A heat treatment method for L290QH hydrogen transport pipeline pipe

Abstract

The application discloses a heat treatment method of L290QH hydrogen conveying pipeline pipe, which comprises the following steps: controlling the carbon equivalent CE of the steel to be ≤0.19 PCM ; loading the seamless steel pipe into a quenching furnace, heating the seamless steel pipe to 910 DEG C in the heat preservation section, and keeping the temperature for 5 minutes; taking the seamless steel pipe out of the quenching furnace for water quenching heat treatment, spraying water at the nozzle in the head end of the steel pipe at a flow rate of 1900 m 3 / h, spraying water at the outer spraying pipe at a flow rate of 3200 m 3 / h, starting the inner water spraying after 3 seconds of starting the outer water spraying, spraying water for 40 seconds in the outer spraying and the inner spraying, rotating the radial wheel at a speed of 40 r / min, and cooling the seamless steel pipe to below 100 DEG C; heating the seamless steel pipe to 660 DEG C for soaking and heat preservation, controlling the total time from heating to heat preservation to be 140 minutes, and controlling the furnace temperature to be ±10 DEG C; and taking the seamless steel pipe out of the furnace for air cooling after the tempering heat treatment of the seamless steel pipe is completed. The steel pipe has excellent performances.

Description

Technical Field

[0001] This invention relates to the fields of ferrous metal smelting and metal pressure processing, and particularly to a heat treatment method for an L290QH hydrogen pipeline. Background Technology

[0002] Hydrogen is considered one of the most important energy sources for widespread use in the 21st century, boasting advantages such as abundant reserves, high heat output from combustion, diverse manufacturing methods, high economic efficiency, and environmentally friendly combustion products. Currently, with finite fossil fuel resources gradually dwindling, the advantages of hydrogen energy are becoming increasingly prominent. Considering all factors, hydrogen energy possesses enormous application potential and can provide crucial support for the sustainable development of human society. However, current hydrogen transportation pipelines utilize low-strength pipeline steel to prevent hydrogen embrittlement.

[0003] Hydrogen energy, as an energy carrier, can effectively mitigate the greenhouse effect and ensure energy supply. Currently, there are approximately 3000 km of hydrogen pipelines worldwide, with a maximum service pressure of 10 MPa, mainly supplying hydrogen to the chemical or petroleum industries. The steel grade of these pipelines typically does not exceed X52. This invention aims to provide a heat treatment method for L290QH hydrogen pipeline pipes. Summary of the Invention

[0004] The purpose of this invention is to provide a heat treatment method for L290QH hydrogen pipeline pipes, resulting in steel pipes with excellent performance.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention discloses a heat treatment method for an L290QH hydrogen pipeline, comprising:

[0007] 1) Hot-rolled L290QH seamless steel pipes for pipelines with qualified dimensional accuracy and surface quality ensure that the carbon equivalent CE in the steel is within acceptable limits. PCM ≤0.19;

[0008] 2) The seamless steel pipe is loaded into the quenching furnace. After passing through the heating section and the heat preservation section, the temperature of the seamless steel pipe in the heat preservation section is heated to 910℃ and held for 5 minutes.

[0009] 3) Seamless steel pipes undergo water quenching heat treatment after exiting the quenching furnace. The water spray volume of the nozzle inside the pipe end is 1900m³. 3 / h, the external water spraying capacity of the external spray pipe is 3200m³ / h. 3 / h, the external water spray starts 3 seconds after the internal water spray starts, and both the external and internal spray last for 40 seconds. The radial wheel speed is 40 revolutions / minute, cooling the seamless steel pipe to below 100℃;

[0010] 4) Heat the seamless steel pipe to 660℃ for homogenization and heat preservation. The total time from heating to heat preservation should be controlled within 140 minutes, and the furnace temperature should be controlled within ±10℃.

[0011] 5) After the seamless steel pipe has undergone tempering heat treatment, it is air-cooled after being taken out of the furnace;

[0012] 6) Take 300mm samples from both ends of the heat-treated seamless steel pipe for mechanical property and microstructure analysis. If the chemical composition and mechanical properties are qualified, it is a finished L290QH seamless steel pipe for pipelines.

[0013] Furthermore, the hot-rolled L290QH pipeline seamless steel pipe is a hot-rolled seamless steel pipe with an outer diameter of 273.1mm and a wall thickness of 7.1mm.

[0014] Furthermore, it comprises the following chemical composition by mass percentage: C 0.07-0.11%, Si 0.30-0.4%, Mn 1.15-1.35%, P ≤0.010%, S ≤0.003%, Ti 0.01-0.02%, with the remainder being Fe and unavoidable impurities.

[0015] Furthermore, the performance indicators of the L290QH hydrogen pipeline are as follows:

[0016] Yield strength: 330MPa~370MPa; Tensile strength: 455MPa~520MPa; Yield-to-tensile ratio: ≤0.81; Elongation: ≥30%; Transverse impact value at -20℃: AKV≥150J / cm 2 Grain size: ≥9.0 grade.

