GB 9948 Seamless Steel Pipe

GB 9948 Seamless Steel Pipe

GB 9948 seamless steel pipe refers to a type of seamless steel pipe that conforms to the GB 9948 standard.

GB 9948 is a Chinese national standard that specifies the requirements for seamless steel pipes used in petroleum cracking processes. The standard is officially known as GB/T 9948-2013, and it replaced the previous version GB 9948-2006. It was published on September 18, 2013, and came into effect on July 1, 2014.

Scope of GB/T 9948-2013

This standard defines the classification, nomenclature, dimensions, shape, weight, technical requirements, testing methods, inspection rules, packaging, marking, and quality certificates for seamless steel pipes used in petroleum cracking. It is applicable to seamless steel pipes used in petrochemical furnace tubes, heat exchangers, and pressure pipelines.

Main Components of the Standard

Changes from the Previous Edition (GB 9948-2006)

This standard is proposed by the China Iron and Steel Industry Association and is under the jurisdiction of the National Steel Standardization Technical Committee (SAC/TC 183). The main drafting units include companies such as Panzhihua Iron and Steel Group, Ansteel Group, and others.

Uncured Pipes for Cracking Petroleum (GB9948-88) is a furnace tube, heat exchanger and seamless pipe for refineries.

Applications

GB 9948 seamless steel pipes are primarily used in petroleum cracking applications, such as in boilers, heat exchangers, and fluid pipelines of petroleum smelters. They are designed to withstand high temperatures and pressures.

Grades

The standard specifies different grades of steel for GB 9948 seamless steel pipes, such as 10#, 20#, 12CrMo, 15CrMo, and others. These grades have specific chemical compositions and mechanical properties to meet the requirements of petroleum cracking applications.

Manufacturing Process

GB 9948 seamless steel pipes are typically manufactured through processes such as hot rolling or cold drawing. These processes ensure the pipes have precise dimensions, smooth surfaces, and good mechanical properties.

Availability

GB 9948 seamless steel pipes are available from manufacturers and suppliers in China. They come in different sizes, grades, and specifications to meet specific project requirements.

GB 9948 is a Chinese standard that specifies the technical requirements for seamless steel tubes used in petroleum cracking. It covers various grades of steel, including 10#, 20#, 12CrMo, 15CrMo, and more.

Chemical Component(%) of GB 9948

Gade C Si Mn P S Cr Mo Ni
10 0.07-0.14 0.17-0.37 0.35-0.65 ≤0.035 ≤0.035 ≤0.15 / ≤0.25
20 0.17-0.24 0.17-0.37 0.35-0.65 ≤0.035 ≤0.035 ≤0.25 / ≤0.25
15CrMo 0.12-0.18 0.17-0.37 0.40-0.70 ≤0.035 ≤0.035 0.80-1.10 0.40-0.55 ≤0.30
1Cr2Mo ≤0.15 0.50-1.00 0.30-0.60 ≤0.035 ≤0.030 2.15-2.85 0.45-0.65 /
1Cr5Mo ≤0.15 ≤0.50 ≤0.60 ≤0.035 ≤0.030 4.00-6.00 0.45-0.60 ≤0.60

General GB 9948 seamless steel pipe use temperature below 450 ° C, domestic pipe is mainly made of 10, 20 carbon steel hot-rolled pipe or cold drawn pipe.

Mechanical Properties of GB 9948

Gade tensile strength (MPa) yield strength (MPa) elongation (%) impact energy (J) Brinell hardness (HB) delivery status
10 330-490 ≥205 ≥24 / / Normalizing
20 410-550 ≥245 ≥21 ≥39 / Normalizing
15CrMo 440-640 ≥235 ≥21 ≥47 ≤170 Normalizing + tempering
1Cr2Mo ≥390 ≥175 ≥22 ≥92 ≤179 Normalizing + tempering
1Cr5Mo ≥390 ≥195 ≥22 ≥92 ≤187 annealing

Additional Condition

Standard Standard
GB steel pipe

GB Steel pipe execution standard

GB seamless steel pipes are available from various manufacturers and suppliers in China. They come in different sizes, grades, and surface finishes to meet specific project requirements.

