Types of structural steel and their applications

Structural steel is a type of steel that meets specific strength and formability grades. It is widely used in civil engineering such as buildings, bridges, railways, highways, ports, and mines, as well as in machinery manufacturing, automobile manufacturing, and shipbuilding. There are many types of structural steel, which can be divided into the following categories according to their composition and performance:

1. Ordinary carbon structural steel: such as Q235, Q235B, Q235C, Q235D, Q235E, etc., have good comprehensive mechanical properties and are widely used in the production of structural parts of construction projects.
2. Low-alloy high-strength structural steel (referred to as low-alloy steel): such as Q345, Q390, etc., this type of steel is based on ordinary carbon structural steel. A certain amount of alloy elements are added to improve the strength and toughness of the steel, which is suitable for the construction of large-span and high-rise structures.
3. High-strength structural steel: such as Q420, Q460, etc., have higher strength and excellent low-temperature impact performance, suitable for low-temperature environments and the construction of important structures.
4. Structural steel for bridges: such as HG70, HG70E, etc., with high strength and good toughness, specially used for the construction of bridge structures.
5. Structural steel for engineering machinery: such as 42CrMo, 40Cr, 35CrMo, 20CrMnTi, etc., with high strength and wear resistance, suitable for structural parts of engineering machinery and heavy-duty vehicles.
6. Spring steel: mainly used to manufacture springs, gears and other parts that require high elasticity and wear resistance.
7. Weathering structural steel: has excellent atmospheric corrosion resistance and is suitable for structural parts exposed outdoors for a long time.
8. Easy-to-cut structural steel: easy to cut and suitable for mechanical parts that require high-efficiency processing.
9. Non-quenched and tempered mechanical structural steel: through specific smelting and rolling processes, good comprehensive mechanical properties are obtained, and no further quenching and tempering treatment is required for use.

Structural steel has a wide range of uses, mainly including the following aspects:

1. Civil engineering: used for the production of structural parts such as buildings, bridges, roads, tunnels, such as beams, columns, plates, frames, etc.
2. Machinery manufacturing: used to manufacture various mechanical parts and components, such as gears, bearings, shafts, etc.
3. Automobile manufacturing: used for the manufacture of key components such as automobile bodies, chassis, engines, etc.
4. Shipbuilding: used for the manufacture of structural parts such as ship hulls, decks, cabins, etc.
5. Energy and chemical industry: used for the manufacture of pressure vessels, pipelines, storage tanks and other equipment that need to withstand high pressure and corrosive environments.
6. Other fields: such as mining machinery, agricultural machinery, aerospace and other fields are also widely used.
    

In general, structural steel has many types and different properties, but all have high strength and toughness, can resist various stresses, and ensure the safety and stability of the project.