An experiment to reduce corrosivity in submarine sonar domes by nitrogen injection

The Applied Physics Laboratory at the University of Washington (APL-UW) and the Naval Sea Systems Command (NAVSEA) undertook a long-term study on reducing corrosion in submarine sonar domes. For several years APL-UW, under the auspices of NAVSEA, has inspected dome structures and recommended improvements in their design, materials, and maintenance. Classical corrosion control on submarines has emphasized exclusively materials selection and processing, protective coatings, and planned maintenance. Since about 1990, we have added the idea of understanding what factors change the corrosivity in sonar domes and how to reduce that corrosivity. Tests have been conducted to determine the corrosivity rates of sonar-dome materials, instrumentation has been devised to monitor dome-water corrosivity in situ, and follow-on tests have been conducted to determine the feasibility of injecting nitrogen into the dome water to reduce the corrosion rate