High quality structural steel

This kind of steel must ensure both chemical composition and mechanical properties. Its grade is a two-digit number representing the mass fraction of the average carbon in the steel (w) ×10000). For example, 45 steel indicates that the average mass fraction of carbon in steel is 0.45%; 08 steel indicates that the average mass fraction of carbon in steel is 0.08%, and high-quality carbon structural steel is mainly used to manufacture machine parts. It is generally heat treated to improve mechanical properties. Depending on the mass fraction of carbon, it has different uses. 08, 08F, 10, 10F steel, high plasticity, toughness, with excellent cold forming performance and welding performance, often cold rolled into sheet, used to make instrument shell, car and tractor cold stamping parts, such as car body, tractor cab, etc.; 15, 20, 25 steel is used to make carburized parts with small size, light load, wear-resistant surface requirements and low core strength requirements, such as piston pins, templates, etc. 30, 35, 40, 45, 50 steel after heat treatment (quenching + high temperature tempering) has good comprehensive mechanical properties, that is, has high strength and high plasticity, toughness, for the production of shaft parts, such as 40, 45 steel is often used in the manufacture of automobiles, tractors crankshaft, connecting rod, general machine tool spindle, machine tool gear and other shaft parts with little force; 55, 60, 65 steel has a high elastic limit after heat treatment (quenching + medium temperature tempering), and is often used to make springs with small load and small size (cross section size less than 12 ~ 15mm), such as pressure regulation and speed regulation springs, plunger springs, cold coil springs, etc.