API 5L is a line pipe standard developed by the American Petroleum Institute.
The steel grades in API 5L mainly include: A, B, X42, X46, X52, X56, X60, X65, X70, X80, X90, X100, X120, etc.
His naming method is basically named after the capital letter X plus the minimum yield strength of the material.
Of course, the difference between different steel grades is not only the difference in yield strength, they are very different in manufacturing process, chemical composition, physical properties, inspection methods and so on.
When API 5L was formulated, it considered that there were two basic levels of standard technical requirements for line pipes, so it established two technical requirements for product specification levels: PSL1 and PSL2. PSL1 provides general line pipe quality level requirements. PSL2 includes mandatory requirements for added chemical composition, notch toughness, strength properties and supplemental NDE.

Pipeline steel refers to a type of steel with special requirements for pipelines used to transport oil and natural gas. According to the difference in thickness and subsequent formation, it can be produced by hot tandem rolling mills, steckel mills or plate mills. Spiral welding or UOE straight seam welding to form large diameter steel pipes.

Pipeline steel application

Pipeline steel product forms include seamless steel pipes and welded steel pipes, which can be divided into three categories: alpine, high-sulfur areas and seabed laying.

Pipeline Steel Properties

From the comprehensive evaluation of the development trend of oil and gas pipelines, pipeline laying conditions, main failure modes and failure reasons, pipeline steel has good mechanical properties (thick wall, high strength, high toughness, wear resistance), and also has large diameter and weldability. , Cold and low temperature resistance, corrosion resistance (CO2), resistance to seawater and HIC, SSCC performance, etc.