According to incomplete statistics, there are more than 240 national standard steel pipe production enterprises and more than 250 seamless steel pipe units.

  1. GB/T8162-1999 (Seamless steel pipe for structure). Mainly used for general structure and mechanical structure. Its representative material (brand): carbon steel 20, 45 steel; alloy steel Q345, 20Cr, 40Cr, 20CrMo, 30-35CrMo, 42CrMo, etc.
  2. GB/T8163-1999 (Seamless steel pipe for fluid conveying). Mainly used in engineering and large equipment to transport fluid pipelines. The representative material (brand) is 20, Q345, etc.
  3. GB3087-1999 (Seamless steel pipes for low and medium pressure boilers). Mainly used in industrial boilers and domestic boilers to transport low and medium pressure fluid pipelines. Representative materials are 10 and 20 steel.
  4. GB5310-1995 (Seamless steel pipes for high-pressure boilers). Mainly used for high temperature and high pressure transmission fluid headers and pipelines in power stations and nuclear power plants Representative materials are 20G, 12Cr1MoVG, 15CrMoG, etc.
  5. GB5312-1999 (Carbon steel and carbon manganese steel seamless steel pipe for ships). Mainly used for I and II pressure pipes for marine boilers and superheaters. Representative materials are 360, 410, 460 steel grades, etc.
  6. GB1479-2000 (Seamless steel tubes for high-pressure fertilizer equipment). Mainly used for conveying high temperature and high pressure fluid pipelines on fertilizer equipment. Representative materials are 20, 16Mn, 12CrMo, 12Cr2Mo, etc.
  7. GB9948-1988 (Seamless steel pipe for petroleum cracking). Mainly used in boilers, heat exchangers and fluid pipelines of petroleum smelters. Its representative materials are 20, 12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc.
  8. GB18248-2000 (Seamless steel pipe for gas cylinders). Mainly used to make various gas and hydraulic cylinders. Its representative materials are 37Mn, 34Mn2V, 35CrMo, etc.
  9. GB/T17396-1998 (Hot-rolled seamless steel pipe for hydraulic props). Mainly used to make coal mine hydraulic supports, cylinders and columns, and other hydraulic cylinders and columns. Its representative materials are 20, 45, 27SiMn, etc.
  10. GB3093-1986 (High-pressure seamless steel pipe for diesel engine). Mainly used for high pressure oil pipe of diesel engine injection system. The steel pipe is generally cold drawn, and its representative material is 20A.
  11. GB/T3639-1983 (Cold drawn or cold rolled precision seamless steel tube). It is mainly used for steel pipes for mechanical structures and carbon pressure equipment, requiring high dimensional accuracy and good surface finish. Its representative materials are 20, 45 steel, etc.
  12. GB/T3094-1986 (Cold drawn seamless steel pipe special-shaped steel pipe). It is mainly used to make various structural parts and parts, and its materials are high-quality carbon structural steel and low-alloy structural steel.
  13. GB/T8713-1988 (Precision inner diameter seamless steel pipe for hydraulic and pneumatic cylinders). It is mainly used to make cold-drawn or cold-rolled seamless steel pipes with precise inner diameters for hydraulic and pneumatic cylinders. Its representative materials are 20, 45 steel, etc.
  14. GB3093-1986 (High-pressure seamless steel pipes for diesel engines). Mainly used for high pressure oil pipe of diesel engine injection system. The steel pipe is generally cold drawn, and its representative material is 20A.
  15. GB/T3639-1983 (Cold drawn or cold rolled precision seamless steel tube). It is mainly used for steel pipes for mechanical structures and carbon pressure equipment, requiring high dimensional accuracy and good surface finish. Its representative materials are 20, 45 steel, etc.
  16. GB/T3094-1986 (Cold drawn seamless steel pipe special-shaped steel pipe). It is mainly used to make various structural parts and parts, and its materials are high-quality carbon structural steel and low-alloy structural steel.
  17. GB/T8713-1988 (Precision inner diameter seamless steel pipe for hydraulic and pneumatic cylinders). It is mainly used to make cold-drawn or cold-rolled seamless steel pipes with precise inner diameters for hydraulic and pneumatic cylinders. Its representative materials are 20, 45 steel, etc.
  18. GB13296-1991 (Stainless steel seamless steel tubes for boilers and heat exchangers). Mainly used in boilers, superheaters, heat exchangers, condensers, catalytic tubes, etc. of chemical enterprises. Used high temperature, high pressure, corrosion resistant steel pipe. Its representative materials are 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.
  19. GB/T14975-1994 (Stainless steel seamless steel pipe for structure). It is mainly used for general structure (hotel and restaurant decoration) and mechanical structure of chemical enterprises, which are resistant to atmospheric and acid corrosion and have certain strength. Its representative materials are 0-3Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr18Ni12Mo2Ti, etc.
  20. GB/T14976-1994 (Stainless steel seamless steel pipe for fluid transportation). Mainly used for pipelines that transport corrosive media. Representative materials are 0Cr13, 0Cr18Ni9, 1Cr18Ni9Ti, 0Cr17Ni12Mo2, 0Cr18Ni12Mo2Ti, etc.
  21. YB/T5035-1993 (Seamless steel pipe for automobile axle casing). It is mainly used to make high-quality carbon structural steel and alloy structural steel hot-rolled seamless steel pipes for automobile half-axle sleeves and drive axle axle tubes. Its representative materials are 45, 45Mn2, 40Cr, 20CrNi3A, etc.

