Main location

Shanghai, China

Send email to us by

sales@sunnysteel.com

Know-how and best quality

tel:+8621 3378 0199

Seamless steel pipe

Seamless pipes are derived from solid steel that is in sheet or bar form and is formed into a solid round shape known as “billets” which are then heated and cast over a form such as a piercing rod to create a hollow tube or shell.

Boiler tubes

Boiler tubes are used in heat exchange appliances in which the energy is transferred from one medium to the other.

Heat Exchanger Tubes

Heat exchange tubes are intended for heating or cooling process fluids, they are for example suitable for closed circuit cooling of electrical equipment using demineralised water and for cooling water soluble oil solutions in quenching tanks.
Ready to honed tube

Honed Tube

Honed tube is well known as hydraulic cylinder tube in many industries.

U-bend tubes

Each U bend tube of our range is rigorously quality checked by our team of talented professionals on every stage of production to deliver the clients defect free best quality products.

Seamless pipes by standards include: ASTM, JIS, DIN, GB and customers for international

Seamless pipes are extensively applied for the nuclear device, gas, petrochemical, ship building and boiler industries.

How to make seamless pipe & tubes?

According to manufacuring process of seamless pipe,seamless pipe can be divided into hot rolled seamless tube and cold drawn seamless tube.

Seamless steel pipe is alos called CDS pipes (Cold drawn seamless pipe). It’s is used widely in maching parts, shafts, bearings, cylinders having strength of 75000 PSD tensile. It is a solid carbon steel rod which is pushed on to the mandrel to form the shape of tube. It is availabe in different sizes.

Cold drawn seamless steel tubes process

round tube → heating → ​​perforation → Heading → ​​annealing → ​​pickling → ​​oiled (copper) → multi-pass cold drawn (cold rolled) → blank tube → heat treatment → straightening →hydrostatic testing (testing) → mark → storage.

The general cold strip mills, volume should go through continuous annealing (CAPL unit) to eliminate cold hardening and rolling stress, or batch annealing reach the mechanical properties of the corresponding standard specifies. Cold rolled steel surface quality, appearance, dimensional accuracy better than hot-rolled plate, and right-rolled thin product thickness is about 0.18mm, so the majority of users favor.

Hot-rolled seamless steel pipe production base deformation process can be summarized as three stages: perforation, extension and finishing.


Hot rolled seamless steel pipe deformed process

Hot-rolled seamless steel pipe production base deformation process can be summarized as three stages: perforation, extension and finishing.

The main purpose of the perforation process is to become a solid round billet piercing hollow shell. Capillary in the specifications, accuracy and surface quality can not meet the requirements of the finished product, further improvements are needed to deform the metal through. The main purpose of the stretching machine is further reduced sectional view (main compression wall) for a larger axial extension, so that the capillary improved dimensional accuracy, surface quality and organizational performance.


Condition on delivery:

Term Symbol Explanation
Cold-finished/hard
(cold-finished as-drawn)
BK No heat treatment after the last cold-forming process. The tubes therefore have only low deformability.
Cold-finished/soft
(lightly cold-worked)
BKW After the last heat treatment there is a light finishing pass (cold drawing) With proper subsequent processing, the tube can be cold-formed (e.g. bent, expanded) within certain limits.
Annealed GBK After the final cold-forming process the tubes are annealed in a controlled atmosphere or under vacuum.
Normalized NBK The tubes are annealed above the upper transformation point in a controlled atmosphere or under vacuum.

The general cold strip mills, volume should go through continuous annealing (CAPL unit) to eliminate cold hardening and rolling stress, or batch annealing reach the mechanical properties of the corresponding standard specifies. Cold rolled steel surface quality, appearance, dimensional accuracy better than hot-rolled plate, and right-rolled thin product thickness is about 0.18mm, so the majority of users favor.

Cold rolled steel coil substrate products deep processing of high value-added products. Such as electro-galvanized, hot dip galvanized, electro-galvanized fingerprint resistant, painted steel roll damping composite steel, PVC laminating steel plates, etc., so that the excellent quality of these products has a beautiful, high resistance to corrosion, has been widely used.

Cold rolled steel coil finishing after annealing, cut the head, tail, trimming, flattening, smooth, heavy volume, or longitudinal clipboard. Cold-rolled products are widely used in automobile manufacturing, household electrical appliances, instruments, switches, buildings, office furniture and other industries. Steel plate strapping package weight of 3 to 5 tons. Flat sub-volume typically 3 to 10 tons / volume. Coil diameter 6m.

Sunny Steel explains Seamless steel pipe

Seamless pipe vs Welded pipe

A Seamless steel pipe is extruded and drawn from a billet whereas a welded pipe is produced from a strip that is roll formed and welded to produce a pipe.
  • Since a Seamless steel pipe offers a higher range of safety measures it is more expensive than a welded tube.
  • A Seamless steel pipe is relatively short in length, whereas welded tubes can be manufactured in long continuous lengths.
  • A Seamless steel pipe generally doesn’t show any sign of corrosion until and unless it is subjected to a highly corrosive environment, whereas the weld area in the welded tube is much more prone to corrosion attacks.
  • A welded area is considered to be inhomogeneous, thus it exhibits a different malleability and less corrosion resistance as well as greater dimensional variation.
  • A Seamless steel pipe eliminates any such issues and thus offers high corrosion resistance.

Characteristics of seamless steel pipe

Seamless steel pipe is actually a hollow cross section and both sides of the expansion of the resistance to air, steam, water and other weak corrosive media and acid, alkali, salt and other chemical corrosion medium corrosion of steel pipe.
  • High precision can do small batch production.
  • Smaller diameter.
  • Weldability strong, high compression capability.
  • Steel pipe superior performance, relatively dense metal.
  • Steel Cross area is more complex.
  • High precision cold drawn products, good surface quality.

Mechanical properties of the seamless steel tube

The mechanical properties of the seamless steel tube is a important indicator that ensure seamless pipe end-use properties (mechanical properties), which depends on the chemical composition and heat treatment of steel.

Precision cut lengths

The automotive and automotive components supplier industries represent the significant area of use for precision cut lengths, they could also be used in the domestic appliance industry and mechanical engineering.

Quality testing for seamless pipe

Seamless steel pipe quality testing is a very important step, and for its detection method is also very particular to now all three – ultrasonic testing, eddy current testing, magnetic flux leakage testing, specific circumstances.