Integrating Mass Transfer, Electrochemical Kinetics and Industry Standards into a Stochastic Risk-Based Corrosion Framework

The integrity of industrial fluid systems is fundamentally governed by the complex interplay between electrochemical reactions and hydrodynamic transport phenomena. Mass transfer-controlled corrosion remains one of the most significant challenges in asset integrity management, particularly within the oil, gas, and petrochemical sectors, where turbulent flow regimes are ubiquitous. This review provides an extensive analysis of the mathematical foundations of diffusion-limited corrosion, focusing on the role of the Nernst diffusion layer and the application of dimensionless groups-specifically the Sherwood, Reynolds, and Schmidt numbers in predicting material degradation. A central contribution of this work is the synthesis of technical requirements from API RP ۵۷۱/۵۸۱, NACE/AMPP standards, and ASME Section VIII/FFS-۱, establishing a unified roadmap for calculating corrosion rates in complex geometries. Beyond deterministic modeling, this work introduces an advanced stochastic reliability framework to bridge the gap between transport phenomena and Risk-Based Inspection (RBI) protocols. By treating the mass transfer coefficient as a random variable and employing a Log-Normal distribution within a limit state function, the model accounts for turbulence-induced variance in wall thinning. This approach allows for a more accurate determination of the Probability of Failure (POF) and Remaining Useful Life (RUL), providing engineers with a robust tool for optimizing inspection intervals in high-risk, high-velocity assets. The integrated framework presented herein facilitates a transition from traditional reactive maintenance to a proactive, physics-informed integrity strategy.

کلیدواژه ها:

Mass Transfer ، Corrosion Kinetics ، CO۲ Corrosion ، Pitting Corrosion ، RBI