Chemistry constitute table of main product steel grade

Steel Grade Chemistry Constitute
C Si Mn Cr Ni Mo P S Ti Cu
Q195 0.06-0.12 ≤0.30 0.25-0.50 ≤0.3 ≤0.3 - ≤0.045 ≤0.050 - ≤0.30
Q235 0.14-0.22 ≤0.30 0.30-0.65 ≤0.3 ≤0.3 - ≤0.045 ≤0.050 - ≤0.30
Q345B ≤0.20 ≤0.55 1.00-1.60 - - - ≤0.040 ≤0.040 - -
10# 0.07-0.13 0.07-0.37 0.35-0.65 ≤0.15 ≤0.3 - ≤0.035 ≤0.035 - ≤0.25
20# 0.17-0.23 0.07-0.37 0.35-0.65 ≤0.25 ≤0.3 - ≤0.035 ≤0.035 - ≤0.25
35# 0.32-0.39 0.07-0.37 0.50-0.80 ≤0.25 ≤0.3 - ≤0.035 ≤0.035 - ≤0.25
45# 0.42-0.50 0.07-0.37 0.50-0.80 ≤0.25 ≤0.3 - ≤0.035 ≤0.035 - ≤0.25
20Cr 0.18-0.24 0.07-0.37 0.50-0.80 0.70-1.00 ≤0.3 - ≤0.035 ≤0.035 - ≤0.30
40Cr 0.37-0.44 0.07-0.37 0.50-0.80 0.80-1.10 ≤0.3 - ≤0.035 ≤0.035 - ≤0.30
20CrMo 0.17-0.24 0.07-0.37 0.40-0.70 0.80-1.10 ≤0.3 0.15-0.25 ≤0.035 ≤0.035 - ≤0.30
30CrMo 0.26-0.34 0.07-0.37 0.40-0.70 0.80-1.10 ≤0.3 0.15-0.25 ≤0.035 ≤0.035 - ≤0.30
35CrMo 0.32-0.40 0.07-0.37 0.40-0.70 0.80-1.10 ≤0.3 0.15-0.25 ≤0.035 ≤0.035 - ≤0.30
42CrMo 0.38-0.45 0.07-0.37 0.50-0.80 0.90-1.20 1.00-1.40 0.15-0.25 ≤0.035 ≤0.035 - ≤0.30
20CrMoTi 0.17-0.23 0.07-0.37 0.40-0.70 0.45-0.75 ≤0.3 - ≤0.035 ≤0.035 - ≤0.30
35Mn2 0.32-0.39 0.07-0.37 1.40-1.80 ≤0.3 ≤0.3 - ≤0.035 ≤0.035 - ≤0.30
40Mn2 0.37-0.44 0.07-0.37 1.40-1.80 ≤0.3 ≤0.3 - ≤0.035 ≤0.035 - ≤0.30
35SiMn 0.32-0.40 1.10-1.40 1.10-1.40 ≤0.3 ≤0.3 - ≤0.035 ≤0.035 - ≤0.30
15Mn 0.12-0.16 0.07-0.37 0.70-1.00 ≤0.25 ≤0.3 - ≤0.035 ≤0.035 - ≤0.25
20Mn 0.17-0.23 0.07-0.37 0.70-1.00 ≤0.25 ≤0.3 - ≤0.035 ≤0.035 - ≤0.25

