Common materials for welded pipes are: Q235A, Q235C, Q235B, 16Mn, 20 #, Q345, L245, L290, X42, X46, X60, X80, 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb, etc.
The blank used for welded steel pipe is steel plate or strip steel, which is divided into furnace welded pipe,
electric resistance welded pipe and automatic arc welded pipe due to different welding processes. Because of its 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 round 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 pipe for low-pressure fluid transportation): mainly used for conveying water, gas, air, oil and heating hot water or steam and other generally low-pressure fluid and other use pipes. Its representative material is: Q235A grade steel.
GB / T14291-2006 (Welding Steel Pipe for Mine Fluid Transportation): Mainly used for straight seam welded steel pipes for mine pressure, drainage and shaft gas discharge. Its representative material is Q235A, B grade steel.
GB / T12770-2002 (stainless steel welded steel pipe for mechanical structure): mainly used for machinery, automobiles, bicycles, furniture, hotel and restaurant decoration and other mechanical parts and structural parts. Its representative materials are 0Cr13, 1Cr17, 00Cr19Ni11, 1Cr18Ni9, 0Cr18Ni11Nb and so on.
GB / T12771-1991 (stainless steel welded steel pipe for fluid transportation): mainly used to transport low-pressure corrosive media. Representative materials are 0Cr13, 0Cr19Ni9, 00Cr19Ni11, 00Cr17, 0Cr18Ni11Nb, 0017Cr17Ni14Mo2, etc.
In addition, welded stainless steel pipes for decoration (GB / T 18705-2002), welded stainless steel pipes for building decoration (JG / T 3030-1995), and welded steel pipes for heat exchangers (YB4103-2000).
Tips: In case ASTM A53 Grade B in ERW (electric resistance welded) pipe, the weld seam shall be done the heat treatment with a minimum 1000°F [540°C]. In this way the no untempered martensite remains.
In case ASTM A53 B pipe in cold expanded, then expansion should not exceed 1.5% of the required OD.
