The five major elements that are conventionally analyzed in the chemical composition of steel are carbon, manganese, sulfur, phosphorus, and silicon. Carbon is the most important element in steel as it determines its strength and hardness. Manganese is added to increase the toughness and hardenability of steel. Sulfur and phosphorus are considered impurities and are usually kept to a minimum as they can cause brittleness and reduce the ductility of steel. Silicon is added to improve the strength and resistance to oxidation of steel.

Analyzing the chemical composition of steel is crucial as it determines its suitability for various applications. For example, low carbon steel is used in applications that require high ductility and toughness, while high carbon steel is used in applications that require high strength and hardness. Similarly, the addition of other elements such as chromium, nickel, and molybdenum can further enhance the properties of steel for specific applications.

Overall, understanding the chemical composition of steel is essential for ensuring its quality and suitability for various industrial applications.