What is high quality structural steel

High quality structural steel must ensure chemical composition and mechanical properties at the same time. The grade is the ten thousand fraction (ωс**10000) that uses two digits to indicate the mass fraction of average carbon in the steel. For example, 45 steel means that the average carbon mass fraction in steel is 0.45%, and 08 steel means that the average carbon mass fraction in steel is 0.08%.

High quality structural steel is mainly used to manufacture machine parts. Generally, heat treatment is required to improve mechanical properties. According to the different carbon mass fraction, there are different uses.

08, 08F, 10, 10F steel have high plasticity and toughness, excellent cold forming performance and welding performance, which can often be cold rolled into thin plates and always are used to make cold stamping parts on instrument housings, cars and tractors, such as car bodies, tractors cab, etc.

15, 20, 25 steel are used to make carburized parts with small size, lighter load, wear-resistant surface, and low core strength requirements, such as piston pins, prototypes, etc.

30, 35, 40, 45, 50 steel have good comprehensive mechanical properties after heat treatment (quenching + high temperature tempering), that is, they have higher strength, higher plasticity and toughness, and are used to make shaft parts, such as 40 , 45 steel is often used in the manufacture of crankshafts, connecting rods, general machine tool spindles, machine tool gears and other shaft parts with little force on automobiles and tractors.

55, 60, 65 steel have a high elastic limit after heat treatment, and is often used to make springs with low load and small size , such as pressure regulating and speed regulating springs, plunger spring, cold coil spring, etc.​

Pre: What are the chemical performance indicators of steel?

Next: Introduction of round steel tube