Iron is oxidized under wet conditions to produce ferroferric oxide, that is, rust, which can be replaced by acid. But vinegar is useless, and the acid that replaces iron must be strong acid, such as hydrochloric acid or dilute sulfuric acid.

Putting rusty iron products into hydrochloric acid can achieve the effect of rust removal and wash away the rust on the surface of iron products. After the rust removal of iron parts is completed, it is best to carry out one-step rust prevention treatment, that is, soak the iron parts in rust inhibitor for one or two minutes, so that there is no need to worry about the rust of iron parts here.

Extended data:

Rusting is a chemical reaction, which is essentially an oxidation reaction of metals. The most common rust phenomenon is that iron products are exposed to air for a long time and react with oxygen, or are corroded by oxygen in water to become oxides.

Rusting is a chemical reaction. Iron will rust if left for a long time. Iron rusts easily, not only because of its active chemical properties, but also because of external conditions. Moisture is one of the substances that make iron rust easily.

However, only water will not rust iron. Only oxygen in the air is dissolved in water, and in an environment with water, oxygen will react with iron to generate iron oxide. This is rust. Rust is a reddish-brown substance, which is not as hard as iron and easy to fall off. When a piece of iron is completely rusted, its volume can expand by 8 times.

References:

Baidu encyclopedia-rust