Commonly used materials for welded pipes are: Q235A, Q235C, Q235B, 16Mn, 20#, Q345, L245, L290, X42, X46, X60, X80, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc.

Common classification of welded pipes:

The billet of welded steel pipe is steel plate or strip steel, which is divided into furnace welded pipe, electric welding (resistance welding) pipe and automatic arc welded pipe due to different welding processes. Due to the different welding forms, it is divided into two types: straight seam welded pipe and spiral welded pipe. Because of its end shape, it is divided into circular welded pipe and special-shaped (square, flat, etc.) welded pipe. Welded pipes are divided into the following varieties due to their different materials and uses:

• GB/T3091-2008 (Welded steel pipes for low-pressure fluid transportation): mainly used for conveying general low-pressure fluids such as water, gas, air, oil and heating water or steam, and other purpose pipes. Its representative material is Q235A grade steel.
• GB/T14291-2006 (Welded Steel Pipe for Mine Fluid Conveying): Mainly used for mine air pressure, drainage, etc. It represents the material Q235A, B grade steel.
• GB/T12770-2002 (stainless steel welded steel pipe for mechanical structure): mainly used for machinery, automobiles, bicycles, furniture, decoration of hotels and restaurants, and other mechanical parts and structural parts. Its representative materials are 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc.
• GB/T12771-1991 (stainless steel welded steel pipe for fluid conveying): mainly used for conveying low-pressure corrosive medium. The representative materials are 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, 0017Cr17Ni14Mo2, etc.
• In addition, welded stainless steel pipes for decoration (GB/T 18705-2002), stainless steel welded pipes for architectural decoration (JG/T 3030-1995), and welded steel pipes for heat exchangers (YB4103-2000).

Specification: