galvanized iron
Noun
Meaning
iron that is coated with zinc to protect it from rust
Source: WordNetHypernyms
Examples
For potable water use, galvanized iron piping was commonplace in the United States from the late 1800s until around 1960.
Marine and salty environments also lower the lifetime of galvanized iron because the high electrical conductivity of sea water increases the rate of corrosion primarily through converting the solid zinc to soluble zinc chloride which simply washes away.