In a significant stride towards enhancing the durability of marine vessels, researchers have developed a novel coating that shows promising corrosion resistance in acidic environments. The study, led by Han Lele from the College of Ocean Science and Engineering at Shanghai Maritime University, focuses on laser cladding technology to create cobalt-based composite coatings reinforced with spherical tungsten boride (WB).
The research, published in the journal ‘High Temperature Materials and Processes’ (translated from Chinese), investigated two specific compositions: Co + 15% WB and Co + 45% WB. The coatings were tested in a low-temperature hydrochloric acid environment to understand how the WB content affects their corrosion resistance.
The findings revealed that all coatings, including pure cobalt, Co + 15% WB, and Co + 45% WB, displayed passivation behavior in a 0.5 mol·L−1 HCl solution. Notably, the Co + 15% WB coating stood out, exhibiting the highest corrosion potential and the lowest corrosion current density. This composition also showed superior passive film resistance, charge transfer resistance, and film resistance, indicating optimal protective performance in acidic environments.
Han Lele explained, “The passivation range for WB-containing coatings was predominantly observed between −0.1 V and 0.2 V. This suggests that the coatings can form a protective layer that prevents further corrosion, which is crucial for marine vessels operating in harsh, acidic conditions.”
In contrast, the EH40 substrate, a common material used in marine applications, showed significant corrosion susceptibility. The corrosion process was primarily dominated by anodic dissolution, highlighting the need for effective coatings to protect the substrate.
The commercial implications of this research are substantial. Marine vessels often operate in corrosive environments, leading to frequent maintenance and repair costs. The development of these advanced coatings can significantly extend the lifespan of marine structures, reduce maintenance costs, and enhance safety.
Moreover, the findings provide valuable insights for the design and optimization of corrosion-resistant coatings. As Han Lele noted, “These results offer a foundation for future research and development in the field of marine coatings, potentially leading to more innovative and effective solutions.”
For maritime professionals, this research underscores the importance of investing in advanced materials and technologies to combat corrosion. By adopting these coatings, shipping companies and naval operations can improve the durability and reliability of their vessels, ultimately leading to more efficient and cost-effective operations.
In summary, the study by Han Lele and colleagues represents a significant advancement in the field of marine corrosion resistance. The development of these WB-reinforced cobalt-based coatings offers a promising solution to the challenges posed by acidic environments, paving the way for more resilient and long-lasting marine structures.