How carbon steel alloys work is based primarily on their chemical composition and physical properties, especially how the carbon and other alloying elements in their composition affect the material's performance.
Basic Properties of Carbon Steel
Carbon steel is an iron alloy that is primarily composed of iron and carbon, with small amounts of silicon, manganese, sulfur, phosphorus, and other elements. Carbon steel tends to rust in humid environments because the iron on the metal surface reacts chemically with moisture and oxygen in the air to form iron oxide (rust). To prevent carbon steel from rusting, surface treatments such as galvanizing, tinning, or painting are usually required.

