Production method of steel plate for 390MPa-grade wind power tower drum

Abstract

The invention discloses a production method of a steel plate for a 390MPa-grade wind power tower drum, and belongs to the technical field of metallurgical plate production. The production process comprises the following steps: smelting and continuous casting production process flow: KR desulfurization, converter treatment, LF refining, RH vacuum treatment, slab continuous casting and slow cooling; heating the plate blank in a furnace; the slab rolling comprises rough rolling and finish rolling; cooling the rolled steel plate; straightening the steel plate; the invention further discloses the mass percentage content of the chemical components of the steel plate. The steel plate for wind power is high in strength, good in forming performance, welding performance and fatigue performance and particularly excellent in low-temperature impact toughness, the low-temperature impact energy of the steel plate at the temperature of-60 DEG C is larger than or equal to 100 J, and the mechanical property and the technological property meet the technical requirements of users.

Description

Technical Field

[0001] The present invention belongs to the technical field of metallurgical sheet production, and particularly relates to a production method of a 390MPa grade steel plate for wind power tower tubes with excellent low-temperature impact performance at -60°C. Background Art

[0002] In the past three years, the average annual newly installed wind power capacity in China will be between 65 - 75GW, and it is estimated that the future demand for wind power tower tube steel plates in China will be about 4 - 5 million tons per year. The installation and application of wind power tower tubes are gradually expanding to harsh geological environments such as desert gobi and alpine regions. To ensure the safety of wind power tower tubes during service, while ensuring high strength, good formability, weldability, and fatigue performance of the steel for wind power, it is especially required to have excellent low-temperature impact toughness. The impact test temperature of the steel plate is reduced from -20 - -40°C to -60°C, greatly increasing the manufacturing difficulty of the steel plate. Against the background of energy conservation, environmental protection, and safety, the practical significance of improving the low-temperature impact toughness of 390MPa grade high-strength steel plates for wind power tower tubes is beyond doubt. The 390MPa grade steel plate for wind power tower tubes with excellent low-temperature impact performance at -60°C has good market prospects. Summary of the Invention

[0003] The purpose of the present invention is to provide a production method of a 390MPa grade steel plate for wind power tower tubes with excellent low-temperature impact performance at -60°C, and the thickness specification of the steel plate is 10.0mm - 50.0mm. The steel plate for wind power of the present invention has high strength, good formability, weldability, and fatigue performance, especially excellent low-temperature impact toughness. The low-temperature impact energy of the steel plate at -60°C ≥ 100J, and the mechanical properties and process properties meet the technical requirements of users.

[0004] To solve the above technical problems, the present invention adopts the following technical solutions:

[0005] A production method of a 390MPa grade steel plate for wind power tower tubes with excellent low-temperature impact performance at -60°C of the present invention includes:

[0006] The first step: the production process flow of smelting - continuous casting, KR desulfurization - converter - LF refining - RH vacuum treatment - slab continuous casting - slow cooling; wherein:

[0007] (1) After the pretreatment of hot metal, the S content ≤ 0.005%, and slag must be removed after desulfurization to ensure that the hot metal carries less slag;

[0008] (2) The converter uses self-produced high-quality scrap steel, minimizes the introduction of S, uses high-quality active lime, controls the basicity of the final slag at 3.0 - 3.5, adopts the bottom blowing argon mode of the converter, and the tapping temperature ≥ 1610°C;

[0009] (3) LF refining further deoxidizes, desulfurizes, removes inclusions, adjusts the composition and temperature;

[0010] (4) The RH refining mainly degasses the molten steel and makes inclusions float up, ensuring that the pure degassing time is greater than 5 minutes. After 20 minutes of vacuum treatment, the vacuum is broken by repressurization for calcium treatment. After the calcium treatment, the soft blowing time is ensured to be ≥ 10 min;

[0011] (5) The target superheat degree in the continuous casting process is 20 - 35 °C. The whole process is protected by pouring, and electromagnetic stirring and soft reduction are adopted. The casting speed is controlled at 0.9 - 1.1 m / min with constant casting speed control to ensure the quality of the cast slab. The cast slab is cooled slowly in a heat preservation pit, and the slow cooling time is ≥ 36 hours;

[0012] The second step: The slab is heated in the furnace; strictly control the residence time, soaking time and tapping temperature of the slab in the furnace. The residence time is ≥ 220 min, ensuring the soaking time is 40 - 60 min, and the tapping temperature is 1220 ± 20 °C;

[0013] The third step: The slab rolling includes rough rolling and finish rolling. After the billet is taken out of the furnace, it is quickly sent to a descaling machine to remove the scale. The rough rolling completes the width spreading with as few passes as possible. The rough rolling starting temperature is ≥ 1070 °C. After rough rolling, the slab is kept at a certain temperature, avoiding rolling in the partial recrystallization zone to prevent mixed grains. The finish rolling starting temperature is ≤ 930 °C, and the finish rolling final temperature is 780 ± 20 °C - 820 ± 20 °C;

[0014] The fourth step: The cooling mode of the rolled steel plate adopts laminar flow cooling based on the self - learning calculation results of the secondary system, and the final cooling temperature is 600 ± 20 °C - 640 ± 20 °C;

[0015] The fifth step: The steel plate is straightened according to the thickness specification of the steel plate and the actual shape of the cold - rolled steel plate;

[0016] The mass percentage content of the chemical components of the said steel plate is: C: 0.07 - 0.09%, Si: 0.20 - 0.30%, Mn: 1.45 - 1.55%, P: ≤ 0.010%, S ≤ 0.005%, Als: 0.020 - 0.040%, Nb: 0.035 - 0.045%, Ti: 0.010 - 0.020%, V: 0.035 - 0.045%, and the rest is Fe and inevitable impurities.

[0017] Furthermore, the mass percentage content of the chemical components of the said steel plate is: C: 0.08%, Si: 0.26%, Mn: 1.50%, P: 0.008%, S: 0.003%, Als: 0.027%, Nb: 0.040%, Ti: 0.015%, V: 0.035%, and the rest is Fe and inevitable impurities.

[0018] Further, the mass percentage of the chemical components of the steel plate is: C: 0.07%, Si: 0.25%, Mn: 1.51%, P: 0.009%, S: 0.002%, Als: 0.025%, Nb: 0.038%, Ti: 0.018%, V: 0.040%, and the balance is Fe and unavoidable impurities.

[0019] Further, the mass percentage of the chemical components of the steel plate is: C: 0.08%, Si: 0.25%, Mn: 1.49%, P: 0.008%, S: 0.002%, Als: 0.026%, Nb: 0.035%, Ti: 0.020%, V: 0.039%, and the balance is Fe and unavoidable impurities.

[0020] Further, the mass percentage of the chemical components of the steel plate is: C: 0.09%, Si: 0.29%, Mn: 1.55%, P: 0.010%, S: 0.002%, Als: 0.030%, Nb: 0.037%, Ti: 0.015%, V: 0.037%, and the balance is Fe and unavoidable impurities.

[0021] Further, the hot metal is subjected to desulfurization pretreatment, and the top-bottom combined blowing converter is used to smelt the hot metal to decarbonize and dephosphorize to obtain molten steel. Argon is blown throughout the converter smelting process, and scrap steel is added to the converter. The tapping temperature of the converter is 1643°C; then the molten steel after converter smelting is subjected to LF secondary refining, the in-position temperature of refining is ≥1565°C, and the molten steel after LF secondary refining is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min; slab continuous casting is carried out, the superheat is 27°C, and then slab cleaning, slow cooling, and continuous casting billet quality inspection are carried out; the slab heating temperature is 1225°C, the heating time is 238 min, the soaking time is 50 min, and the heated slab is subjected to high-pressure water descaling; after descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1185°C, and it is rolled to the thickness of the intermediate billet for temperature holding. The average starting temperature of finish rolling is 925°C, and the average final rolling temperature of finish rolling is 810°C, and the finished product thickness is 12.0 mm; after laminar flow cooling, the average temperature of the steel strip is reduced to 650°C, and then straightening is carried out; finally, sampling is carried out according to the standard for product quality inspection.

