- A consortium led by ClassNK has been selected by NEDO to develop evaluation tools for stress corrosion cracking (SCC) in fuel ammonia tanks and transport systems.
- The project involves studying the SCC mechanisms in steel exposed to liquid ammonia, followed by tool development and stakeholder consultation for risk-based maintenance procedures.
- This initiative supports Japan’s Green Growth Strategy by ensuring the safe use of ammonia as a zero-carbon fuel for power plants and ships.
ClassNK, in collaboration with IHI Corporation, JFE Steel Corporation, Tohoku University, and the Institute of Science Tokyo, has launched a new project to develop tools for evaluating the probability of stress corrosion cracking (SCC) in fuel ammonia storage tanks and transportation equipment. The initiative was selected by Japan’s New Energy and Industrial Technology Development Organization (NEDO) under its Feasibility Study Program on Energy and New Environmental Technology. Following the project’s approval in May 2025, an outsourcing agreement was recently finalized with NEDO.
Focus on Mechanism Research and Tool Development
The consortium will begin by conducting an in-depth investigation into the mechanism of SCC, which occurs when steel is exposed to the combined effects of mechanical stress and corrosion from liquid ammonia. Based on these findings, the team will work toward developing practical and precise tools to assess the probability of SCC. These tools aim to support more reliable inspection, maintenance, and operation practices.
Engagement with Industry and Risk-Based Maintenance Planning
To ensure broad applicability and safety in real-world scenarios, the consortium will seek feedback from industry stakeholders. These insights will help in creating comprehensive, risk-based maintenance procedures for fuel ammonia infrastructure, including marine fuel tanks. The overarching goal is to foster safer, more efficient practices to enable the broader adoption of ammonia as a marine and industrial fuel.
Ammonia’s Role in Japan’s Decarbonization Strategy
Ammonia is regarded as a promising alternative fuel due to its carbon-free combustion. It plays a vital role in Japan’s Green Growth Strategy, especially for decarbonizing thermal power plants and marine vessels. However, the SCC risk associated with liquefied ammonia requires careful engineering and operational protocols. This project addresses the need for robust tools and procedures to manage those risks effectively.
ClassNK’s Role and Commitment to Alternative Fuels
As part of the project, ClassNK will oversee the investigation into SCC mechanisms caused by liquid ammonia, examine the condition and usage of ammonia-fueled marine equipment, and lead long-term testing. The insights gained will be integrated into future ClassNK guidelines and shared with the maritime industry. This effort aligns with the organization’s broader mission to assist clients in their transition to zero-emission operations through services like the “ClassNK Transition Support Services.” By participating in initiatives such as this, ClassNK reaffirms its commitment to advancing alternative fuels and promoting a decarbonized future.
Did you subscribe to our Daily newsletter?
It’s Free! Click here to Subscribe!
Source: ClassNK