GB steel pipe size and tolerance

Deviation level Standardized outer diameter tolerance
D1 ±1.5%,min ±0.75 mm
D2 ±1.0%。min ±0.50 mm
D3 ±0.75%.min±0.30 mm
D4 ±0.50%。min ±0.10 mm
application

Application

Alloy steel pipes are ideally suitable for chemical, petrochemicals, and other energy-related applications.

The alloy steel pipe adopts high quality carbon steel, alloy structural steel and stainless & heat resisting steel as raw material through hot rolling or cold drawn to be made.

Alloy steel can be used in process area where carbon steel has limitation such as

As an important element of steel products, alloy steel pipe can be divided into seamless steel pipe and welded steel pipe according to the manufacturing technique and tube billet shape.

Here you can see the common alloy steel grade that you will come across.

Why the application of alloy steel pipe is wider than others

There are many kinds of materials used for transport in industrial production. Specifically we will have more choices and it is not limited to the use of alloy steel pipe. But even in the face of more choices, many people tend to choose alloy steel pipe. People make their own choices will have their own reasons. This means the alloy steel pipe application has its own advantages. Compared with transmission lines made of other materials, after it meets the basic application requirements, its quantity is lighter. Then in the practical application of alloy steel pipe, it will have more advantages because of this. Besides its physical characteristic advantage, it also has economic advantages. The wide application of alloy steel pipe is with kinds of reasons. So in practical usage, we can exploit the advantages to the full, in this way can we get more profits in these applications of alloy steel pipe.

What requirements should alloy steel pipe application meet

The transportation of kinds of gases or liquids in production needs to rely on alloy steel pipe. This shows that the actual role of alloy steel pipe application is important. High temperature resistant and low temperature resistant is the tolerance of temperature. In the practical application of alloy steel pipe, there will be many materials need to be transported. However their temperatures are not the same. So this can be the basic requirement to alloy steel pipe. It needs more corrosion resistance. Corrosion resistant material is the best material during transporting, because it is corrosion resistant. So it can be used in more occasions. And it is definitely very convenient for users.

The biggest advantages of alloy steel pipe

Can be 100% recycled, environmentally friendly, energy-saving, resource conservation, national strategy, national policy to encourage the expansion of the field of application of high-pressure alloy pipe. Of alloy steel pipe total consumption accounted steel in the proportion is only half of the developed countries, to expand the field of use of the alloy steel pipe to provide a wider space for the development of the industry. The future needs of the average annual growth of China’s high-pressure alloy steel pipe long products up to 10-12%.

Specification, standard and identification of alloy steel pipes

Alloy Steel pipe contains substantial quantities of elements other than carbon such as nickel, chromium, silicon, manganese, tungsten, molybdenum, vanadium and limited amounts of other commonly accepted elements such as manganese, sulfur, silicon, and phosphorous.

Industries We Serve

Our team of experienced sales specialists proudly partners with gas and chemical processors, power generation plants, oil refineries, and related industries to offer piping components and value-added services.

