What Are The Control Requirements For The Chemical Composition Of The Line Pipe?

PSL2 has strict limits on chemical composition. With X46 PSL2 as an example, carbon equivalent (CE) is subject to mandatory upper limit requirements. Impurities such as phosphorus and sulfur are strictly controlled to improve toughness and HIC/SSC resistance. Microalloy elements such as niobium, vanadium and titanium are added to refine grains. Different steel grades and wall thicknesses have different carbon equivalent limits, and the larger the wall thickness, the more strict the requirement.