[0017] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0018] An economical L290QH seamless steel pipe for hydrogen pipelines is produced using a combination of C+Mn+Ti alloying elements. This steel pipe undergoes water quenching and tempering heat treatment, resulting in excellent performance characteristics. Specific performance indicators are as follows:

[0019] Yield strength: 330MPa~370MPa; Tensile strength: 455MPa~520MPa; Yield-to-tensile ratio: ≤0.81; Elongation: ≥30%; Transverse impact value at -20℃: AKV≥150J / cm 2 Grain size: ≥9.0 grade.

[0020] This invention addresses the problems existing in the background technology by employing technical measures such as "economical chemical composition design and unique heat-generating treatment production process," effectively solving the aforementioned technical problems and achieving significant progress. Attached Figure Description

[0021] The present invention will be further described below with reference to the accompanying drawings.

[0022] Figure 1 This is a microscopic tissue diagram of Example 1;

[0023] Figure 2 This is a microscopic tissue diagram of Example 2;

[0024] Figure 3 This is a microstructure diagram of Example 3. Detailed Implementation

[0025] A heat treatment method for L290QH hydrogen pipeline pipe: Hot-rolled seamless steel pipe with an outer diameter of 273.1mm and a wall thickness of 7.1mm, whose specified chemical composition range (mass fraction) is shown in Table 1, is loaded into a quenching furnace. After passing through a heating section and a holding section, the temperature of the seamless steel pipe in the holding section is heated to 910℃ and held for 5 minutes. The steel pipe is then removed from the quenching furnace for quenching heat treatment. The cooling medium is water, with an internal water spray volume of 1900m³. 3 / h, external water spray volume 3200m 3 The cooling time was 40 seconds, and the radial wheel speed was 40 revolutions per minute, cooling the test steel pipe to below 100℃. The quenched steel pipe was then placed in a tempering furnace for tempering heat treatment. The tempering furnace included a heating section, a soaking section, and a holding section. The seamless steel pipe was heated to 660℃ for soaking and holding. The total time from heating to holding was controlled at 140 minutes, with the furnace temperature controlled within ±10℃. After tempering heat treatment, the seamless steel pipe was removed from the furnace and air-cooled. 300mm samples were taken from both ends of the heat-treated seamless steel pipe for mechanical property and microstructure analysis. Seamless steel pipes with qualified chemical composition and mechanical properties were considered finished L290QH pipeline seamless steel pipes.

[0026] Table 1 Chemical composition of L290QH pipeline pipe, Wt.%

[0027]

[0028] The process flow can be briefly described as follows: hot-rolled seamless steel pipe → quenching furnace heating → quenching furnace heat preservation → unloading → water quenching → tempering furnace heating → tempering furnace homogenization → tempering furnace heat preservation → unloading → air cooling → sampling at the head and tail ends → testing and analysis.

[0029] The production process of heat treatment for hot-rolled seamless steel pipes with an outer diameter of 273.1mm and a wall thickness of 7.1mm is as follows:

[0030] 1. Hot-rolled L290QH seamless steel pipes for pipelines with qualified dimensional accuracy and surface quality ensure a high carbon equivalent (CE) in the steel. PCM ≤0.19.

[0031] 2. The seamless steel pipe is loaded into the quenching furnace. After passing through the heating section and the heat preservation section, the temperature of the seamless steel pipe in the heat preservation section is heated to 910℃ and held for 5 minutes.

[0032] 3. Seamless steel pipes undergo water quenching heat treatment after exiting the quenching furnace. The water spray volume from the nozzle inside the pipe end is 1900 ml. 3 / h, the external water spraying capacity of the external spray pipe is 3200m³ / h. 3 / h, the external water spray starts 3 seconds after the internal water spray starts, and both the external and internal spray last for 40 seconds. The radial wheel speed is 40 revolutions per minute, which cools the seamless steel pipe to below 100℃;

[0033] 4. Heat the seamless steel pipe to 660℃ for homogenization and heat preservation. The total time from heating to heat preservation should be controlled within 140 minutes, and the furnace temperature should be controlled within ±10℃.

[0034] 5. After the seamless steel pipe has undergone tempering heat treatment, it is air-cooled after being taken out of the furnace.

[0035] 6. Take 300mm samples from both ends of the heat-treated seamless steel pipe for mechanical property and microstructure analysis. If the chemical composition and mechanical properties meet the requirements, it is considered a finished L290QH seamless steel pipe for pipeline use.

[0036] After the above heat treatment process, the "L290QH seamless steel pipe for hydrogen pipeline" described in this invention can be produced.

[0037] The present invention will be further described in detail below with reference to Examples 1 to 3.

[0038] The hot-rolled L290QH seamless steel pipe for hydrogen pipelines, with its dimensional accuracy and surface quality meeting standards, ensures a high carbon equivalent (CE) content in the steel. PCM ≤0.19.

[0039] The production process sequence is as follows: hot-rolled seamless steel pipe → quenching furnace heating → quenching furnace heat preservation → unloading → water quenching → tempering furnace heating → tempering furnace homogenization → tempering furnace heat preservation → unloading → air cooling → sampling at the head and tail ends → testing and analysis.

