Corrosion protection of boilers, steam and condensate systems, which are important in water use facilities, is explained in an easy-to-understand manner for beginners. Describes the causes of corrosion in boilers and steam-using installations and explains the main anti-corrosion technologies. Chemicals to be applied at the same time should be described so that the reaction is as easy to understand as possible.

A soft sensor is developed to predict high-temperature corrosion rates of boiler tubes from plant operation data. A machine learning model of the soft sensor is formulated in combination of multiple linear regression analysis and principle component analysis. Model parameters of the prediction formula with plant operation data as variables are optimized by measured data of corrosion rate using an electrochemical probe, and the generalized performance is evaluated with cross-validation.

To monitor the corrosion behavior of Aluminum in wet and dry cyclic condition, ICM sensor consisting of two spiral-shaped electrodes was developed. The impedance of Aluminum was measured while repeating drying and wetting with NaCl which is deposited to the ICM sensor. The integrated value of the reciprocal of 1 Hz impedance obtained from the ICM sensor had a good correlation with the amount of corrosion obtained from the RCM sensor. A simulated test in which mud and snow-melting agents were mixed showed uniform wettability and sustained corrosion.

This study examined the relationship between the microstructure of the base metal and its corrosion behavior using abrasive water-jet treatment （AWT）. The changes in the surface configuration and microstructural features of carbon steel obtained at different standoff distances from AWT were compared to those of blast treatment. The surface characteristics of the specimens were assessed for their roughness and microstructure. The relationship between roughness and corrosion behavior was the opposite result of conventional literature and showed that factors other than roughness among surface properties have a greater influence on the corrosion resistance for specimens treated in this study. The experimental results showed that the smaller the standoff distance, the changes in microstructures induced from the increased plastic deformation layers during the AWT became apparent. As the energy arriving at the substrate during the AWT increased, we observed the increased surface hardening and the reduced grain size on the plastic deformation sections, which resulted in improved corrosion resistance. Therefore, it was demonstrated that the surface cleaning of AWT has a positive effect on the corrosion properties of the base materials, which maintained their lifespan.