[0022] Furthermore, the hot metal is subjected to desulfurization pretreatment. The top-bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process. Scrap steel is added to the converter, and the tapping temperature of the converter is 1652 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining. The refining in-position temperature is ≥1554 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min. Slab continuous casting is carried out with a superheat of 28 °C. Then, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The heating temperature of the slab is 1235 °C, the heating time is 240 min, and the soaking time is 45 min. The heated slab is subjected to high-pressure water descaling. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1190 °C. The rough rolling is carried out until the intermediate slab thickness and then waiting for temperature equalization. The average starting temperature of finish rolling is 910 °C, and the average final rolling temperature of finish rolling is 800 °C. The finished product thickness is 26.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 635 °C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

[0023] Furthermore, the hot metal is subjected to desulfurization pretreatment. The top-bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process. Scrap steel is added to the converter, and the tapping temperature of the converter is 1661 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining. The refining in-position temperature is ≥1562 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min. Slab continuous casting is carried out with a superheat of 30 °C. Then, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The heating temperature of the slab is 1230 °C, the heating time is 250 min, and the soaking time is 50 min. The heated slab is subjected to high-pressure water descaling. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1177 °C. The rough rolling is carried out until the intermediate slab thickness and then waiting for temperature equalization. The average starting temperature of finish rolling is 900 °C, and the average final rolling temperature of finish rolling is 800 °C. The finished product thickness is 38.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 625 °C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

[0024] Furthermore, the hot metal is subjected to desulfurization pretreatment, and the top-bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process, and scrap steel is added to the converter. The tapping temperature of the converter is 1651°C. Then, the molten steel after converter smelting is subjected to LF secondary refining. The ladle furnace secondary refining in-position temperature is ≥1555°C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min. Slab continuous casting is carried out with a superheat of 28°C, and then slab cleaning, slow cooling, and continuous casting billet quality inspection are carried out. The slab heating temperature is 1225°C, the heating time is 241 min, and the soaking time is 60 min. The heated slab is subjected to high-pressure water descaling. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1195°C. It is rolled to the intermediate slab thickness and held for temperature equalization. The average finish rolling starting temperature is 890°C, and the average finish rolling final temperature is 790°C. The finished product thickness is 44.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 600°C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

[0025] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0026] The steel plate for wind power applications of the present invention has high strength, good formability, weldability, and fatigue performance. In particular, it has excellent low-temperature impact toughness. The low-temperature impact energy of the steel plate at -60°C is ≥100 J, and its mechanical properties and process performance meet the technical requirements of users. At the same time, the preparation method of the present invention is simple and suitable for industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described below in conjunction with the drawings.

[0028] Figure 1 It is the microstructural diagram of the hot-rolled steel plate of Example 3 of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] The present invention will be described in more detail below through specific embodiments. The embodiments are only descriptions of the best embodiments of the present invention and do not limit the scope of the present invention in any way.

[0030] Example 1

[0031] The hot metal is subjected to desulfurization pretreatment. The top-bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process. Scrap steel is added to the converter, and the tapping temperature of the converter is 1643 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining, and the refining in-position temperature is ≥1565 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min. Slab continuous casting is carried out according to the smelting chemical composition shown in Table 1, with a superheat of 27 °C. Then, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The slab heating temperature is 1225 °C, the heating time is 238 min, and the soaking time is 50 min. The heated slab is subjected to high-pressure water descaling. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1185 °C. When rolling to the thickness of the intermediate billet, it is held for temperature equalization. The average finish rolling starting temperature is 925 °C, and the average finish rolling ending temperature is 810 °C. The finished product thickness is 12.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 650 °C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

[0032] Example 2

[0033] The hot metal is subjected to desulfurization pretreatment. The top-bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process. Scrap steel is added to the converter, and the tapping temperature of the converter is 1652 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining, and the refining in-position temperature is ≥1554 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min. Slab continuous casting is carried out according to the smelting chemical composition shown in Table 1, with a superheat of 28 °C. Then, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The slab heating temperature is 1235 °C, the heating time is 240 min, and the soaking time is 45 min. The heated slab is subjected to high-pressure water descaling. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1190 °C. When rolling to the thickness of the intermediate billet, it is held for temperature equalization. The average finish rolling starting temperature is 910 °C, and the average finish rolling ending temperature is 800 °C. The finished product thickness is 26.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 635 °C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

