Corrosion detection for steel with soft coating using in-line fiber Bragg grating sensor

Soft coatings are popularly applied in industry to prevent corrosion for structural steel. However, coatings cannot fully prevent corrosion from happening. In this paper, an inline corrosion monitoring system for steel was extended to steel with soft coating based on fiber Bragg grating sensors (FBGs). Experimental results show that an increase in central wavelength of FBGs can be detected if corrosion occurs under soft coatings. A positive relationship between the status of corrosion and the increase in central wavelength was also observed. This study revealed the potential of FBGs to serve as corrosion assessment technique for steel protected with soft coatings.