Rational determination of real-time corrosion rates based on ultrasonic wall thickness loss data

Abstract

Real-time corrosion rate measurement is crucial to understanding corrosion kinetics and proposing effective corrosion control and prevention strategies. In situ ultrasonic testing has emerged as a promising approach for monitoring corrosion-induced wall thickness losses. In this work, the Generalized Likelihood Ratio (GLR) algorithm is adopted to process the wall thickness measurements acquired by in situ ultrasonic testing, so as to achieve rational and automated determination of real-time corrosion rates. During a corrosion process, the GLR algorithm will continuously gauge the probability of occurrence of a change in corrosion rate; once it deems that a change has occurred, the new corrosion rate will be evaluated based on the data points bounded by the present and the preceding change in corrosion rate. The proposed corrosion rate monitoring technique was applied to both controlled and natural corrosion processes, demonstrating high measurement accuracy and stability as well as robustness in complex corrosion systems.