1 .Brief introduction of structural pipe

Seamless pipe for structure (GB/T8162-2008) is used for the general structure and mechanical structure of the seamless pipe.Seamless steel tube is divided into a variety of different uses.

Stainless steel seamless pipe for structure (GB/T14975-2002) is a hot-rolled (extruded, expanded) and cold-drawn (rolled) seamless pipe made of stainless steel used in chemical, petroleum, textile, medical, food, machinery and other industries, corrosion-resistant pipes and structural parts and components.

GB/T8162-2008 (seamless pipe for structure) is mainly used for general structure and mechanical structure.Its representative material (brand) : carbon steel 20, 45 steel, Q235, alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo and so on.

Seamless steel pipe

Because of its manufacturing process is different, it is divided into hot rolled (extruded) seamless steel tube and cold drawn (rolled) seamless steel tube two kinds.Cold-drawn (rolled) pipe is divided into circular pipe and special-shaped pipe two kinds.

A.Overview of process flow

Hot rolling (extruded seamless steel tube) : round tube billet → heating → perforation → three-roll cross rolling, continuous rolling or extrusion → tube stripping → sizing (or reducing) → cooling → blank tube → straightening → water pressure test (or defect detection) → marking → storage.

Cold drawing (rolling) seamless steel tube: round tube billet → heating → perforation → heading → annealing → pickling → oiling (copper plating) → multi-pass cold drawing (cold rolling) → blank tube → heat treatment → straightening → water pressure test (flaw detection) → marking → storage.

2 .Standards

1, GB: seamless steel tube for structure: GB8162-2008 2, seamless steel tube for conveying fluid: GB8163-2008 3, seamless steel tube for boiler: GB3087-2008 4, high pressure seamless tube for boiler:5, chemical fertilizer equipment for high pressure seamless steel pipe: GB6479-2000 6, geological drilling for seamless steel pipe: YB235-70 7, oil drilling for seamless steel pipe: YB528-65 8, petroleum cracking seamless steel pipe:10. Seamless steel pipe for automobile semi-shaft: GB3088-1999 11. Seamless steel pipe for ship: GB5312-1999 12.13, all kinds of alloy tube 16Mn, 27SiMn,15CrMo, 35CrMo, 12CrMov, 20G, 40Cr, 12Cr1MoV,15CrMo

In addition,There are also GB/T17396-2009 (hot-rolled seamless steel tube for hydraulic prop), GB3093-1986 (high-pressure seamless steel tube for diesel engine), GB/T3639-1983 (cold-drawn or cold-rolled precision seamless steel tube), GB/T3094-1986 (Cold-drawn seamless steel tubes, special-shaped steel tubes), GB/T8713-1988 (seamless steel tubes with precision inner diameter for hydraulic and pneumatic cylinders), GB13296-1991 (seamless stainless steel tubes for boilers and heat exchangers), GB/T14975-1994 (seamless stainless steel tubes for structural use), GB/T14976-1994 (Seamless stainless steel tubes with precision inner diameter for hydraulic and pneumatic cylinders)Seamless stainless steel tubes for fluid transportation GB/T5035-1993 (seamless steel tubes for automobile axle bushing), API SPEC5CT-1999 (specification for casing and tubing), etc.

2, American standard: ASTM A53 — ASME SA53 — Boiler and Pressure Vessel code main production grade or steel class: A53A, A53B, SA53A, SA53B

Seamless tube weight formula: [(outer diameter - wall thickness)* wall thickness]*0.02466=kg/ m (weight per meter)