Page 29 - Curriculum Visions Dynamic Book

(Above) Aluminium is self-protecting, which is one reason it can be used for food containers.
(Left, right, and below) Rust used to be the death of cars because the steel from which they were made was insufficiently protected from corrosion. Many layers of surface coating now help ensure that rust now only affects cars after many years. That is why cars now come with six or more years of bodywork rust warranty.
Unfortunately, the most commonly used metal – mild steel – does not develop a stable oxide coat. The corroded coating on mild steel is called rust.
Paints and lacquers
Vulnerable metals can be protected by covering them with a nonreacting material, for example, paint. Paint, lacquer, or some other similar unreactive surface material is fine if the surface is not subjected to high temperatures or hard wear. Paints are also unsuitable for surfaces used to prepare, store, or cook foods because flakes of paint could get into the food.
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