Recent research into the fretting wear damage mechanism of Inconel 690 alloy tubes, pivotal components in nuclear power plant steam generators, has revealed critical insights that could significantly influence the construction and maintenance of nuclear facilities. Conducted by CHEN Runluo from the School of Mechanical Engineering at Zhejiang University of Technology, this study highlights the challenges posed by high-temperature and high-pressure environments, which are characteristic of nuclear operations.
The steam generator’s heat transfer tubes are subjected to complex stresses, primarily due to flow-induced vibrations and periodic loads. These factors can lead to fretting wear and fatigue, ultimately resulting in cracks or catastrophic failures. “Understanding the wear failure mechanisms is essential for enhancing the reliability and safety of nuclear power systems,” CHEN stated, emphasizing the urgency of addressing these wear issues.
The research utilized advanced fretting wear testing machines to simulate real-world conditions, examining how different normal loads and displacement amplitudes affect the wear of Inconel 690 alloy tubes and 403SS anti-vibration bars. Notably, the study found that at room temperature, increased normal loads lead to debris accumulation and delamination on the worn surfaces, alongside intensified oxidation. “The primary mechanisms contributing to wear include friction oxidation, abrasive wear, and delamination,” CHEN explained.
In high-temperature air conditions, the findings were even more pronounced. The peak friction force and depth of worn scars increased, while the width of the scars decreased, indicating a more severe wear process. The research revealed that plastic flow becomes significant under these conditions, further complicating the wear mechanisms at play. “This deeper understanding of wear behavior under thermal stress can guide future material selection and design improvements in nuclear applications,” CHEN noted.
The implications of this research extend beyond academic interest; they are crucial for the construction sector, particularly for companies involved in the design and maintenance of nuclear infrastructure. As the industry moves towards more resilient and efficient energy solutions, the insights gained from this study could lead to innovations in material technology and engineering practices. Enhanced understanding of wear mechanisms may facilitate the development of more durable components, ultimately reducing maintenance costs and downtime for nuclear facilities.
This important work was published in ‘Cailiao gongcheng’, translated as ‘Materials Engineering’, and underscores a growing need for rigorous research in materials science to support the evolving demands of the energy sector. For further details on CHEN Runluo’s research, visit Zhejiang University of Technology.
