15CrMoG
Chromium molybdenum alloy steel pipe designed for high-temperature and high-strength applications.
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.
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.
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.
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.
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.
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.
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.
| 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.
| 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 |
GB seamless steel pipes are widely produced in China, available in various sizes, grades and surface finishes to meet specific project requirements.
According to industry statistics, there are more than 240 national standard steel pipe manufacturers and 250 seamless steel pipe production lines in China.
| Grade | 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 |
| 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 |
| Class | 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 |
With years of expertise, we provide a wide range of steel tube processing services. From basic sawing and machining to complex bending and upsetting operations, we support you at every stage of your project.
Our capabilities include eccentricity reduction and concentricity improvement through turning and grinding. We specialize in creating complex geometries using rotary swaging and axial forming, and offer property modifications through partial heat treatment to meet your exact requirements.
A range to meet your needs
High-quality steel solutions for diverse mechanical engineering applications – reliable, precise, and built for performance.
Premium steel products for demanding construction projects – from bridges to offshore structures, built to last.
Versatile components for the automotive industry – precision, quality, and processing expertise for every application.
Robust tubes for plant engineering and energy systems – designed for extreme conditions and long-term efficiency.
Versatile solutions for modern infrastructure – supporting reliable supply networks and large-scale construction projects.
Versatile solutions for hydraulic systems – durable, pressure-resistant, and engineered for maximum reliability.
| Condition | Typical Application |
|---|---|
| High Temperature | Boilers, superheaters, steam headers |
| Low Temperature | Cryogenic processing systems |
| High Pressure | Power & process piping |
| Corrosive Media | Chemical & petrochemical plants |
| Creep Service | Thermal power stations |
| Product | Specification |
|---|---|
| Seamless Pipes | ASTM A335 P1 / P5 / P9 / P11 / P22 / P91 |
| Butt Weld Fittings | ASTM A234 WP1 / WP5 / WP9 / WP11 / WP22 / WP91 |
| Forged Fittings & Flanges | ASTM A182 F1 / F5 / F9 / F11 / F22 / F91 |
Sunny Steel supplies alloy steel piping systems worldwide, supporting projects that demand certified materials, full traceability and long-term operational reliability.
Chemical composition inspection, mechanical properties test(tensile strength,yield strength, elongation, flaring, flattening, bending, hardness, impact test), surface and dimension test, non-destructive test, hydrostatic test.
Identification of the chemical composition of the metal used to manufacture the fitting. Uses PMI sensors, including X-ray fluorescence or optical emission spectrometry.
Steel pipe delivery status(condition): cold / hard (BK), cold / soft (BKW), after cold stress relief annealing (BKS), annealing (GBK), normalized (NBK).
| 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.
Bare packing/bundle packing/crate packing/wooden protection at the both sides of tubes and suitably protected for seaworthy delivery or as requested.
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.
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. |
Ceramic lined pipe is made through self-propagating high-temperature synthesis (SHS) technique.
Cast basalt lined steel pipe is composed by lined with cast basalt pipe, outside steel pipe and cement mortar filling between the two layers.
Ceramic tile lined pipes have very uniform coating of specially formulated ceramic material that is affixed to the inner of the pipe.
The material of the rare earth alloy wear-resistant pipe is ZG40CrMnMoNiSiRe, which is also the grade of rare earth alloy steel.
Tubes Erosion Shields are used to protect boiler tubing from the highly erosive effects of high temperatures and pressures thereby greatly extending tube life.
The ASTM A213 T91 seamless tubes are primarily used for boiler, superheater, and heat-exchanger.
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