Role of High‐Temperature Oxidation in Exhaust Valve Failure of Diesel Locomotive Engines: An Entropy‐Based Failure Mode Analysis Approach

Failure analysis is an essential tool for understanding the root causes of component degradation, especially in systems operating under severe thermal and mechanical conditions. Exhaust valves in diesel locomotive engines are continuously exposed to high‐temperature gases, making them vulnerable to oxidation, corrosion, and other damage mechanisms. In this study, an attempt has been made to examine the influence of high‐temperature oxidation on the failure behavior of exhaust valves used in high horse power diesel engines. A structured analysis was carried out using failure mode and effects analysis to identify the possible failure modes associated with valve operation. To improve the reliability of the prioritization process, the R‐method along with entropy‐based gray relational analysis was applied. This combined approach allows a more balanced evaluation by incorporating both data‐driven and analytical weighting techniques. The findings suggest that the formation of oxide scale on the valve stem and seating surfaces plays a significant role in initiating failure. Continuous exposure to elevated temperatures leads to scale accumulation, which in turn causes thermal stresses, surface damage, and gradual loss of material strength. Moreover, erosion at the valve face accelerates the oxidation process by exposing fresh surfaces, thereby intensifying degradation. The study also highlights that inadequate material resistance to high‐temperature environments further increases the risk of failure. Overall, the results underline the importance of considering oxidation behavior in the design and maintenance of exhaust valves. The approach adopted in this work can be useful for improving component reliability and guiding future research on high‐temperature material performance.