Commonly used materials for low temperature seamless steel pipes

Compared with carbon structural steel, the steel used in low-temperature alloy steel pipes has the advantages of high strength, good overall performance, long service life, wide application range, and relatively economical performance.
Low-temperature seamless steel pipes generally use low-alloy high-strength structural steel (GB/T1591-1994). Commonly used materials for low-temperature pipes are: Q345B, Q345C, Q345D, Q345E, and A33Gr6. This steel is often rolled into plates, profiles, seamless steel pipes, etc., and is widely used in bridges, ships, boilers, vehicles and important building structures.

In addition to a certain amount of basic elements such as silicon or manganese, this type of steel also contains other elements suitable for my country's resource conditions. Trace elements such as vanadium (V), niobium (Nb), titanium (Ti), aluminum (Al), molybdenum (Mo), nitrogen (N), and rare earth (RE). According to chemical composition and performance requirements, its grades include Q295A, B, Q345A, B, C, D, E, Q390A, B, C, D, E, Q420A, B, C, D, E, Q460C, D, E, etc. The steel grade indicates that its meaning is the same as that of carbon structural steel.

Grain-refining trace elements such as V, Nb, Ti, Al, etc. In this type of steel, in addition to A and B grade steel, the C, D, and E grade steel should contain at least one of them; in order to improve the performance of the steel , one of them can also be added to grade A and B steel. In addition, the residual element content of Cr, Ni, and Cu in this type of steel is not more than 0.30%. Q345A, B, C, D, and E are the representative grades of this type of steel. Among them, A and B-grade steel are usually called 16Mn; C-grade and above steels need to add more than one trace element, and add a low-temperature impact property to their mechanical properties.