[0034] Example 3

[0035] The hot metal is subjected to desulfurization pretreatment. The top-bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process. Scrap steel is added to the converter, and the tapping temperature of the converter is 1661 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining. The in-position temperature for refining is ≥1562 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min. Slab continuous casting is carried out according to the smelting chemical composition shown in Table 1, with a superheat of 30 °C. Then, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The heating temperature of the slab is 1230 °C, the heating time is 250 min, and the soaking time is 50 min. High-pressure water descaling is carried out on the heated slab. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1177 °C. When rolling to the thickness of the intermediate slab, it is held for temperature equalization. The average starting temperature of finish rolling is 900 °C, and the average final rolling temperature of finish rolling is 800 °C. The finished product thickness is 38.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 625 °C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

[0036] Example 4

[0037] The hot metal is subjected to desulfurization pretreatment. The top-bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process. Scrap steel is added to the converter, and the tapping temperature of the converter is 1651 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining. The in-position temperature for refining is ≥1555 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min. Slab continuous casting is carried out according to the smelting chemical composition shown in Table 1, with a superheat of 28 °C. Then, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The heating temperature of the slab is 1225 °C, the heating time is 241 min, and the soaking time is 60 min. High-pressure water descaling is carried out on the heated slab. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1195 °C. When rolling to the thickness of the intermediate slab, it is held for temperature equalization. The average starting temperature of finish rolling is 890 °C, and the average final rolling temperature of finish rolling is 790 °C. The finished product thickness is 44.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 600 °C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

[0038] Example 5

[0039] The hot metal is subjected to desulfurization pretreatment, and the top-bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process, and scrap steel is added to the converter. The tapping temperature of the converter is 1655 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining, and the in-position refining temperature is ≥1550 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min. Slab continuous casting is carried out according to the smelting chemical composition shown in Table 1, with a superheat of 26 °C. After that, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The slab heating temperature is 1230 °C, the heating time is 231 min, and the soaking time is 45 min. The heated slab is subjected to high-pressure water descaling. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1190 °C. After rolling to the thickness of the intermediate billet, it is held at temperature. The average starting temperature of finish rolling is 880 °C, and the average final rolling temperature of finish rolling is 780 °C. The finished product thickness is 50.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 590 °C, and then straightening is carried out. Finally, sampling is carried out according to the standard for product quality inspection.

[0040] The chemical compositions of the hot-rolled steel plates in Examples 1 to 5 of the present invention are shown in Table 1, and the measured values of their mechanical properties are shown in Table 2. It can be seen that the mechanical properties and process properties of the hot-rolled steel plates of the present invention meet the technical requirements of users.

[0041] Table 1 Chemical compositions (wt%) of Examples 1 to 5 of the present invention

[0042] Embodiment C Si Mn P S Als Nb Ti V 1 0.08 0.26 1.50 0.008 0.003 0.027 0.040 0.015 0.035 2 0.07 0.25 1.51 0.009 0.002 0.025 0.038 0.018 0.040 3 0.08 0.25 1.49 0.008 0.002 0.026 0.035 0.020 0.039 4 0.09 0.29 1.55 0.010 0.002 0.030 0.037 0.015 0.037 5 0.09 0.24 1.53 0.007 0.002 0.026 0.045 0.019 0.040

[0043] Table 2 Mechanical properties and process properties of Examples 1 to 5 of the present invention

[0044]

[0045]

[0046] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention shall fall within the protection scope determined by the claims of the present invention.

