What is rust bloom?

Rust bloom refers specifically to the surface discoloration that occurs on steel when it oxidizes. This phenomenon is characterized by the reddish or brownish patches that develop on the surface of steel materials, which is primarily caused by the reaction of iron with moisture and oxygen in the environment.

While corrosion of steel due to moisture is a related concept, it encompasses a broader range of chemical reactions that affect not just the color but also the structural integrity of the material. Metal polishing, on the other hand, is a process aimed at achieving a smooth surface through abrasion and does not involve discoloration. Lastly, oxidation of iron at low temperatures is a specific type of chemical reaction, but rust bloom can occur at various temperatures and is more specifically tied to the visible effects of rust itself. Thus, surface discoloration on steel captures the essential definition of rust bloom effectively.