uncorroded
/ˌʌnˈkɒrəd/Definitions
1. adjective
not affected by corrosion; not worn away or damaged by chemical reaction, especially with water or air.
“The uncorroded metal was discovered in the old shipwreck.”
2. adverb
in a state of not being affected by corrosion.
“The engineer inspected the uncorroded pipes carefully.”