Definition - What does White Rust mean?
White rust is a type of zinc corrosion that is highly complex in nature, presenting as hydrated zinc carbonate or zinc hydroxide. White rust commonly develops in environments with high moisture content and zinc reactivity.
Corrosionpedia explains White Rust
White rust often affects materials made from steel. It can be prevented primarily by storing or installing the material in a dry environment with a temperature above the dew point. Regular inspections, protective coverings and unstacking are also beneficial.