The biggest advantages of alloy steel pipe can be 100% recycled, environmentally friendly, energy-saving, resource conservation, national strategy, national policy to encourage the expansion of the field of application of high-pressure alloy pipe. Of alloy tube total consumption accounted steel in the proportion is only half of the developed countries, to expand the field of use of the alloy tube to provide a wider space for the development of the industry. According to the Chinese Special Steel Association alloy pipe Branch Expert Group, the future needs of the average annual growth of China’s high-pressure alloy pipe long products up to 10-12%.

Inspection

Chemical composition inspection, mechanical properties test(tensile strength,yield strength, elongation, flaring, flattening, bending, hardness, impact test), surface and dimension test,no-destructive test, hydrostatic test.

PMI

identification of the chemical composition of the metal used to manufacture the fitting. Uses PMI sensors, including X-ray fluorescence or optical emission spectrometry.

PMI
PMI
PMI
PMI
PMI
PMI

Size measurement

Size measurement
Size measurement
Size measurement
Size measurement
Size measurement

Seamless pipes with compound bevels as per ASME B16-25 And ASTM A333

ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe
ASTM A333 Grade 8 Seamless Pipe

Delivery

Steel pipe delivery status(condition)

Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).

Condition on delivery of steel pipe

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.

Steel strips bunding for fixed pipes

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.

Packing

Bare packing/bundle packing/crate packing/wooden protection at the both sides of tubes and suitably protected for sea-worthly delivery or as requested.

Packing
Packing
Packing
Packing
Packing
Packing

Placing steel pipes into containers

Packing
Packing
Packing
Packing
Packing
Packing

There are probably hundreds of different methods for packing a pipe, and most of them have merit, but there are two principles that are vital for any method to work prevent rusting and Sea transportation security.

Our packing can meet any needs of the customers.

FAQ FAQ

Our team of experienced sales specialists proudly partners with gas and chemical processors, power generation plants, oil refineries, and related industries to offer piping components and value-added services.

The most important and desired changes in alloy steel are

Alloy steels are made by combining carbon steel with one or several alloying elements, such as manganese, silicon, nickel, titanium, copper, chromium and aluminum. These metals are added to produce specific properties that are not found in regular carbon steel. The elements are added in varying proportions (or combinations) making the material take on different aspects such as increased hardness, increased corrosion resistance, increased strength, improved formability (ductility); the weldability can also change.

Alloying Elements & Their Effects

Pipes, Tubes and Hollow Sections

Norms

Grade

Alloying Elements

Commonly used alloying elements and their effects are listed in the table given below.

Alloying Elements Effect on the Properties
Chromium Increases Resistance to corrosion   and oxidation. Increases hardenability and wear resistance. Increases high   temperature strength.
Nickel Increases hardenability. Improves   toughness. Increases impact strength at low temperatures.
Molybdenum Increases hardenability, high   temperature hardness, and wear resistance. Enhances the effects of other   alloying elements. Eliminate temper brittleness in steels. Increases high   temperature strength.
Manganese Increases hardenability. Combines   with sulfur to reduce its adverse effects.
Vanadium Increases hardenability, high   temperature hardness, and wear resistance. Improves fatigue resistance.
Titanium Strongest carbide former. Added to   stainless steel to prevent precipitation of chromium carbide.
Silicon Removes oxygen in steel making.   Improves toughness. Increases hardness ability
Boron Increases hardenability. Produces   fine grain size.
Aluminum Forms nitride in nitriding steels.   Produces fine grain size in casting. Removes oxygen in steel melting.
Cobalt Increases heat and wear   resistance.
Tungsten Increases hardness at elevated   temperatures. Refines grain size.

【H】 Ceramic lined pipe

Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.

【H】 Cast basalt lined steel pipe

Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.

【H】 Ceramic Tile Lined Pipes

Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.

【H】 Rare earth alloy wear-resistant pipe

The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.

【H】 Tubes Erosion Shields

Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.

【H】 ASTM A213 T91 Alloy Tube

The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.