Details of GB/T9948 high-pressure seamless steel pipes commonly used in industrial energy projects

First, an introduction to GB/T9948 high-pressure seamless steel pipes

GB/T9948 high-pressure seamless steel pipes are seamless steel pipes for petroleum cracking (GB9948-88), which are furnace tubes, heat exchangers, and pipelines suitable for petroleum refineries. Mainly used for boilers, heat exchangers, and fluid delivery pipelines in petroleum refineries. Its representative materials are 20, 12CrMo, 1Cr5Mo, 1Cr19Ni11Nb, etc. GB9948 seamless steel pipes are mainly used to manufacture high-quality carbon structural steel, alloy structural steel, and stainless heat-resistant steel high-pressure seamless steel pipes for steam boiler steel pipes with high pressure and above.

Second, the material and performance requirements of GB/T9948 high-pressure seamless steel pipe

Material classification: GB/T9948 seamless steel pipe is mainly made of high-quality carbon structural steel (such as 20G, 20MnG, 25MnG), alloy structural steel (such as 15CrMoG, 12CrMoVG) and stainless heat-resistant steel (such as 1Cr18Ni9) and other materials to meet the high temperature and corrosion resistance requirements under different working conditions.

Key performance:

High endurance strength: Long-term work in high temperature and high pressure (such as above 450℃) environments requires creep resistance.

Oxidation resistance and corrosion resistance: Resist erosion by high-temperature flue gas, water vapor, and corrosive media.

Organization stability: Ensure uniform grain structure inside the steel pipe through heat treatment to avoid embrittlement or deformation after long-term use.

Third, the production and manufacturing methods and quality control of GB/T9948 high-pressure seamless steel pipes:

① Generally, the use temperature of 9948 seamless steel pipes is below 450℃, and domestic steel pipes are mainly made of No. 10 and No. 20 carbon steel hot-rolled pipes or cold-drawn pipes.

② 9948 seamless steel pipes are often in high temperature and high pressure conditions when used. Under the action of high-temperature flue gas and water vapor, the steel pipe will oxidize and corrode. The steel pipe is required to have high lasting strength, high anti-oxidation and corrosion performance, and good structural stability.

③ Quality control:

Hydraulic pressure test for each pipe: to ensure no leakage, the test pressure is usually 1.5 times the design pressure.

Physical performance test: including expansion test, flattening test, tensile test, and ultrasonic flaw detection to verify mechanical properties and internal defects.

Chemical composition inspection: According to the GB/T223 standard, the steel composition is tested to ensure that it meets the steel grade requirements.

Fourth, the use of GB/T9948 high-pressure seamless steel pipe:

① Boiler system: such as high-pressure steam pipes, superheater tubes, water-cooled wall tubes, etc.

② Petrochemical: used for cracking units, high-temperature and high-pressure reactors, and transportation pipelines.

③ Energy and electricity: high-temperature and high-pressure fluid transportation and nuclear power equipment in thermal power plants.