Claims

1. A production method of a steel plate for a 390 MPa wind power tower barrel, characterized in that, include: Step 1: Smelting-continuous casting production process, KR desulfurization-converter-LF refining-RH vacuum treatment-slab continuous casting-slow cooling; Among them: (1) The sulfur content of molten iron after pretreatment is ≤0.005%. Slag must be removed after desulfurization to ensure that the molten iron contains less slag; (2) The converter uses self-produced high-quality scrap steel, minimizes the introduction of sulfur, uses high-quality active lime, controls the final slag basicity at 3.0-3.5, uses argon blowing mode at the bottom of the converter, and the tapping temperature is ≥1610°C; (3) LF refining further deoxidizes, desulfurizes, removes impurities, and adjusts composition and temperature; (4) RH refining mainly degasses the molten steel and floats the inclusions, ensuring that the pure degassing time is greater than 5 minutes. After vacuum treatment for 20 minutes, the vacuum is broken again to perform calcium treatment. After the calcium treatment, the soft blowing time is ensured to be ≥10 minutes; (5) The target superheat of the continuous casting process is 20-35°C, the casting is protected throughout the process, electromagnetic stirring and light pressure are used, the pulling speed is controlled at 0.9-1.1m / min, constant pulling speed control is used to ensure the quality of the ingot, and the ingot is slowly cooled in the insulation pit, and the slow cooling time is ≥36 hours; Step 2: The slab is put into the furnace for heating; strictly control the slab’s time in the furnace, soaking time and out-of-furnace temperature, the time in the furnace is ≥220min, the soaking time is guaranteed to be 40-60min, and the out-of-furnace temperature is 1220±20℃; Step 3: Slab rolling includes rough rolling and finishing rolling. After the billet is taken out of the furnace, it is quickly sent to the descaling machine to remove the iron oxide scale. The rough rolling is completed with as few passes as possible. The starting temperature of the rough rolling is ≥1070℃. After the rough rolling, the slab is kept warm, avoiding the partial recrystallization zone and avoiding mixed crystals. The starting temperature of the finishing rolling is ≤930℃, and the finishing temperature of the finishing rolling is 780±20℃-820±20℃; Step 4: The cooling mode of the rolled steel plate adopts laminar cooling based on the self-learning calculation results of the secondary system, and the final cooling temperature is 600±20℃-640±20℃; Step 5: Straighten the steel plate according to the thickness specification of the steel plate and the actual shape of the steel plate after cooling; The chemical composition of the steel plate is in the following mass percentages: C: 0.07-0.09%, Si: 0.20-0.30%, Mn: 1.45-1.55%, P: ≤0.010%, S≤0.005%, Als: 0.020-0.040%, Nb: 0.035-0.045%, Ti: 0.010-0.020%, V: 0.035-0.045%, and the rest is Fe and unavoidable impurities.

2. The production method of the steel plate for 390MPa wind power tower barrel according to claim 1, characterized in that The mass percentage of the chemical composition of the steel plate is C: 0.08%, Si: 0.26%, Mn: 1.50%, P: 0.008%, S: 0.003%, Als: 0.027%, Nb: 0.040%, Ti: 0.015%, V: 0.035%, and the rest is Fe and unavoidable impurities.

3. The production method of the steel plate for 390 MPa wind power tower barrels according to claim 1, characterized in that, The mass percentage content of the chemical components of the steel plate is as follows: C: 0.07%, Si: 0.25%, Mn: 1.51%, P: 0.009%, S: 0.002%, Als: 0.025%, Nb: 0.038%, Ti: 0.018%, V: 0.040%, and the rest is Fe and inevitable impurities.

4. The production method of the steel plate for 390 MPa wind power tower barrels according to claim 1, characterized in that, The mass percentage content of the chemical components of the steel plate is as follows: C: 0.08%, Si: 0.25%, Mn: 1.49%, P: 0.008%, S: 0.002%, Als: 0.026%, Nb: 0.035%, Ti: 0.020%, V: 0.039%, and the rest is Fe and inevitable impurities.

5. The production method of the steel plate for 390 MPa wind power tower barrels according to claim 1, characterized in that, The mass percentage content of the chemical components of the steel plate is as follows: C: 0.09%, Si: 0.29%, Mn: 1.55%, P: 0.010%, S: 0.002%, Als: 0.030%, Nb: 0.037%, Ti: 0.015%, V: 0.037%, and the rest is Fe and inevitable impurities.

