Performance and Applications of Grade B (L245) Line Pipe Steel

Grade B (L245) is one of the commonly used low–medium strength line pipe steel grades under the API 5L standard. It is designed to meet the needs of medium-pressure oil and gas transportation, offering a balance between strength, toughness, and weldability. This steel grade is widely used in welded or seamless steel pipe manufacturing for pipeline systems.

In terms of characteristics, L245 provides good weldability, formability, and pressure resistance. With a yield strength of around 245 MPa and tensile strength above 415 MPa, the material offers excellent ductility and can undergo cold bending, welding, and coating processes easily. Its mechanical stability makes it suitable for various engineering environments.

The chemical composition of Grade B steel is based on low-carbon steel, typically containing a maximum carbon content of 0.26% along with controlled amounts of manganese, phosphorus, and sulfur. To ensure good weldability, P and S levels are kept very low. In some production routes, microalloying elements such as Nb, V, and Ti may be added to refine the grain structure and optimize mechanical properties.

Grade B (L245) is commonly supplied in hot-rolled, controlled-rolled, normalized, or normalized and tempered delivery states, ensuring the product meets different project requirements. It is available as welded pipes, seamless pipes, and spiral welded pipes.

Grade B is mostly used for onshore oil transmission pipelines, natural gas distribution systems, city gas networks, and water supply pipelines. Its reliable toughness and moderate strength also make it suitable for structural components requiring good ductility.