关键词: 点蚀, 随机过程, 港口机械, 非齐次泊松过程, 伽马过程, Monte Carlo模拟

Abstract: Pitting corrosion was one of the most serious modes of localized corrosion which caused port machinery to decay. The process of pitting initiation and propagation was subject to the interaction of environmental, metallurgical and stress factors. It was an uncertain nature from which no explicit relationship could be drawn by any deterministic models. Firstly, the physical interpretation of the pitting formation was discussed. On the basis of stochastic theory, combining experimental data, a modeling method was proposed with Non-Homogeneous Poisson process (NHPP) for pitting initiation and stationary gamma process for pitting propagation. A stochastic degradation model was constructed to effectively depict the causes of bringing pitting corrosion. Finally, the stochastic degradation model was simulated and tested. Results indicated that the presented model was valid in analyzing the pitting initiation and propagation according to different combinations of modeling parameters. It was significance to the life prediction and development of relevant maintenance plans of port machinery.

Key words: pitting corrosion, stochastic process, port machinery, non-homogeneous Poisson process, Gamma process, Monte Carlo simulation