1. Low alloy high strength structural steel
Low alloy high strength structural steel is mainly used for buildings, bridges, ships, vehicles, pressure vessels and other structures, the carbon content (smelting analysis) is generally not more than 0.20%, the total content of alloying elements is generally not more than 2.5%, the yield strength is not less than 295MPa, and has good impact toughness and weldability of low alloy steels.
2. Carbon structural steel
Carbon structural steel is widely used in buildings, bridges, ships, vehicles and other structures which must have a certain strength, and if necessary, require impact performance and welding performance.
3. Steel for building structure
Steel for building structure is mainly used in the construction of tall and important building structures. It is required to have high impact toughness, sufficient strength, good weldability, a certain yield ratio, and if necessary, the thickness direction performance.
4. Steel for bridges
Steel used to build railway and road bridges. It is required to have high strength and sufficient toughness, low notch sensitivity, good low temperature toughness, anti-aging sensitivity, fatigue resistance and weldability. The main steels used are low-alloy high-strength steels such as Q345q, Q370q, and Q420q.
5. Steel for hull
Steel with good welding and other properties, suitable for repairing ships and main structures of ship hulls. Ship steel requires higher strength, better toughness, blast resistance and deep water crush resistance.
6. Steel for pressure vessels
Steel used in the manufacture of pressure vessels for petrochemical, gas separation and gas storage and transportation equipment. Sufficient strength and toughness, good weldability and hot and cold workability are required. The commonly used steels are mainly low-alloy high strength steels and carbon steels.
7. Steel for low temperature
For the manufacture of pressure equipment and structures used below -20°C, steels with good low temperature toughness and weldability are required. Depending on the operating temperature, the main steels used are low-alloy high-strength steel, nickel steel and austenitic stainless steel.
8. Steel for boilers
Steel used to make superheaters, main steam pipes, water wall pipes and boiler drums. It is required to have good room temperature and high temperature mechanical properties, anti oxidation and alkaline corrosion resistance, sufficient durable strength and durable fracture plasticity. The main steels are pearlitic heat-resistant steel (chromium-molybdenum steel), austenitic heat-resistant steel (chromium-nickel steel), high-quality carbon steel (20 steel) and low-alloy high-strength steel.
9. Steel for pipeline
Steel for oil and natural gas long-distance transmission pipelines. Low-alloy high-strength steels with comprehensive properties such as high strength, high toughness, excellent workability, weldability and corrosion resistance are required.
10. Alloy structural steel
On the basis of carbon structural steel, appropriate alloying elements are added, and it is mainly used to manufacture steel for mechanical parts with large cross-sectional dimensions. It has suitable hardenability, higher strength, toughness and fatigue strength after corresponding heat treatment, and lower brittle transition temperature. This type of steel mainly includes quenched and tempered steel, case hardened steel and cold plastic formed steel.
11. Weathering steel (atmoSPHEric corrosion resistant steel)
The steel with added copper, phosphorus, chromium, nickel and other elements to improve the resistance to atmospheric corrosion. This type of steel is divided into high weathering steel and weathering steel for welded structures.