L245 is a core grade of pipeline steel (carbon steel for oil and gas transportation). It belongs to low-alloy high-strength steel and conforms to the national standard GB/T 9711-2017 "Steel pipes for pipeline transportation systems in the oil and gas industry". It is mainly used to manufacture pipelines (including straight pipes, bends, and fittings) for transporting media such as oil, natural gas, and water. It is a key steel product in the energy transportation field.
L245 Core Basic Information
1. Grade Meaning
"L": Represents "Line pipe", clearly indicating its use as a transportation pipeline;
"245": Refers to the steel's yield strength ≥ 245MPa (core mechanical indicator), corresponding to a tensile strength of 415-565MPa and an elongation ≥ 22%, belonging to the category of medium and low pressure pipeline steel.
2. Material Characteristics
Composition: Based on carbon steel, containing small amounts of alloying elements such as manganese (Mn) and silicon (Si), with low impurity content (S≤0.030%, P≤0.030%), ensuring weldability and toughness;
Key Performance: Good weldability (suitable for on-site welding and laying), low-temperature toughness (adaptable to -20℃ to ambient temperature conditions), corrosion resistance (suitable for soil, underground/underwater environments);
Standards: Domestic GB/T 9711-2017, internationally equivalent to API 5L Gr.B (similar performance, commonly used for multinational project docking).
3. Common Specifications:
Pipe Diameter: φ21.3mm~φ1620mm (Seamless pipe / Straight seam submerged arc welded pipe);
Wall Thickness: 2.11mm~40mm (Adjusted according to conveying pressure and distance; 6-12mm is commonly used in low and medium pressure applications);
Length: Standard 6m/12m/piece, custom lengths available (e.g., 10m, 15m);
Delivery Condition: Hot-rolled (HR), normalized (N); special corrosion protection treatments available (3PE anti-corrosion, epoxy coal tar coating).
Applications
L245 pipeline steel is widely used in the construction of long-distance pipelines for oil and natural gas transportation, and is a key material in the energy transmission field. Typical applications include:
Oil/Natural Gas Transportation: Long-distance oil and gas trunk pipelines, urban gas branch pipelines, and internal oilfield gathering and transportation pipelines (medium-low pressure conditions, pressure ≤4MPa). For example, national strategic projects such as the West-East Gas Pipeline III and the China-Russia East Route Gas Pipeline extensively use L245 pipeline steel, with approximately 35% of the material used in the West-East Gas Pipeline III.
Water Supply and Drainage Engineering: Urban tap water main pipes, sewage treatment plant pipelines, and industrial circulating water pipelines (resistant to soil corrosion, requiring minimal maintenance).
Chemical Industry: Pipelines for transporting low-corrosion media (such as cooling water and common solvents), and pipes for chemical equipment (such as reactor heat exchanger pipes and distillation tower support pipes).
Municipal Engineering: Pipeline sleeves in urban underground integrated pipe corridors, and heating networks (non-high-temperature scenarios, temperature ≤100℃).
Infrastructure projects: water supply and drainage pipelines for bridges and docks, and energy transmission branch pipes for airports/industrial parks.
