Visualization of Water in Corroded Region of Painted Steels at a Compact Neutron Source

Modern civil structures such as bridges are required to have a low life-cycle cost and a long life. Since the corrosion damage of steel cannot be avoided in practical environments,1) effective countermeasures against corrosion are strongly required. Paint coatings are the most widely used method for preventing the corrosion of general structures.2) On the other hand, it is a challenging task to reduce the life-cycle costs of structures including the initial cost and the maintenance cost for repainting and there are continuous needs of constructions. However there are always budgetary constraints. In the case of painted steel, water may penetrate under the coating film over time. When defects are formed in the film, the water can penetrate, induce under-film corrosion, and eventually cause blisters on the coating film. Painted steel structures must therefore be repainted periodically, which increases their maintenance cost. Attempts are being made to prolong the life of paint coatings which include the development of heavy-duty coatings and/or alloy steels.3) Until now, these have been three major approaches to research and development to improve the corrosion resistance of paint coatings: (1) Adding suitable alloying elements to the Visualization of Water in Corroded Region of Painted Steels at a Compact Neutron Source