(1) Covering the surface of iron products with a protective layer is a common and important method to prevent iron products from rusting. According to the composition of the protective layer, it can be divided into the following types:

a. Coat the surface of iron products with mineral oil, paint or fired enamel, spray plastic, etc. For example: carriages, buckets, etc. are often painted with paint; machines are often coated with mineral oil, etc.

b. A layer of metal that is not prone to rust, such as zinc, tin, chromium, nickel, etc., is plated on the steel surface using electroplating, hot plating or other methods. These metal surfaces can form a dense oxide film to prevent iron products from rusting due to contact with water, air and other substances.

c. Use chemical methods to form a dense and stable oxide film on the surface of iron products to prevent iron products from rusting.

(2) Form an alloy to change the internal structure of iron. For example, adding chromium, nickel and other metals to ordinary steel to make stainless steel greatly increases the rust resistance of steel products.

(3) Keeping the surface of iron products clean and dry is also a good way to prevent iron products from rusting.