Test and Simulation Analysis on the Corrosion Evolution over Time of H-shaped Steel Components
H-shaped steel components are ubiquitous in steel structures, yet corrosion research has largely remained confined to two-dimensional flat plates, leaving the spatial-geometric effects on three-dimensional sections poorly quantified. This study addresses that gap through neutral salt spray (NSS) corrosion experiments on H-shaped steel specimens positioned at 0°, 45°, and 90° over corrosion cycles extending to 60 days, coupled with a three-dimensional cellular automata (3D-CA) model of the corrosion evolution. The spatial placement angle exerts a decisive influence on corrosion distribution. At 0° and 45°, the upper flange corrodes more severely than the web, while the lower flange remains least affected; the 45° specimen, however, exhibits accelerated attack because its inclined geometry prevents formation of a protective NaCl electrolyte film on the flanges. At 60 days, the 45° specimen's F1 surface shows average rust layer thickness and average pit depth exceeding those of the 0° specimen by 45.79% and 54.78%, respectively. At 90°, the W1 surface is most severely corroded, followed by the flanges, with W2 least affected. The 3D-CA model reproduces the time-dependent corrosion morphology, yielding pit depth distributions consistent with a Weibull function and agreeing with experimental pit morphology and depth within 5% error. The model is validated as a reliable predictor of spatially heterogeneous corrosion evolution in H-shaped steel, though it currently omits coupled stress and external loading effects.