Chemical composition
Carbon (C) content: API 5L B pipe carbon content is generally between 0.15%-0.30%; while API 5L X46 pipe carbon content is usually between 0.18%-0.28%.
Manganese (Mn) content: API 5L B pipe manganese content is about 0.29%-1.20%; API 5L X46 pipe manganese content is generally 1.30%-1.40%, higher manganese content is one of the factors that X46 pipe strength is higher than B pipe.
Phosphorus (P) and sulfur (S) content: API 5L B pipe phosphorus content does not exceed 0.030%, sulfur content does not exceed 0.030%; under PSL1, X46 pipe phosphorus and sulfur content requirements are the same as B pipe, but under the more stringent PSL2 level, phosphorus content does not exceed 0.025%, sulfur content does not exceed 0.015%.
Other alloying elements: API 5L B pipe and API 5L X46 pipe are relatively basic carbon steels with relatively few alloying elements added. In addition to the main elements such as carbon and manganese, they may also contain a small amount of alloying elements such as niobium and vanadium.
Mechanical properties
Yield strength: The nominal yield strength of API 5L B pipe is 245MPa; the minimum yield strength of API 5L X46 pipe is 320MPa, which can withstand higher pressure than B pipe without permanent deformation.
Tensile strength: The tensile strength of API 5L B pipe is relatively low, about 414MPa; the tensile strength of API 5L X46 pipe is 434MPa, which is more advantageous when bearing tension and can ensure the safety of the pipeline under tensile stress.
Use / Application
API 5L B pipe: Usually used for pipelines that transport natural gas, water and oil. These pipelines are located in a relatively mild environment and the requirements for mechanical properties are not very strict, such as ordinary land oil and gas branch pipelines.
API 5L X46 Pipe: used for pipelines that require higher strength to withstand a certain pressure, such as medium and long-distance land oil and gas pipelines, or pipelines inside petrochemical plants that have certain requirements for pipeline strength, etc.
API 5L PSL1 X46 round steel tube
