A research team from South Korea has made significant strides in combating tribocorrosion in marine metals. Led by Dr. Young-Jun Jang and Dr. Jongkuk Kim from the Extreme Materials Research Institute, in collaboration with Dr. Sungmo Moon from the Korea Institute of Materials Science (KIMS), the team has developed a high corrosion- and wear-resistant carbon coating technology. This innovation addresses critical issues associated with ammonia fuel, marking a potential turning point for the commercialization of eco-friendly ammonia-powered vessels.
Conventional marine metals, particularly stainless steel 440C, face severe degradation during prolonged exposure to ammonia. The substance’s high alkalinity and chemical reactivity can lead to the breakdown of protective oxide layers, resulting in localized corrosion and wear. Components that come into direct contact with fuel, such as engines, valves, pumps, and bearings, have shown particular susceptibility to structural vulnerabilities. As a result, enhancing corrosion resistance in surface technologies has become essential for the design and certification of ammonia-powered ships.
The newly developed carbon coating technology, known as ta-C:Hx, presents a robust solution. It exhibits remarkable corrosion resistance that significantly reduces metal corrosion and wear in ammonia environments across a wide temperature range, from cryogenic to medium and low temperatures. Traditional marine materials demonstrate corrosion current densities of around 48 μA/cm2 in ammonia solutions; however, the new coating reduces this to 4 μA/cm2, achieving a reduction of approximately 92%. Additionally, the corrosive wear rate has plummeted from 1.4 × 10-6 mm3/N·m for SS440C to 1.3 × 10-8 mm3/N·m for the new coating, resulting in an impressive 99.1% reduction in tribocorrosion.
Traditional coatings, such as nitride coatings and wet plating, have primarily been optimized for seawater and general industrial environments. Yet, their performance in highly alkaline and chemically reactive conditions, such as those found with ammonia, remains unproven. The new technology represents a crucial advance, specifically engineered to perform under these challenging conditions. By employing pulsed bias control in a filtered arc deposition process, the team effectively minimized micropores and interfacial defects, which could otherwise serve as initiation points for corrosion.
The innovation is recognized as the only domestically developed surface coating technology in South Korea capable of meeting the corrosion resistance specifications required for the design and classification of ammonia-powered vessels. The International Maritime Organization (IMO) has initiated the 2023 Greenhouse Gas Reduction Strategy, mandating that a certain percentage of fuels used in international shipping transition to zero-carbon alternatives by 2030. Furthermore, the Maritime Safety Committee (MSC) has established interim guidelines for ammonia-fueled ships, necessitating verification of corrosion resistance in materials utilized within fuel systems.
Advanced maritime nations, including Japan, Norway, and Singapore, are actively conducting demonstration projects to assess the corrosion and wear performance of components in ammonia-powered vessels. South Korea has identified ammonia-powered ships as a strategic sector within its shipbuilding and shipping industries, as emphasized in the 2050 Green Shipping National Action Plan and the K-Ammonia Eco-Friendly Ship Promotion Strategy. Despite achieving Approval in Principle (AiP) for various ammonia-powered vessel designs, the absence of domestically developed surface coating technologies capable of functioning reliably in corrosive environments poses a significant barrier to commercialization.
The research builds on KIMS’s established expertise in carbon coating technologies and environmental corrosion evaluation. By focusing on ammonia-specific corrosion-resistant coatings, KIMS has demonstrated considerable technological competitiveness to meet the requirements of ammonia fuel systems in real-world applications.
Dr. Young-Jun Jang, Principal Researcher and lead investigator, remarked, “If this technology is commercialized, it will provide a practical solution for long-distance operation by significantly improving the efficiency and reliability of key components for eco-friendly shipbuilding and marine vessels.” Co-researchers Dr. Jongkuk Kim and Dr. Sungmo Moon highlighted the collaborative efforts that led to this achievement, stating, “The technology was advanced through close collaboration among KIMS’s internal technologies and research infrastructure, rather than relying on external technology adoption. We expect this achievement to contribute to strengthening the domestic industrial ecosystem and expanding into the global market.”
The research was supported by KIMS’s in-house program titled “Development of Practical Tribology Technologies for Cryogenic Environments” and by the National Research Foundation of Korea (NRF) through the Nano and Materials Technology Development Program funded by the Ministry of Science and ICT. The findings were published online on December 1, 2025, in the acclaimed journal Carbon (Impact Factor: 11.6).
The research team is currently focused on stabilizing the coating process and conducting reliability evaluations for ammonia fuel environments. They are also pursuing follow-up studies for application to actual ship components and exploring opportunities for technology transfer and commercialization through partnerships with industry stakeholders.
