What Does Re-rust Mean?
Re-rust refers to the occurrence whereby hydrated oxides reoccur on a metal's surface in a location that had previously been treated and declared corrosion-free. Rust is an undesirable product that is formed by iron as it oxidizes, and is a physical identifier of the presence of corrosion.
Corrosionpedia Explains Re-rust
Rust formation is due to oxidation. This occurs when there is an electrolyte and an electrical potential difference between two materials. The rusting reaction involves oxygen atoms from the atmosphere or electrolyte being transferred through the electrolytic cell to react with the iron to form iron oxide.
The following are some actions that may be taken to prevent re-rust formation:
- Removal of the electrolyte from an application, surface or system
- Use of a protective coating on the metal's surface
- Removal of oxygen from an application's atmosphere
- Use of a sacrificial anode to absorb oxygen molecules
- Alloying of the base metal with chromium or nickel