Seamless steel pipe classification(1)

    Seamless steel pipes are divided into hot-rolled (extruded) seamless steel pipes and cold-drawn (rolled) seamless steel pipes due to their different manufacturing processes. Cold drawn (rolled) tubes are divided into round tubes and special-shaped tubes. Seamless steel pipes are divided into the following varieties due to their different uses:

1. GB/T8162-1999 (Seamless steel pipe for structure). Mainly used for general structure and mechanical structure. Its representative materials (brands): carbon steel, 20, 45 steel; alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.

2. GB/T8163-1999 (Seamless steel pipe for conveying fluid). Mainly used to transport fluid pipelines on engineering and large equipment. The representative material (brand) is 20, Q345, etc.

3. GB3087-1999 (Seamless steel tubes for low and medium pressure boilers) is used to manufacture superheated steam tubes, boiling water tubes for low and medium pressure boilers of various structures and superheated steam tubes for locomotive boilers, large smoke tubes, small smoke tubes and arch bricks High-quality carbon structural steel hot-rolled and cold-drawn (rolled) seamless steel tubes for pipes. Representative materials are 10 and 20 steel.

4. GB5310-1995 (Seamless steel tubes for high-pressure boilers) is a seamless steel tube of high-quality carbon steel, alloy steel and stainless heat-resistant steel for the heating surface of water tube boilers with high pressure and above. Representative materials are 20G, 12Cr1MoVG, 15CrMoG, etc.

5. GB1479-2000 (Seamless steel pipe for high-pressure fertilizer equipment) is a high-quality carbon structural steel and alloy steel seamless steel pipe suitable for chemical equipment and pipelines with a working temperature of -40 to 400 ℃ and a working pressure of 10 to 30 Ma. Representative materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc.