Introduction of ASTM A106 Seamless Pipe

This specification covers seamless carbon steel pipe for high-temperature service. These pipes are suitable for welding, bending, flanging, and similar forming operations. Mechanical testing of the specimens shall include tensile, bending, flattening, hydrostatic and nondestructive electric tests. Specimens undergoing bending tests shall consist of sections cut from a pipe. For flattening tests, the specimens shall be smooth on the ends and burr-free, except when made on crop ends. All tests shall be performed in room temperature. If any test specimen shows flaws it can be discarded and substituted for another test specimen. Before testing, if a specimen has scribe scratches, a retest shall be allowed. A retest shall also be allowed if a specimen breaks in an inside or outside surface flaw.

For ASTM A106 seamless steel pipe could transport fluids or gasses at high temperature and pressure levels, with 3 grades A, B, C, most common used ASTM A106 Grade B is widely used in the projects of oil and gas refineries, power plants, petrochemical plants, boilers.

ASTM A106 grade b seamless pipe

 ASTM A106 Gr B seamless pipes (also known as ASME SA106 GR B pipes) is a seamless carbon steel nominal pipe for high temperature use.

ASTM A106 grade C seamless pipes

ASTM A106 Gr C seamless pipes (also known as ASME SA106 GR C pipes) is a carbon-manganese steel pipe for high-temperature large-diameter boilers and superheaters. Its chemical composition is simple and similar to 20G carbon steel, but its carbon and manganese content is higher, so its yield strength is about 12% higher than that of 20G, and its plasticity and toughness are not bad. The steel has a simple production process and good cold and hot workability. Using it to replace 20G headers (economizer, water wall, low-temperature superheater and reheater header) can reduce the wall thickness by about 10%, which can save material costs, reduce welding workload, and improve headers The stress difference at start-up.

Mechanical properties of ASTM A106

Chemical requirements of ASTM A106 grade a, b and c

Manufacturing of ASTM A106 seamless pipe

The production process of A106 seamless pipe mainly includes the following steps:

1. Raw material preparation

Select high-quality carbon steel plate as raw material and cut it into appropriate size according to material requirements.

2. Heating treatment

After pickling, heat treatment and other processes, the steel plate is heated to an appropriate temperature to remove internal stress and physical impurities.

3. Perforation

Put the heated steel plate into the perforator and perforate it by rotating the drill bit to form the steel plate into a tube shape.

4. Hot rolling

The perforated tube billet is subjected to multiple hot rollings to gradually form it, and is continuously heated to an appropriate temperature to maintain a certain plasticity. At the same time, the wall thickness and outer diameter of the tube billet are controlled by rolling.

5. Final rolling

After hot rolling, it needs to be further processed by the final rolling mill to make the wall thickness and outer diameter of the tube billet more suitable to meet customer requirements.

6. Cutting

The seamless tube after final rolling is cut into standard lengths to form a finished product.

7. Testing

Non-destructive testing is performed on the finished products, including appearance inspection, dimension measurement, chemical composition analysis, mechanical properties testing and other links to ensure the quality of the products.

8. Surface treatment

The finished products are pickled, degreased, rusted and other treatments are performed to remove the protective agent and impurities on the surface of the steel pipe.

9. Packaging and storage

The treated finished products are packaged and then stored in a dry and ventilated warehouse waiting to be shipped out of the factory.

FAQ

1. Is there not much difference in performance between American standard seamless pipes and ordinary seamless pipes?

American standard seamless pipes implement ASTM A106 standard, which requires pipes to maintain good mechanical properties under high temperature conditions, including tensile strength, yield strength and elongation.

If ordinary seamless pipes are not produced strictly in accordance with this standard, they may not meet the requirements in terms of pressure resistance and temperature resistance.

2. Does the 5-12 mm wall thickness in the size specification affect the stable performance?

The ASTM A106 standard has clear tolerance requirements for wall thickness to ensure that the steel pipe is uniform within the specified thickness range, thereby ensuring the safe operation of the pipeline system. The specific wall thickness should be selected in combination with actual working conditions and design requirements.

3. Is the ASTM A106 standard only applicable to the oil and gas industry?

Although ASTM A106 seamless pipes are widely used in the field of oil and gas transportation, their scope of application is far more than that. Seamless pipes of this standard are also suitable for a variety of industrial pipeline systems such as power plants, boilers, papermaking and chemicals, especially where high temperature resistance is required.

4. Is the corrosion resistance of seamless pipes not as good as that of welded pipes?

Corrosion resistance mainly depends on the chemical composition of the steel and subsequent surface treatment. The control of carbon content and other element content specified in the ASTM A106 standard helps to improve the overall performance of steel, but it is not specifically designed for corrosion resistance.

If the pipeline application environment has high requirements for corrosion resistance, anti-corrosion coatings or alloy steel materials are usually used. Welded pipes are prone to weld defects at the joints. If anti-corrosion measures are not in place, corrosion problems are more likely to occur.