Advanced UNet for high-resolution semantic segmentation of low-alloy steel corrosion evaluation and prediction
摘要
A novel image-based corrosion assessment method for low-alloy steels by integrating deep learning with quantitative metallography is proposed. The critical challenges of in situ corrosion monitoring in marine environments are addressed by introducing three key innovations: (1) a five-stage corrosion classification scheme based on combined macro- and micro-scale morphological analysis; (2) a high-quality annotated dataset (LASCD-UHD-2025) containing 1000 ultra-high-resolution images (5472 pixel × 3648 pixel) of Q420 and Q420RE steels under 3.5 wt.% NaCl immersion; and (3) an advanced UNet architecture enhanced with global attention module, triplet attention mechanism, and a Canny edge-weighted loss function. The advanced UNet achieves 53% mean intersection over union and 56% mean average precision, which is about 18% and 15% higher than the baseline UNet. Validation via gravimetric corrosion test, electrochemical characterization, and microscopic analysis confirms the reliability of the segmentation results. Using this method, we quantify that rare earth-alloyed Q420RE steel exhibits an approximately 14% slower corrosion progression compared to conventional Q420 steel during the initial corrosion stage. This integrated method enables automated, non-destructive corrosion monitoring, and offers broad potential for in situ real-time corrosion monitoring of materials used in marine environment.