6. The production method of the steel plate for 390MPa wind power tower barrel according to claim 2, characterized in that, The hot metal is subjected to desulfurization pretreatment, and top-bottom combined blowing converter smelting is used to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process, and scrap steel is added to the converter. The tapping temperature of the converter is 1643°C; then the molten steel after converter smelting is subjected to LF secondary refining, and the in-position temperature for refining is ≥1565°C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min; slab continuous casting is carried out with a superheat of 27°C, and then slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out; the heating temperature of the slab is 1225°C, the heating time is 238 min, and the soaking time is 50 min. The heated slab is subjected to high-pressure water descaling; after descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1185°C, and it is rolled to the thickness of the intermediate billet for temperature holding. The average starting temperature for finish rolling is 925°C, and the average final rolling temperature for finish rolling is 810°C. The finished thickness is 12.0 mm; after laminar cooling, the average temperature of the steel strip is reduced to 650°C, and then straightening is carried out; finally, samples are taken according to the standard for product quality inspection.

7. The production method of the 390 MPa wind power tower barrel steel plate according to claim 3, characterized in that, The hot metal is subjected to desulfurization pretreatment. The top and bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process. Scrap steel is added to the converter, and the tapping temperature of the converter is 1652 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining. The refining in-position temperature is ≥1554 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the holding vacuum time is ≥10 min. Slab continuous casting is carried out with a superheat of 28 °C. Then, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The heating temperature of the slab is 1235 °C, the heating time is 240 min, and the soaking time is 45 min. The heated slab is subjected to high-pressure water descaling. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1190 °C. When rolling to the thickness of the intermediate billet, it is held for temperature equalization. The average finish rolling starting temperature is 910 °C, and the average finish rolling ending temperature is 800 °C. The finished product thickness is 26.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 635 °C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

8. The production method of the steel plate for 390 MPa wind power tower barrels according to claim 4, characterized in that, The hot metal is subjected to desulfurization pretreatment. The top and bottom combined blowing converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process. Scrap steel is added to the converter, and the tapping temperature of the converter is 1661 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining. The refining in-position temperature is ≥1562 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the holding vacuum time is ≥10 min. Slab continuous casting is carried out with a superheat of 30 °C. Then, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The heating temperature of the slab is 1230 °C, the heating time is 250 min, and the soaking time is 50 min. The heated slab is subjected to high-pressure water descaling. After descaling, rolling is carried out. Both rough rolling and finish rolling use two-high reversing mills. The rough rolling starting temperature is 1177 °C. When rolling to the thickness of the intermediate billet, it is held for temperature equalization. The average finish rolling starting temperature is 900 °C, and the average finish rolling ending temperature is 800 °C. The finished product thickness is 38.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 625 °C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

9. The production method of the steel plate for 390 MPa wind power tower barrels according to claim 5, characterized in that The hot metal is subjected to desulfurization pretreatment. The top-bottom combined blown converter is used for smelting to decarbonize and dephosphorize the hot metal to obtain molten steel. Argon is blown throughout the converter smelting process. Scrap steel is added to the converter, and the tapping temperature of the converter is 1651 °C. Then, the molten steel after converter smelting is subjected to LF secondary refining, and the in-position temperature for refining is ≥1555 °C. After LF secondary refining, the molten steel is subjected to RH vacuum treatment, and the vacuum holding time is ≥10 min. Slab continuous casting is carried out with a superheat of 28 °C. After that, slab cleaning, slow cooling, and quality inspection of the continuous casting billet are carried out. The heating temperature of the slab is 1225 °C, the heating time is 241 min, and the soaking time is 60 min. The heated slab is subjected to high-pressure water descaling. After descaling, rolling is carried out. Both rough rolling and finish rolling use 2-high reversing mills. The rough rolling starting temperature is 1195 °C. After rolling to the thickness of the intermediate billet, it is kept at temperature. The average starting temperature for finish rolling is 890 °C, and the average final rolling temperature for finish rolling is 790 °C. The finished product thickness is 44.0 mm. After laminar cooling, the average temperature of the steel strip is reduced to 600 °C, and then straightening is carried out. Finally, samples are taken according to the standard for product quality inspection.

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