Mechanisms and Impact of PITting on Carbon steel structures in a maritime environment
Context
Steel infrastructure is at the heart of the Blue Economy in Flanders, supporting critical sectors such as ports and offshore renewable energy. Offshore wind turbines, designed to last 20 to 25 years, face growing uncertainty due to corrosion damage. While standard strategies like coatings and cathodic protection address uniform corrosion, pitting corrosion remains poorly understood and rarely accounted for in lifetime assessments.
Pitting corrosion leads to small, localized holes that can act as crack initiation points, significantly reducing the fatigue life of steel structures. Current inspection methods are labor-intensive and unreliable. Detecting pitting earlier and more effectively is essential to improve maintenance planning and asset longevity.
Objectives and approach
The PIT project aims to improve the fundamental understanding of pitting corrosion in maritime environments and develop methods to monitor and quantify it.
The focus is on:
- Identifying conditions under which pitting occurs in carbon steel
- Determining pit shape, size, growth rate, and distribution
- Developing electrochemical monitoring techniques for real-time detection
- Automating corrosion coupon analysis to make assessments operator-independent
- Translating corrosion data into useful inputs for existing fatigue lifetime models
Although PIT does not develop new fatigue models, it enhances the accuracy of existing ones by providing better corrosion input data.
Research activities include:
- Lab and field testing of electrochemical techniques such as ECN, EFM, and EIS, with trials at the Harbour of Ostend
- Automated analysis of corrosion coupons using a large dataset collected from diverse exposure conditions
- Study of macrofouling impact, using floating pontoons and microprobe sensors to examine the environmental conditions beneath biofouling layers
- Mapping fatigue model requirements, ensuring that the developed monitoring methods deliver the correct input for more accurate fatigue assessments
Expected impact
The PIT project will deliver four Key Exploitable Results:
- Improved understanding of when and where pitting occurs, including the role of cathodic protection
- Electrochemical principles for detecting pitting, supporting real-time monitoring and sensor development
- Quantitative methods for pit characterization, enabling better fatigue life estimations
- A large dataset on pitting evolution in offshore steel, supporting improved designs and validated corrosion models
These outcomes will lead to reduced inspection and maintenance costs, more reliable lifetime assessments, and optimized material use for offshore and maritime steel structures.
Funding
- PIT is funded by VLAIO through the Cluster SBO programme, coordinated by the Blue Cluster.
- Project type: Cluster SBO
- Contract number: HBC.2024.0692
- Funding level: 100 percent
Partners
In collaboration with
