I don't have a source, but as an engineer working for the US Navy, we are frequently told that the Navy spends an enormous amount of money on corrosion control.

I don't have a source, but as an engineer working for the US Navy, we are frequently told that the Navy spends an enormous amount of money on corrosion control. Like, in the billions to tens of billions of dollars per year. As a consequence, corrosion control is a significant fraction of the Navy's R&D budget. https://www.gao.gov/assets/650/647926.txt https://www.gao.gov/assets/650/647926.txt https://www.onr.navy.mil/en/Science-Technology/Departments/Code-33/All-Programs/333-sea-platforms-weapons/Corrosion-Control https://www.onr.navy.mil/en/Science-Technology/Departments/C...