What is cold drawn seamless steel pipe?

What is cold drawn seamless steel pipe?

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

Product introduction of Cold drawn seamless steel pipe

If you want to obtain small-diameter seamless steel pipes with smaller size and better quality, you must use cold rolling, cold drawing or a combination of the two. Cold rolling is usually carried out on a two-roll mill, and the steel pipe is rolled in an annular pass composed of a variable cross-section circular groove and a fixed conical head. Cold drawing is usually performed on a 0.5 to 100T single-chain or double-chain cold drawing machine.
High-quality carbon structural steel cold-drawn seamless pipes are mainly made of No. 10, No. 20, No. 35, and No. 45 steel. In addition to ensuring the chemical composition and mechanical properties, hydrostatic testing, curling, flaring, flattening, etc. test.

Seamless pipe weight calculation: (outer diameter-wall thickness)*wall thickness*0.02466=kg/meter (weight per meter)

1.Production and manufacturing methods

According to different production methods, it can be divided into hot-rolled pipes, cold-rolled pipes, cold-drawn pipes, extruded pipes, etc. The biggest difference between cold-drawn seamless steel pipes and hot-rolled seamless steel pipes is that the precision of cold-drawn seamless steel pipes is better than that of hot-rolled seamless steel pipes. The general accuracy of cold-drawn seamless steel pipes is around 20 wires, while hot-rolled seamless steel pipes have no The precision of seamed pipes is around 100 wires, so cold-drawn seamless steel pipes are the first choice for mechanical processing manufacturing and parts manufacturing.

1.1. Hot-rolled seamless pipes are generally produced on automatic pipe rolling units. The solid tube blank is inspected and surface defects are removed, cut into the required length, centered on the perforated end of the tube blank, and then sent to the heating furnace for heating and piercing on the punching machine. It continues to rotate and advance during piercing holes. Under the influence of the rollers and the end, the tube blank is hollow gradually, which is called gross pipe. Then it is sent to the automatic pipe rolling machine to continue rolling. Finally, the wall thickness is evened by the leveling machine, and the diameter is determined (reduced) by the sizing (reducing) machine to meet the specification requirements. The use of continuous pipe rolling units to produce hot-rolled seamless steel pipes is a more advanced method.
1.2. If you want to obtain seamless pipes with smaller size and better quality.
1.3. The extrusion method is to place the heated tube blank in a closed extrusion cylinder, and the perforation rod and the extrusion rod move together to make the extrusion part extruded from the smaller die hole. This method can produce steel pipes with smaller diameters.

2.Use

2.1. Seamless pipes are widely used. General-purpose seamless pipes are rolled from ordinary carbon structural steel, low alloy structural steel or alloy structural steel, with the largest output, and are mainly used as pipes or structural parts for transporting fluids.
2.2. It is supplied in three categories according to different uses: a. Supplied according to chemical composition and mechanical properties; b. Supplied according to mechanical properties; c. Supplied according to hydraulic pressure test. If the steel pipes supplied according to categories a and b are used to withstand liquid pressure, they must also undergo a hydrostatic test.
2.3. Special-purpose seamless pipes include seamless pipes for boilers, seamless pipes for geology, and seamless pipes for petroleum.

3.Type

3.1. Seamless steel pipes can be divided into hot-rolled pipes, cold-rolled pipes, cold-drawn pipes, extruded pipes, etc. according to different production methods.
3.2. According to the shape, there are round tubes and special-shaped tubes. In addition to square tubes and rectangular tubes, special-shaped tubes also include oval tubes, semi-circular tubes, triangular tubes, hexagonal tubes, convex-shaped tubes, plum-shaped tubes, etc.
3.3. According to different materials, they are divided into ordinary carbon structural pipes, low alloy structural pipes, high-quality carbon structural pipes, alloy structural pipes, stainless steel pipes, etc.
3.4. According to special purposes, there are boiler pipes, geological pipes, oil pipes, etc.

4. Specifications and appearance quality

Seamless pipes are in accordance with GB/T8162-2018 regulations
4.1. Specifications: The outer diameter of hot-rolled pipe is 32~630mm. Wall thickness 2.5~75mm. The outer diameter of cold rolled (cold drawn) pipe is 5~200mm. Wall thickness 2.5~12mm.
4.2. Appearance quality: The inner and outer surfaces of the steel pipe must not have cracks, folds, roll folds, separation layers, hair lines and scarring defects. These defects should be completely removed, and the wall thickness and outer diameter should not exceed negative deviations after removal.
4.3. Both ends of the steel pipe should be cut at right angles and burrs should be removed. Steel pipes with wall thickness greater than 20mm are allowed to be cut by gas cutting and hot sawing. It is also possible not to cut the head after agreement between the supply and demand parties.
4.4. The "surface quality" of cold-drawn or cold-rolled precision seamless steel pipes refers to GB3639-2018.

5. Chemical composition inspection

5.1. The chemical composition of domestic seamless pipes supplied according to chemical composition and mechanical properties, such as No. 10, 15, 20, 25, 30, 35, 40, 45 and 50 steel, shall comply with the provisions of GB/T699-88. Imported seamless pipes are inspected according to relevant standards stipulated in the contract. The chemical composition of 09MnV, 16Mn, and 15MnV steel should comply with the regulations of GB1591-79.
5.2. For specific analysis methods, please refer to the relevant parts of GB223-84 "Chemical Analysis Methods for Steel and Alloys".
5.3. For analysis deviations, refer to GB222-84 "Permissible deviations of chemical composition of samples and finished products for chemical analysis of steel".

6.Physical properties

6.1. Domestic seamless pipes and ordinary carbon steel supplied according to structural performance are manufactured according to Class A steel of GB/T700-88 (but must ensure that the sulfur content does not exceed 0.050% and the phosphorus content does not exceed 0.045%), and its mechanical The performance should comply with the values specified in the GB8162-2008 table.
6.2. Domestic seamless pipes supplied according to the hydraulic pressure test must ensure the hydraulic pressure test specified in the standard.
6.3. The physical performance inspection of imported seamless pipes shall be carried out in accordance with the relevant standards stipulated in the contract.

7.Import and export situation

7.1. Generally, the import volume of seamless pipes is large. The main importing countries are Germany and Japan. European countries such as Romania, Russia, Switzerland, France, Spain, Czech Republic, Yugoslavia, Hungary and other countries all import. There are also small quantities imported from Argentina, Mexico and other countries in South America.
7.2. According to the different requirements of my country's consumer units, there are more than 100 specifications of imported seamless pipes. Common specifications are 15922mm, 1595mm, and 15918mm. 114.38mm, 114.310mm, 114.313mm. The length generally ranges from 5 to 8m or 4 to 7m. Mainly hot rolled carbon structure, and ST65. The smallest diameter of imported specifications is 305mm, and the largest is 47813mm.
7.3. A small amount of seamless pipes with smaller diameters and thin walls have been imported from France and Spain, such as 183mm, 223mm, 26.93mm, etc. The general rules of the German Mannesmann Steel Pipe Works apply.
7.4. Seamless pipes imported from Hungary and Japan often refer to DIN2448 and DIN1629.
7.5. In import claim cases, the main quality problems of imported seamless pipes include: unqualified chemical composition, splitting in the flattening test, low tensile strength, severe corrosion and pits, etc.

Packaging standards

According to GB2102-88 regulations. There are three types of steel pipe packaging: bundling, boxing, oiled bundling or oiled boxing.

Differences and features

The difference between cold drawn precision steel pipes and ordinary seamless steel pipes:
1. The main feature of ordinary seamless steel pipes is that they have no welding seams and can withstand greater pressure. Products can be very rough as cast or cold drawn parts.
2. Cold-drawn precision steel pipes are products that have appeared in recent years. They mainly have strict tolerances and roughness for the inner hole and outer wall dimensions.
Characteristics of cold drawn (rolled) precision steel pipes:
(1) The outer diameter is smaller.
(2) High precision and can be used for small batch production
(3) The cold drawn (rolled) finished product has high precision and good surface quality.
(4) The cross-sectional area of the steel pipe is more complex.
(5) The performance of steel pipes is superior and the metal is relatively dense.

Usual format

According to GB/T3639-2018 (cold drawn or cold rolled precision seamless steel pipe) standard, commonly used specifications and size table:

Cold drawn seamless steel pipe specification table

Φ4×0.5	Φ16×0.5	Φ26×1.8	Φ35×9.0	Φ48×5.0	Φ70×2.8	Φ90×10	Φ130×14	Φ190×14
Φ4×0.8	Φ16×0.8	Φ26×2.0	Φ35×10	Φ48×5.5	Φ70×3.0	Φ90×12	Φ130×16	Φ190×16
Φ4×1.0	Φ16×1.0	Φ26×2.2	Φ38×0.5	Φ48×6.0	Φ70×3.5	Φ90×14	Φ130×18	Φ190×18
Φ4×1.2	Φ16×1.2	Φ26×2.5	Φ38×0.8	Φ48×7.0	Φ70×4.0	Φ90×16	Φ140×2.5	Φ190×20
Φ5×0.5	Φ16×1.5	Φ26×2.8	Φ38×1.0	Φ48×8.0	Φ70×4.5	Φ95×2.0	Φ140×2.8	Φ190×22
Φ5×0.8	Φ16×1.8	Φ26×3.0	Φ38×1.2	Φ48×9.0	Φ70×5.0	Φ95×2.2	Φ140×3.0	Φ200×3.5
Φ5×1.0	Φ16×2.0	Φ26×3.5	Φ38×1.5	Φ48×10	Φ70×5.5	Φ95×2.5	Φ140×3.5	Φ200×4.0
Φ5×1.2	Φ16×2.2	Φ26×4.0	Φ38×1.8	Φ50×1.0	Φ70×6.0	Φ95×2.8	Φ140×4.0	Φ200×4.5
Φ6×0.5	Φ16×2.5	Φ26×4.5	Φ38×2.0	Φ50×1.2	Φ70×7.0	Φ95×3.0	Φ140×4.5	Φ200×5.0
Φ6×0.8	Φ16×2.8	Φ26×5.0	Φ38×2.2	Φ50×1.5	Φ70×8.0	Φ95×3.5	Φ140×5.0	Φ200×5.5
Φ6×1.0	Φ16×3.0	Φ26×5.5	Φ38×2.5	Φ50×1.8	Φ70×9.0	Φ95×4.0	Φ140×5.5	Φ200×6.0
Φ6×1.2	Φ16×3.5	Φ26×6.0	Φ38×2.8	Φ50×2.0	Φ70×10	Φ95×4.5	Φ140×6.0	Φ200×7.0
Φ6×1.5	Φ16×4.0	Φ26×7.0	Φ38×3.0	Φ50×2.2	Φ70×12	Φ95×5.0	Φ140×7.0	Φ200×8.0
Φ6×1.8	Φ16×4.5	Φ26×8.0	Φ38×3.5	Φ50×2.5	Φ70×14	Φ95×5.5	Φ140×8.0	Φ200×9.0
Φ6×2.0	Φ16×5.0	Φ28×0.5	Φ38×4.0	Φ50×2.8	Φ75×1.0	Φ95×6.0	Φ140×9.0	Φ200×10
Φ7×0.5	Φ16×5.5	Φ28×0.8	Φ38×4.5	Φ50×3.0	Φ75×1.2	Φ95×7.0	Φ140×10	Φ200×12
Φ7×0.8	Φ16×6.0	Φ28×1.0	Φ38×5.0	Φ50×3.5	Φ75×1.5	Φ95×8.0	Φ140×12	Φ200×14
Φ7×1.0	Φ18×0.5	Φ28×1.2	Φ38×5.5	Φ50×4.0	Φ75×1.8	Φ95×9.0	Φ140×14	Φ200×16
Φ7×1.2	Φ18×0.8	Φ28×1.5	Φ38×6.0	Φ50×4.5	Φ75×2.0	Φ95×10	Φ140×16	Φ200×18
Φ7×1.5	Φ18×1.0	Φ28×1.8	Φ38×7.0	Φ50×5.0	Φ75×2.2	Φ95×12	Φ140×18	Φ200×20
Φ7×1.8	Φ18×1.2	Φ28×2.0	Φ38×8.0	Φ50×5.5	Φ75×2.5	Φ95×14	Φ150×3.0	Φ200×22
Φ7×2.0	Φ18×1.5	Φ28×2.2	Φ38×9.0	Φ50×6.0	Φ75×2.8	Φ95×16	Φ150×3.5
Φ8×0.5	Φ18×1.8	Φ28×2.5	Φ38×10	Φ50×7.0	Φ75×3.0	Φ95×18	Φ150×4.0
Φ8×0.8	Φ18×2.0	Φ28×2.8	Φ40×0.5	Φ50×8.0	Φ75×3.5	Φ100×2.0	Φ150×4.5
Φ8×1.0	Φ18×2.2	Φ28×3.0	Φ40×0.8	Φ50×9.0	Φ75×4.0	Φ100×2.2	Φ150×5.0
Φ8×1.2	Φ18×2.5	Φ28×3.5	Φ40×1.0	Φ50×10	Φ75×4.5	Φ100×2.5	Φ150×5.5
Φ8×1.5	Φ18×2.8	Φ28×4.0	Φ40×1.2	Φ55×1.0	Φ75×5.0	Φ100×2.8	Φ150×6.0
Φ8×1.8	Φ18×3.0	Φ28×4.5	Φ40×1.5	Φ55×1.2	Φ75×5.5	Φ100×3.0	Φ150×7.0
Φ8×2.0	Φ18×3.5	Φ28×5.0	Φ40×1.8	Φ55×1.5	Φ75×6.0	Φ100×3.5	Φ150×8.0
Φ8×2.2	Φ18×4.0	Φ28×5.5	Φ40×2.0	Φ55×1.8	Φ75×7.0	Φ100×4.0	Φ150×9.0
Φ8×2.5	Φ18×4.5	Φ28×6.0	Φ40×2.2	Φ55×2.0	Φ75×8.0	Φ100×4.5	Φ150×10
Φ9×0.5	Φ18×5.0	Φ28×7.0	Φ40×2.5	Φ55×2.2	Φ75×9.0	Φ100×5.0	Φ150×12
Φ9×0.8	Φ18×5.5	Φ28×8.0	Φ40×2.8	Φ55×2.5	Φ75×10	Φ100×5.5	Φ150×14
Φ9×1.0	Φ18×6.0	Φ30×0.5	Φ40×3.0	Φ55×2.8	Φ75×12	Φ100×6.0	Φ150×16
Φ9×1.2	Φ20×0.5	Φ30×0.8	Φ40×3.5	Φ55×3.0	Φ75×14	Φ100×7.0	Φ150×18
Φ9×1.5	Φ20×0.8	Φ30×1.0	Φ40×4.0	Φ55×3.5	Φ75×16	Φ100×8.0	Φ150×20
Φ9×1.8	Φ20×1.0	Φ30×1.2	Φ40×4.5	Φ55×4.0	Φ80×1.0	Φ100×9.0	Φ160×3.0
Φ9×2.0	Φ20×1.2	Φ30×1.5	Φ40×5.0	Φ55×4.5	Φ80×1.2	Φ100×10	Φ160×3.5
Φ9×2.2	Φ20×1.5	Φ30×1.8	Φ40×5.5	Φ55×5.0	Φ80×1.5	Φ100×12	Φ160×4.0
Φ9×2.5	Φ20×1.8	Φ30×2.0	Φ40×6.0	Φ55×5.5	Φ80×1.8	Φ100×14	Φ160×4.5
Φ9×2.8	Φ20×2.0	Φ30×2.2	Φ40×7.0	Φ55×6.0	Φ80×2.0	Φ100×16	Φ160×5.0
Φ10×0.5	Φ20×2.2	Φ30×2.5	Φ40×8.0	Φ55×7.0	Φ80×2.2	Φ100×18	Φ160×5.5
Φ10×0.8	Φ20×2.5	Φ30×2.8	Φ40×9.0	Φ55×8.0	Φ80×2.5	Φ110×2.0	Φ160×6.0
Φ10×1.0	Φ20×2.8	Φ30×3.0	Φ40×10	Φ55×9.0	Φ80×2.8	Φ110×2.2	Φ160×7.0
Φ10×1.2	Φ20×3.0	Φ30×3.5	Φ42×1.0	Φ55×10	Φ80×3.0	Φ110×2.5	Φ160×8.0
Φ10×1.5	Φ20×3.5	Φ30×4.0	Φ42×1.2	Φ55×12	Φ80×3.5	Φ110×2.8	Φ160×9.0
Φ10×1.8	Φ20×4.0	Φ30×4.5	Φ42×1.5	Φ60×1.0	Φ80×4.0	Φ110×3.0	Φ160×10
Φ10×2.0	Φ20×4.5	Φ30×5.0	Φ42×1.8	Φ60×1.2	Φ80×4.5	Φ110×3.5	Φ160×12
Φ10×2.2	Φ20×5.0	Φ30×5.5	Φ42×2.0	Φ60×1.5	Φ80×5.0	Φ110×4.0	Φ160×14
Φ10×2.5	Φ20×5.5	Φ30×6.0	Φ42×2.2	Φ60×1.8	Φ80×5.5	Φ110×4.5	Φ160×16
Φ10×2.8	Φ20×6.0	Φ30×7.0	Φ42×2.5	Φ60×2.0	Φ80×6.0	Φ110×5.0	Φ160×18
Φ10×3.0	Φ20×7.0	Φ30×8.0	Φ42×2.8	Φ60×2.2	Φ80×7.0	Φ110×5.5	Φ160×20
Φ12×0.5	Φ22×0.5	Φ30×9.0	Φ42×3.0	Φ60×2.5	Φ80×8.0	Φ110×6.0	Φ170×3.0
Φ12×0.8	Φ22×0.8	Φ30×10	Φ42×3.5	Φ60×2.8	Φ80×9.0	Φ110×7.0	Φ170×3.5
Φ12×1.0	Φ22×1.0	Φ32×0.5	Φ42×4.0	Φ60×3.0	Φ80×10	Φ110×8.0	Φ170×4.0
Φ12×1.2	Φ22×1.2	Φ32×0.8	Φ42×4.5	Φ60×3.5	Φ80×12	Φ110×9.0	Φ170×4.5
Φ12×1.5	Φ22×1.5	Φ32×1.0	Φ42×5.0	Φ60×4.0	Φ80×14	Φ110×10	Φ170×5.0
Φ12×1.8	Φ22×1.8	Φ32×1.2	Φ42×5.5	Φ60×4.5	Φ80×16	Φ110×12	Φ170×5.5
Φ12×2.0	Φ22×2.0	Φ32×1.5	Φ42×6.0	Φ60×5.0	Φ85×1.5	Φ110×14	Φ170×6.0
Φ12×2.2	Φ22×2.2	Φ32×1.8	Φ42×7.0	Φ60×5.5	Φ85×1.8	Φ110×16	Φ170×7.0
Φ12×2.5	Φ22×2.5	Φ32×2.0	Φ42×8.0	Φ60×6.0	Φ85×2.0	Φ110×18	Φ170×8.0
Φ12×2.8	Φ22×2.8	Φ32×2.2	Φ42×9.0	Φ60×7.0	Φ85×2.2	Φ120×2.0	Φ170×9.0
Φ12×3.0	Φ22×3.0	Φ32×2.5	Φ42×10	Φ60×8.0	Φ85×2.5	Φ120×2.2	Φ170×10
Φ12×3.5	Φ22×3.5	Φ32×2.8	Φ45×1.0	Φ60×9.0	Φ85×2.8	Φ120×2.5	Φ170×12
Φ12×4.0	Φ22×4.0	Φ32×3.0	Φ45×1.2	Φ60×10	Φ85×3.0	Φ120×2.8	Φ170×14
Φ14×0.5	Φ22×4.5	Φ32×3.5	Φ45×1.5	Φ60×12	Φ85×3.5	Φ120×3.0	Φ170×16
Φ14×0.8	Φ22×5.0	Φ32×4.0	Φ45×1.8	Φ65×1.0	Φ85×4.0	Φ120×3.5	Φ170×18
Φ14×1.0	Φ22×5.5	Φ32×4.5	Φ45×2.0	Φ65×1.2	Φ85×4.5	Φ120×4.0	Φ170×20
Φ14×1.2	Φ22×6.0	Φ32×5.0	Φ45×2.2	Φ65×1.5	Φ85×5.0	Φ120×4.5	Φ180×3.5
