Rusting iron - ugly, or a burst of colour?
Channel: bhadeshia123
Date: 2020-01-12

Rust on iron is usually regarded as an anathema. Here I show the practical utility of rust, first to deter thieves, and then to form an elegant patina that protects the steel. This kind of weathering steel has a lovely colour that blends with both forest environments and modern architecture. The steel requires no painting or maintenance.

Weathering steels contain various combinations of small concentrations of copper, chromium and phosphorus. This makes the rust (which is not a single compound) more compact and hence less permeable to the environment, and more adherent to the steel. Normal rust forms in the fluid ahead of the steel so does not attach well to the steel.

https://www.phase-trans.msm.cam.ac.uk