Linking Accelerated Corrosion Responses to Field Marine Atmospheric Corrosion of Low‐Alloy Steels Through Modelling and Rust‐Layer Characterization

ABSTRACT Accelerated corrosion tests are widely used to evaluate low‐alloy steels, but whether short‐term laboratory responses can represent long‐term marine atmospheric corrosion remains uncertain. In this study, ten low‐alloy steels were tested under nine cyclic corrosion test (CCT) conditions designed by an L9(3 3 ) orthogonal array and linked to field exposure data from Wanning and Qionghai. Corrosion responses were encoded as a Corrosion Resistance Fingerprint (CRF) and combined with alloy composition and environmental descriptors in a two‐stage Extreme Gradient Boosting (XGBoost) model. The CRF‐augmented model achieved an R 2 of 0.907 on 70 external validation data points, compared with 0.622 for a conventional power‐law equivalence method. Paired rust‐layer characterization showed that the alloy‐dependent differences in surface damage and rust‐layer stability were preserved under indoor and outdoor exposure conditions. These results support the laboratory‐to‐field transferability of accelerated corrosion responses.