The five major elements for routine analysis of steel chemical composition are carbon, sulfur, silicon, phosphorus, and manganese. The introduction is as follows:

1. Carbon is one of the main components of steel and directly affects its performance. Carbon is the main symbol that distinguishes iron from steel, determines the grade and grade of steel, and plays a decisive role in the performance of steel. Carbon can serve as a hardening and strengthening agent in steel;

2. Silicon is intentionally added due to the introduction or deoxidation of raw ore and special needs. During the steelmaking process, silicon is added as a reducing and deoxidizing agent, which can significantly improve the elastic limit, yield point, and tensile strength of steel;

3. A small amount of manganese is introduced from the raw ore and added as a desulfurization and deoxygenation agent during the steel smelting process, which gives the steel sufficient toughness, high strength and hardness, improves the hardenability of the steel, and improves the hot working performance of the steel;

4. Phosphorus is introduced from raw materials. In general, phosphorus is a harmful element in steel, which increases the cold brittleness of the steel, deteriorates the welding performance, reduces plasticity, and deteriorates the cold bending performance;

5. Sulfur is mainly introduced into steel through coke or raw ore, and it is usually a harmful element that causes thermal brittleness, reduces the ductility and toughness of the steel, causes cracks during forging and rolling, and is also detrimental to welding performance, reducing corrosion resistance.