[0040] The specific production process is briefly described below:

[0041] 1. Hot-rolled L290QH seamless steel pipes for hydrogen pipelines with qualified dimensional accuracy and surface quality ensure a high carbon equivalent (CE) content in the steel. PCM ≤0.19.

[0042] 2. The seamless steel pipe is loaded into the quenching furnace. After passing through the heating section and the heat preservation section, the temperature of the seamless steel pipe in the heat preservation section is heated to 910℃ and held for 5 minutes.

[0043] 3. Seamless steel pipes undergo water quenching heat treatment after exiting the quenching furnace. The water spray volume of the nozzle inside the pipe end is 1900 ml.3 / h, the external water spraying capacity of the external spray pipe is 3200m³ / h. 3 / h, the external water spray starts 3 seconds after the internal water spray starts, and both the external and internal spray last for 40 seconds. The radial wheel speed is 40 revolutions per minute, which cools the seamless steel pipe to below 100℃.

[0044] 4. Heat the seamless steel pipe to 660℃ for homogenization and heat preservation. The total time from heating to heat preservation should be controlled within 140 minutes, and the furnace temperature should be controlled within ±10℃.

[0045] 5. After the seamless steel pipe has undergone tempering heat treatment, it is air-cooled after being taken out of the furnace.

[0046] 6. Take 300mm samples from both ends of the heat-treated seamless steel pipe for mechanical property and microstructure analysis.

[0047] After heat treatment, samples of L290QH seamless steel pipes for hydrogen pipelines with specifications of Ф273.1mm×7.1mm×12000mm (outer diameter of steel pipe × wall thickness of steel pipe × length of steel pipe) were taken for chemical testing. The chemical composition test results (weight percentage content) are shown in Table 2, the mechanical property test results are shown in Table 3, the metallographic property test results are shown in Table 4, and the microstructure photographs are shown in Table 5. Figures 1-3 As shown.

[0048] Table 2. Chemical composition test results of the tube blank (wt%)

[0049] Example 1 0.08 0.30 1.20 0.005 0.002 0.011 0.15 Example 2 0.09 0.31 1.19 0.006 0.003 0.012 0.16 Example 3 0.09 0.30 1.21 0.007 0.002 0.014 0.16

[0050] Table 3. Mechanical property test results of seamless steel pipes

[0051] Example 1 345 485 0.81 43 180，178，185 Example 2 351 490 0.80 41 191，183，186 Example 3 349 484 0.80 42 190，187，191

[0052] Table 4. Metallographic Performance Test Results of Seamless Steel Pipes (Grade)

[0053]

[0054] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A heat treatment method for an L290QH hydrogen pipeline, characterized in that, include: 1) Hot-rolled L290QH seamless steel pipes for pipelines with qualified dimensional accuracy and surface quality ensure that the carbon equivalent CE in the steel is within acceptable limits. PCM ≤0.19; 2) The seamless steel pipe is loaded into the quenching furnace. After passing through the heating section and the heat preservation section, the temperature of the seamless steel pipe in the heat preservation section is heated to 910℃ and held for 5 minutes. 3) Seamless steel pipes undergo water quenching heat treatment after exiting the quenching furnace. The water spray volume of the nozzle inside the pipe end is 1900m³. 3 / h, the external water spraying capacity of the external spray pipe is 3200m³ / h. 3 / h, the external water spray starts 3 seconds after the internal water spray starts, and both the external and internal spray last for 40 seconds. The radial wheel speed is 40 revolutions / minute, cooling the seamless steel pipe to below 100℃; 4) Heat the seamless steel pipe to 660℃ for homogenization and heat preservation. The total time from heating to heat preservation should be controlled within 140 minutes, and the furnace temperature should be controlled within ±10℃. 5) After the seamless steel pipe has undergone tempering heat treatment, it is air-cooled after being taken out of the furnace; 6) Take 300mm samples from both ends of the heat-treated seamless steel pipe for mechanical property and microstructure analysis. If the chemical composition and mechanical properties are qualified, it is the finished product of L290QH seamless steel pipe for pipeline. It comprises the following chemical composition by mass percentage: C 0.07-0.11%, Si 0.30-0.4%, Mn 1.15-1.35%, P≤0.010%, S≤0.003%, Ti 0.01-0.02%, with the remainder being Fe and unavoidable impurities.

2. The heat treatment method for the L290QH hydrogen pipeline according to claim 1, characterized in that, The hot-rolled L290QH pipeline seamless steel pipe is a hot-rolled seamless steel pipe with an outer diameter of 273.1mm and a wall thickness of 7.1mm.

3. The heat treatment method for the L290QH hydrogen pipeline according to claim 1, characterized in that, The performance specifications of the L290QH hydrogen pipeline are as follows: Yield strength: 330MPa~370MPa; Tensile strength: 455MPa~520MPa; Yield-to-tensile ratio: ≤0.81; Elongation: ≥30%; Transverse impact value at -20℃: AKV ≥150J / cm 2 ; Grain size: ≥9.0 grade.

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