Φ14×1.5	Φ22×7.0	Φ32×5.5	Φ45×2.5	Φ65×1.8	Φ85×5.5	Φ120×5.0	Φ180×4.0
Φ14×1.8	Φ25×0.5	Φ32×6.0	Φ45×2.8	Φ65×2.0	Φ85×6.0	Φ120×5.5	Φ180×4.5
Φ14×2.0	Φ25×0.8	Φ32×7.0	Φ45×3.0	Φ65×2.2	Φ85×7.0	Φ120×6.0	Φ180×5.0
Φ14×2.2	Φ25×1.0	Φ32×8.0	Φ45×3.5	Φ65×2.5	Φ85×8.0	Φ120×7.0	Φ180×5.5
Φ14×2.5	Φ25×1.2	Φ32×9.0	Φ45×4.0	Φ65×2.8	Φ85×9.0	Φ120×8.0	Φ180×6.0
Φ14×2.8	Φ25×1.5	Φ32×10	Φ45×4.5	Φ65×3.0	Φ85×10	Φ120×9.0	Φ180×7.0
Φ14×3.0	Φ25×1.8	Φ35×0.5	Φ45×5.0	Φ65×3.5	Φ85×12	Φ120×10	Φ180×8.0
Φ14×3.5	Φ25×2.0	Φ35×0.8	Φ45×5.5	Φ65×4.0	Φ85×14	Φ120×12	Φ180×9.0
Φ14×4.0	Φ25×2.2	Φ35×1.0	Φ45×6.0	Φ65×4.5	Φ85×16	Φ120×14	Φ180×10
Φ14×4.5	Φ25×2.5	Φ35×1.2	Φ45×7.0	Φ65×5.0	Φ90×1.5	Φ120×16	Φ180×12
Φ15×0.5	Φ25×2.8	Φ35×1.5	Φ45×8.0	Φ65×5.5	Φ90×1.8	Φ120×18	Φ180×14
Φ15×0.8	Φ25×3.0	Φ35×1.8	Φ45×9.0	Φ65×6.0	Φ90×2.0	Φ130×2.5	Φ180×16
Φ15×1.0	Φ25×3.5	Φ35×2.0	Φ45×10	Φ65×7.0	Φ90×2.2	Φ130×2.8	Φ180×18
Φ15×1.2	Φ25×4.0	Φ35×2.2	Φ48×1.0	Φ65×8.0	Φ90×2.5	Φ130×3.0	Φ180×20
Φ15×1.5	Φ25×4.5	Φ35×2.5	Φ48×1.2	Φ65×9.0	Φ90×2.8	Φ130×3.5	Φ190×3.5
Φ15×1.8	Φ25×5.0	Φ35×2.8	Φ48×1.5	Φ65×10	Φ90×3.0	Φ130×4.0	Φ190×4.0
Φ15×2.0	Φ25×5.5	Φ35×3.0	Φ48×1.8	Φ65×12	Φ90×3.5	Φ130×4.5	Φ190×4.5
Φ15×2.2	Φ25×6.0	Φ35×3.5	Φ48×2.0	Φ65×14	Φ90×4.0	Φ130×5.0	Φ190×5.0
Φ15×2.5	Φ25×7.0	Φ35×4.0	Φ48×2.2	Φ70×1.0	Φ90×4.5	Φ130×5.5	Φ190×5.5
Φ15×2.8	Φ25×8.0	Φ35×4.5	Φ48×2.5	Φ70×1.2	Φ90×5.0	Φ130×6.0	Φ190×6.0
Φ15×3.0	Φ26×0.5	Φ35×5.0	Φ48×2.8	Φ70×1.5	Φ90×5.5	Φ130×7.0	Φ190×7.0
Φ15×3.5	Φ26×0.8	Φ35×5.5	Φ48×3.0	Φ70×1.8	Φ90×6.0	Φ130×8.0	Φ190×8.0
Φ15×4.0	Φ26×1.0	Φ34×6.0	Φ48×3.5	Φ70×2.0	Φ90×7.0	Φ130×9.0	Φ190×9.0
Φ15×4.5	Φ26×1.2	Φ35×7.0	Φ48×4.0	Φ70×2.2	Φ90×8.0	Φ130×10	Φ190×10
Φ15×5.0	Φ26×1.5	Φ35×8.0	Φ48×4.5	Φ70×2.5	Φ90×9.0	Φ130×12	Φ190×12