Steel

The most produced type of steel is carbon steel. It is made of carbon and iron and accounts for about 90% of the world's steel production.

An excerpt from the article 14 facts about steel

It can have aditional elements but in small quantities. Carbon steel is used in the construction of buildings, bridges, railroad tracks, automobile parts, and pipes for the oil industry. Since it is susceptible to corrosion, it shouldn't be used with water and in humid conditions. To protect it from rusting, it is coated with protective coatings such as paints.