A 09MnNiDR thick plate resistant to hydrogen-induced cracking and a production method thereof

Abstract

The present invention discloses a hydrogen-induced cracking-resistant 09MnNiDR thick plate and a production method thereof. The chemical composition and weight percentage of the steel plate are as follows: C: 0.12-0.14%, Si: 0.20-0.30%, Mn: 0.90-1.0%, P ≤ 0.025%, S ≤ 0.003%, Ni: 0.75-0.80%, Alt: 0.020-0.035%, Ca ≤ 0.0030, Al / Ca: 10-15, S / Ca ≤ 1; the balance is Fe and unavoidable impurities. The production method includes clean steel smelting, ingot casting, ingot heating, steel plate rolling, and steel plate heat treatment. The 100-150 mm extra-thick 09MnNiDR steel plate provided by the present invention not only has good room temperature tensile strength and -70°C impact strength, but also has excellent hydrogen-induced cracking resistance.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a 09MnNiDR thick plate resistant to hydrogen-induced cracking and a production method thereof. Background Art

[0002] 09MnNiDR is a low-carbon, low-alloy steel plate with excellent overall performance, widely used in the manufacture of low-temperature equipment such as petroleum, coolers, compressor casings, and propane tanks. However, in recent years, changes in equipment structural design requirements have led to increasing steel plate thickness, even exceeding the standard upper limit of 120mm. Furthermore, technical requirements have become increasingly stringent. For example, the 09MnNiDR steel plate used in methanol scrubbers has been modified to include additional 1 / 2-point impact and HIC resistance.

[0003] The maximum 09MnNiDR steel plate thicknesses that can be produced by existing patents CN201910235150.3 and CN114318142A are 120mm and 130mm, respectively, and can meet certain low-temperature toughness requirements at the 1 / 2 point. However, their HIC resistance cannot be guaranteed, which poses a significant risk during use in hydrogen sulfide corrosive atmospheres. Secondly, to ensure high plasticity and toughness, 09MnNiDR steel plates generally use multi-element alloying. For example, CN201910235150.3 uses Nb+Ni+Ti, and CN114318142A uses Nb+Ni. This is not only costly but also prone to element segregation, forming inclusions that affect toughness and corrosion resistance at the 1 / 2 point.

[0004] The present invention adopts a low-carbon, low-alloy system design, uses steel ingots to achieve a large reduction process, innovates the clean steel smelting process, reduces the number of inclusions and controls their morphology, and combines reasonable rolling and heat treatment processes to obtain excellent comprehensive performance and HIC resistance, which is advanced and innovative. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a hydrogen-cracking-resistant 09MnNiDR thick plate and a production method thereof.

[0006] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0007] A hydrogen-induced cracking-resistant 09MnNiDR thick plate has the following chemical compositions and their mass percentages: C: 0.12-0.14%, Si: 0.20-0.30%, Mn: 0.90-1.0%, P≤0.025%, S≤0.003%, Ni: 0.75-0.80%, Alt: 0.020-0.035%, Ca≤0.0030, Al / Ca: 10-15, S / Ca≤1; the balance is Fe and unavoidable impurities.

[0008] The thickness specification of the steel plate is 100-150 mm.

[0009] The conventional mechanical properties of the steel plate meet the following requirements: room temperature tensile ReH: ≥300MPa, Rm: 450-570MPa, A ≥27.0%; -70°C transverse impact energy, ≥250J at 1 / 4, ≥200J at 1 / 2.

[0010] The steel plate structure is acicular ferrite + granular bainite structure, and the grain size is 9-10.

[0011] The steel plate has excellent resistance to hydrogen-induced cracking: no cracks are generated after being corroded for 96 hours in solution A.

[0012] The present invention also provides a production method of hydrogen-cracking-resistant 09MnNiDR thick plates, which includes clean steel smelting, steel ingot casting, steel ingot heating, steel plate rolling, and steel plate heat treatment.

[0013] The clean steel smelting process utilizes an electric furnace primary refining, LF refining, and VD degassing process. Primary refining involves peroxide tapping, with a carbon content of ≤0.04%. Carbon powder is first added to the LF ladle, stirred with a large amount of argon, and when the carbon content is adjusted to ≥0.06%, ferrosilicon and ferromanganese are then added sequentially for deoxidation, followed by aluminum wire for deep deoxidation. The LF white slag is held for 20-30 minutes. The VD ladle is fed with 60-70 m of Ca wire before vacuuming begins. The vacuum is maintained for 10-15 minutes before breaking. Ca wire is then fed again for 30-40 m. After vacuuming, soft blowing is performed for 10-15 minutes.

[0014] In the steel ingot casting process, the ladle is superheated at 32-37° C. when pouring, and the ingot mold thickness is 750-900 mm. After the steel ingot is demoulded, it is stacked and slowly cooled to room temperature.

[0015] The steel ingot heating process adopts a soaking furnace for heating, with a holding temperature of 1260-1280° C. and a holding time of 10-15 hours to ensure uniform burning through.

