Effects of macro- and micro-fouling on the corrosion of marine grade metals
Abstract
While there have been studies and reports on how hard and soft fouling can affect corrosion, it is still a relatively under-researched topic, especially given the rate of associated attack that can occur. To date, the vast majority of research has been performed in the field with limited control over the extent and type fouling that forms. As such, it can be difficult to distinguish the specific mechanisms responsible for the associated material deterioration. Researchers have suggested that a combination macrofouling and the presence of certain microorganisms may lead to accelerated corrosion of marine materials. While microbiologically influenced corrosion (MIC) is widely acknowledged for its potential for rapid localised corrosion, most of the previous work on macrofouling and corrosion has presented limited information about relevant microbiological aspects. Many of the works suggest that sulfide products or MIC may be contributing factors, yet present little detail to support these statements. To date, there does not appear to be any utilisation of advanced microbial analysis techniques, such as high-throughput DNA sequencing, that might provide important insights. In addition, examples of laboratory studies that combine MIC-related microbes with relevant physical macrofouling structures are limited and none in conditions that approximate natural seawater. The proposed work will include a combination of field and laboratory studies to investigate the combined effects of microorganisms and macrofouling on the corrosion of copper-nickel alloys. A major issue historically in similar research has been an inability to control the fouling conditions being studied and to separate the various affects taking place. This proposed study will include the development of mechanical analogues (i.e., artificial fouling assemblages) to simulate both hard and soft macrofouling cover, in an effort to decouple and measure biological versus morphological drivers of macrofouling-induced corrosion. Another key problem in this research space has been a lack of detailed studies examining the effect of interactions between the macro- and micro-fouling communities on metal corrosion as well as the role of deposited sediment in this process. The overall objectives of the proposed research include:-#Investigate correlations of corrosion relevant microorganisms with hard/soft fouling in field trials, as well as the associated corrosion.-#Development of mechanical analogues to simulate hard and soft macrofouling for field and laboratory tests,-#Perform laboratory tests using mechanical analogues to simulate the effect of hard/soft macrofouling on corrosion-relevant microorganisms,-#Simulate real-world test conditions in laboratory corrosion tests with fouling analogues. Anticipated outcomes from the proposed research includes:-#Better understanding of the biological versus morphological drivers of macrofouling-induced corrosion,-#The development of simple #rules of thumb# for macrofouling-corrosion as it pertains to type and level of fouling, as well as levels of sedimentation in the recipient environments,-#The development of novel lab and field-testing techniques for the ongoing investigation of macrofouling-related corrosion. The research proposed has been developed specifically with Navy relevant structures and applications in mind. The aim of this work is to provide information that will help Navy, wider maritime industries and researchers working on this topic in terms of:-#Guidance on appropriate monitoring strategies to assess fouling-induced corrosion,-#Development of novel test methodologies and protocols for future studies on this topic,-#Providing insights on suitable mitigation strategies needed to manage this problem.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 15, 2023
- Source ID
- N000142312324
Entities
People
- Scott Wade
Organizations
- Office of Naval Research
- Swinburne University of Technology
- United States Navy