Thick-walled seamless steel pipe

Hot-rolled thick-walled seamless steel pipes, cold-rolled thick-walled seamless steel pipes, cold-drawn thick-walled seamless steel pipes, extruded thick-walled seamless steel pipes, and stainless steel seamless steel pipes for pipe jacking structures (GB/T14975-2002) are used for Seamless steel pipes of general structure and mechanical structure are widely used in the hot-rolled (extruded, expanded) and cold-rolled (extruded, expanded) and cold-rolled stainless steel of corrosion-resistant pipes and structural parts and parts in the chemical, petroleum, textile, medical, food, machinery and other industries. Drawing (rolling) seamless steel tubes.

Stainless steel seamless steel pipe for fluid transportation (GB/T14976-2002) is a general seamless steel pipe used to transport water, oil, gas and other fluids. It is usually made of stainless steel hot rolled (extruded, expanded) and cold drawn (rolled) ) Seamless steel pipe.

Shaped seamless steel pipe is a general term for seamless steel pipes with cross-sectional shapes other than round pipes. According to the different shape and size of the steel pipe section, it can be divided into equal-walled special-shaped seamless steel pipe (code D), unequal-walled special-shaped seamless steel pipe (code BD), and variable diameter special-shaped seamless steel pipe (code BJ). Special-shaped seamless steel pipes are widely used in various structural parts, tools and mechanical parts. Compared with round pipes, special-shaped pipes generally have larger moments of inertia and section modulus, and have greater bending and torsion resistance, which can greatly reduce structural weight and save steel.

Commonly used thick-walled seamless steel pipe implementation standards

Seamless steel pipe for structure (GB/T8162-2008) is a seamless steel pipe used for general structure and mechanical structure.

Seamless steel pipe for fluid transportation (GB/T8163-2008) is a general seamless steel pipe used to transport water, oil, gas and other fluids.

Seamless steel pipes for low and medium pressure boilers (GB3087-2008) are used to manufacture superheated steam pipes, boiling water pipes for low and medium pressure boilers of various structures, and superheated steam pipes for locomotive boilers, large smoke pipes, small smoke pipes and arch brick pipes. High-quality carbon structural steel hot-rolled and cold-drawn (rolled) seamless steel tubes.

Seamless steel pipes for high-pressure boilers (GB5310-2008) are high-quality carbon steel, alloy steel and stainless heat-resistant steel seamless steel pipes for the heating surface of water-tube boilers with high pressure and above.

High-pressure seamless steel pipes for fertilizer equipment (GB6479-2000) are high-quality carbon structural steel and alloy steel seamless steel pipes suitable for chemical equipment and pipelines with a working temperature of -40 to 400 ℃ and a working pressure of 10 to 30 Ma.

Seamless steel tubes for petroleum cracking (GB9948-2006) are seamless steel tubes suitable for furnace tubes, heat exchangers and pipelines in petroleum refineries.

Steel pipes for geological drilling (YB235-70) are steel pipes used for core drilling by geological departments. They can be divided into drill pipes, drill collars, core pipes, casing pipes and sedimentation pipes according to their uses.

Seamless steel pipes for diamond core drilling (GB3423-82) are seamless steel pipes for drill pipes, core rods, and casings used for diamond core drilling.

Petroleum drilling pipe (YB528-65) is a seamless steel pipe that is thickened inside or outside at both ends of oil drilling. Steel pipes are divided into two types: wire and non-wired. Wired pipes are connected by joints, and non-wired pipes are connected with tool joints by butt welding.

Carbon steel seamless steel pipes for ships (GB5213-85) are carbon steel seamless steel pipes used in the manufacture of Class I pressure piping systems, Class II pressure piping systems, boilers and superheaters. The working temperature of carbon steel seamless steel pipe wall does not exceed 450℃, while that of alloy steel seamless steel pipe wall exceeds 450℃.

Seamless steel pipes for automobile axle sleeves (GB3088-82) are high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipes used in the manufacture of automobile axle sleeves and drive axle axle tubes.

High-pressure oil pipes for diesel engines (GB3093-86) are cold drawn seamless steel pipes used to manufacture high-pressure pipes for diesel engine injection systems.

Precision inner diameter seamless steel pipes for hydraulic and pneumatic cylinders (GB8713-88) are cold-drawn or cold-rolled precision seamless steel pipes with precise inner diameters for the manufacture of hydraulic and pneumatic cylinders.

Cold-drawn or cold-rolled precision seamless steel pipe (GB3639-83) is a cold-drawn or cold-rolled precision seamless steel pipe with high dimensional accuracy and good surface finish for mechanical structures and hydraulic equipment. The use of precision seamless steel pipes to manufacture mechanical structures or hydraulic equipment can greatly save machining man-hours, increase material utilization, and at the same time help improve product quality.

Thick-walled seamless steel pipes are classified by material

The steel pipes are made of 10#, 20#, 35#, 45#, which are called ordinary steel pipes and alloy steel pipes.

Production Process

The production process of general seamless steel pipes can be divided into two types: cold-drawn and hot-rolled. The production process of cold-rolled seamless steel pipes is generally more complicated than that of hot-rolled. The billet must first undergo three-roll continuous rolling, and then it must be extruded. In the sizing test, if the surface does not respond to cracks, the pipe will be cut by a cutting machine and cut into a blank of about one meter in length. Then enter the annealing process, the annealing should be pickled with acid liquid. When pickling, pay attention to whether there is a lot of blistering on the surface. If there is a lot of blistering, it means that the quality of the steel pipe does not meet the response standard. In appearance, cold-rolled seamless steel pipes are shorter than hot-rolled seamless steel pipes. The wall thickness of cold-rolled seamless steel pipes is generally smaller than that of hot-rolled seamless steel pipes, but the surface looks brighter than thick-walled seamless steel pipes. Much rough, without too many burrs.

The delivery state of hot-rolled seamless steel pipes is generally delivered after heat treatment in the hot-rolled state. After the quality inspection, the hot-rolled seamless steel pipes must be strictly hand-selected by the staff. After the quality inspection, the surface must be oiled, and then followed by multiple cold drawing experiments. After the hot-rolling treatment, the piercing experiment must be carried out. , If the perforation diameter is too large, it must be straightened. After straightening, it is transferred by the conveyor to the flaw detection machine for flaw detection experiment. Labels are attached, specifications are arranged, and then placed in the warehouse.