Steam Erosion Failure on ASTM A210 Grade A1 Waterwall Tube of Subcritical Boiler

This failure analysis investigates tube failures in waterwall components of boilers, crucial for converting water into superheated steam. The study aims to distinguish primary leaks from secondary damage mechanisms, offering insights for power plant OEM safety references. Utilizing visual inspection and validated data collection methods, macrography analysis reveals wall thinning from steam erosion, reducing thickness to a critical 0.085 mm, far below the required 2.8 mm. SEM testing displays dimple rupture patterns, with metallography and hardness tests indicating no microstructural degradation. Chemical composition aligns with ASTM A210 Grade A1. Conclusively, the analysis attributes tube failures to steam erosion, classifying it as a secondary damage mechanism. The results guide the development of mitigation strategies, emphasizing immediate shutdown actions to ensure boiler safety and efficiency. This comprehensive study aids in preventing future tube failures, contributing to the reliability of boiler operations in power plants.