Breakthrough in overcoming tribocorrosion in marine metals!

 A joint research team led by Dr. Young-Jun Jang and Dr. Jongkuk Kim of the Extreme Materials Research Institute, in collaboration with Dr. Sungmo Moon’s team from the Energy and Environment Materials Research Division at the Korea Institute of Materials Science (KIMS) has successfully developed Korea’s first high corrosion- and wear-resistant carbon coating technology to mitigate the severe corrosion and wear issues associated with ammonia fuel. This technology is expected to serve as a key enabling platform for accelerating the commercialization of eco-friendly ammonia-powered ships.

 Conventional marine metallic materials, such as stainless steel 440C, are well known to undergo repeated degradation during long-term operation due to the strong alkalinity and chemical reactivity of ammonia. These conditions lead to the breakdown of surface oxide layers, as well as localized corrosion and wear. In particular, fuel-contacting components such as engines, valves, pumps, and bearings have been shown, through experimental and demonstration studies, to exhibit clear structural vulnerabilities. As a result, securing highly corrosion-resistant surface technologies has become a critical requirement during the design and classification certification stages of ammonia-powered ships.

  The carbon coating technology (ta-C:Hx) developed by the research team for eco-friendly ammonia-fueled ships is a highly corrosion-resistant surface protection technology that effectively suppresses rapid metal corrosion and wear in ammonia fuel environments over a wide temperature range, from cryogenic to medium- and low-temperature regimes. While conventional marine materials exhibit corrosion current densities of approximately 48 μA/cm² in ammonia solutions, the newly developed coating reduces the corrosion current density to 4 μA/cm², corresponding to an approximate 92% reduction. In addition, the corrosive wear rate was significantly reduced from 1.4 × 10-6 mm3/N·m for conventional SS440C to 1.3 × 10-8 mm3/N·m for the developed coating, achieving a 99.1% reduction in tribocorrosion wear test under ammonia solutions.

  Conventional nitride coatings and wet plating layers, which have traditionally been used in marine applications, are primarily optimized for seawater, atmospheric, and other general industrial environments. However, their long-term reliability under highly alkaline and chemically reactive fuel environments, such as ammonia, has not been adequately demonstrated. In particular, due to inherent process-related characteristics, plating and nitride layers are prone to pores, thickness non-uniformity, and interfacial defects. In highly corrosive environments, these defects can act as initiation sites for corrosion. 

 The key innovation of the newly developed technology lies in the purposeful engineering of the coating process specifically for ammonia environments. Through the application of pulsed bias control in a filtered arc deposition process, micropores and interfacial defects were effectively minimized. Furthermore, by introducing hydrogen to regulate the internal structure and electrical properties of the coating, a stable carbon structure was formed, enabling the suppression of corrosion reactions even in aqueous ammonia solutions. This technology is currently evaluated as the only domestically developed surface coating technology in Korea capable of meeting the corrosion resistance requirements for the design and classification certification of ammonia-powered ships.

 Under the “2023 IMO Greenhouse Gas Reduction Strategy,” the International Maritime Organization (IMO) requires that a specified proportion of fuels used in international shipping be transitioned to zero-carbon alternatives by 2030. In addition, the Maritime Safety Committee (MSC) has approved interim guidelines for ammonia-fueled ships, formally requiring the verification of corrosion resistance for metallic materials used in fuel systems. In advanced maritime nations such as Japan, Norway, and Singapore, demonstration projects for ammonia-powered vessels are actively being conducted to evaluate the corrosion and wear performance of metallic components.

South Korea has designated ammonia-powered ships as a strategic sector for the shipbuilding and shipping industries through the “2050 Green Shipping National Action Plan” and the “K-Ammonia Eco-Friendly Ship Promotion Strategy.” However, despite domestic shipbuilders securing Approval in Principle (AiP) for ammonia-powered vessel designs, the lack of domestically developed surface coating technologies capable of reliable operation under highly corrosive environments remains a key barrier to commercialization.

The newly developed technology builds upon KIMS’s accumulated expertise in carbon coating technologies and environmental corrosion evaluation capabilities established through its in-house research programs. By advancing ammonia-specific corrosion-resistant coating technology, KIMS has demonstrated strong technological competitiveness capable of meeting the corrosion resistance requirements imposed by ammonia fuel systems in practical applications.

 Dr. Young-Jun Jang, Principal Researcher and lead investigator of the project, stated, “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 added, “A key feature of this work is that 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 not only to strengthening the domestic industrial ecosystem but also to expanding into the global market in the future.”

 This research was supported by KIMS’s in-house research program, “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 research findings were published online on December 1, 2025, in the internationally renowned journal Carbon (Impact Factor: 11.6).

 The research team is currently conducting process stabilization and repeated reliability evaluations of the coating technology for ammonia fuel environments, while simultaneously carrying out follow-up demonstration studies for application to actual ship components. In addition, based on these research outcomes, the team is pursuing additional patent filings and plans to actively explore opportunities for technology transfer and commercialization through collaboration with industry partners.

###

About Korea Institute of Materials Science(KIMS)

KIMS is a non-profit government-funded research institute under the Ministry of Science and ICT of the Republic of Korea. As the only institute specializing in comprehensive materials technologies in Korea, KIMS has contributed to Korean industry by carrying out a wide range of activities related to materials science including R&D, inspection, testing&evaluation, and technology support.