoted. The project examines monopile and jacket foundations, to apply the technology to various offshore substructures.

Investigations into the fatigue strength and corrosion resistance of samples with optimized nanolaminate (ONL) are key focus areas of the project. In addition to tests for determining S-N curves, large-scale fatigue tests on 1:1.5 jacket joints will be conducted to evaluate the influence of the ONL at both the material and component levels. A central aspect of the corrosion studies will include 3D profilometric analyses after using various electrochemical corrosive degradation methods. These analyses aim not only to assess corrosion resistance but also to capture and describe the effects of corrosive damage processes on fatigue strength using condition models.

Project coordination:
TUHH Technical University of Hamburg

Partners:
Bundesanstalt für Materialforschung und -prüfung
JBO Jörss-Blunck-Ordemann GmbH
Steelwind Nordenham

Associated partners and project support committee:
AG der Dillinger Hüttenwerke
EnBW Energie Baden-Württemberg AG
RWE Offshore Wind GmbH
Salzgitter Mannesmann Forschung GmbH
Siemens Gamesa Renewable Energy GmbH
TÜV SÜD Industrie Service GmbH
Vestas Wind Systems A/S

Funding:
Bundesministerium für Wirtschaft und Klimaschutz

In the "Nanopflaster" project, the Bundesanstalt für Materialforschung und -prüfung (BAM) plays a central role in the development and validation of an innovative nanolaminate coating, which is intended to be optimized for use in offshore wind turbines. The focus of BAM is on the detailed analysis of the influence of these coatings on the fatigue strength and corrosion resistance of welded steel components. These components are particularly vulnerable to damage in structures of OWEAs and therefore represent critical weak points. The experimental investigations to be conducted at BAM are aimed at determining Wöhler curves for various weld details with and without nano-laminate coatings. To incorporate the corrosion damage mechanism, the same series of tests will be performed with specimens that were previously pre-corroded, for example, in a salt spray fog chamber. Special attention is therefore paid to the investigation of the combined effects of fatigue and corrosion. The effects of pitting corrosion will also be examined in detail, both with and without the optimized coating. The conducted methods include the use of electrochemical procedures and 3D profilometry for the precise analysis of corrosion processes and the surface condition of treated components. Another key component of BAM's work is the performance of large-scale fatigue tests on tubular joints, which are intended to enable the transfer of results. Additionally, BAM develops condition models for those damage mechanisms that can predict the service life of offshore structures, taking into account the combined effects of fatigue and corrosion. BAM also makes an important contribution to the standardization of the new concepts developed and to the integration of project results into industrial production processes. Through these comprehensive activities, BAM contributes to the development of sustainable and efficient offshore wind turbines.

Project partners

BAM, Division 7.2 Buildings and Structures and Division 7.6 Corrosion and Corrosion Protection

TUHH, Institute for Metal and Composite Structures
www.tuhh.de

JBO Jörss-Blunck-Ordemann GmbH
www.j-b-o.de

Steelwind Nordenham
en.steelwind-nordenham.de