[0016] The steel plate rolling process has a compression ratio of ≥5, two-stage controlled rolling, an intermediate billet steel thickness of 180-230 mm, a second-stage rolling temperature of ≤860°C, watering after rolling, and a return to red temperature of 500-550°C.

[0017] The steel plate heat treatment process includes normalizing and tempering. Normalizing: Holding temperature 900-910°C for 100-120 minutes. After exiting the furnace, the steel plate is cooled in water at a roller speed of 2-3 m / min to 600-650°C, then immersed in a water tank to cool to room temperature. Tempering: Holding temperature 600-630°C for 150-200 minutes. After exiting the furnace, the steel plate is air-cooled.

[0018] The product standard of the hydrogen-induced cracking-resistant 09MnNiDR thick plate of the present invention refers to GB / T3531, and the product performance detection method refers to GB / T228.1, GB / T229, and GB / T8650.

[0019] The beneficial effects of adopting the above technical solution are:

[0020] (1) C and Mn elements have a strengthening effect, and a high-carbon, low-manganese design is adopted. Because C atoms are interstitial solid solutions and Mn is substitutional solid solutions, carbon segregation is easier to diffuse and eliminate than manganese segregation during the subsequent heating process, which reduces segregation, weakens the crack tendency, and improves HIC resistance. Secondly, low manganese reduces the formation tendency of MnS inclusions and also reduces the possibility of HIC generation.

[0021] (2) Single Ni element alloying: only a certain amount of Ni is added to improve the toughness of the matrix, eliminating the addition of microalloys such as Nb, V, and Ti, and avoiding the formation of such carbonitrides that deteriorate the toughness and corrosion resistance.

[0022] (3) The present invention has a wide range of P and S elements without excessive restrictions, and is more suitable for on-site large-scale production and promotion.

[0023] (4) In the LF process of the present invention, C is first used for deoxidation to form CO, which is diffused and removed; then Si is used for deoxidation to form large particle inclusions, which float up and are removed; finally, Al is used for deep deoxidation, which significantly reduces the content and level of inclusions.

[0024] (5) Due to deep deoxidation with Al, a certain amount of Al2O3 exists in the molten steel. These inclusions are sharp in shape and are not easily deformed during the subsequent rolling process, which can cause stress concentration and cracks. In addition, the MnS inclusions in the steel are mostly distributed in a banded manner, have strong anisotropy, and their expansion coefficient differs greatly from that of the steel matrix. The surrounding area is a sensitive area for microcracks, which also has a significant impact on the HIC resistance. The present invention adopts a staged Ca feeding treatment during the VD process to spheroidize the Al2O3 and MnS inclusions, surrounding them with a layer of calcium, forming spherical sulfides or composite oxides. Not only are these inclusions easier to float and remove, but the remaining spherical inclusions have low stress and a low tendency to crack.

[0025] (6) Experiments have shown that controlling a certain amount of S / Ca and Al / Ca ratios can achieve the best effect of spheroidizing inclusions. Therefore, the present invention adopts staged Ca feeding, and Ca feeding before vacuuming, which can fully spheroidize inclusions in the molten steel by utilizing the large argon stirring process in the VD furnace. However, Ca is very active and has low solubility, and the recovery rate of Ca before vacuuming is low. Therefore, it is necessary to feed a portion after vacuuming to improve the recovery rate and ensure the S / Ca and Al / Ca ratios.

[0026] (7) The present invention adopts the steel ingot forming process and uses a large reduction process to obtain a fine original structure. The normalizing process is to first cool to 600-650℃ in the acicular ferrite region at a certain cooling rate, and then quickly cool to room temperature to form granular bainite. The acicular ferrite formed first plays the role of dividing the original grains and refining the structure. The fine grain structure is an ideal structure for resisting HIC. Secondly, the high density of dislocations in the granular bainite and the finely dispersed carbonitrides can adsorb H atoms and make them evenly distributed in the structure, thereby reducing the regional H pressure and making it difficult to form HIC.

[0027] (8) The present invention strictly controls the smelting process, forms stable and feasible process parameters, regulates the microstructure of the steel plate, and ultimately obtains a steel plate with excellent comprehensive performance, which meets market demand. Implementation Method

[0028] The present invention will be further described in detail below with reference to specific embodiments.

[0029] The specifications and chemical compositions of the steel plates of Examples 1-6 are shown in Table 1, with the remainder being Fe and unavoidable impurities.

[0030] Table 1 Specifications and chemical composition of steel plates in Examples 1-6 (%)

[0031]

[0032] Example 1

[0033] The production method of the hydrogen-cracking resistant 09MnNiDR thick plate of this embodiment includes clean steel smelting, steel ingot casting, steel ingot heating, steel plate rolling, and steel plate heat treatment:

[0034] (1) Clean steel smelting process, using electric furnace primary refining + LF refining + VD degassing process. Primary refining peroxide tapping, C0.03%; LF sitting ladle first add carbon powder, stirring with large argon, adjust C to 0.066%, then add ferrosilicon and ferromanganese for deoxidation, and finally feed aluminum wire for deep deoxidation. LF white slag is kept for 22 minutes. VD sitting ladle feeds Ca wire for 64m, starts vacuuming, and vacuum is maintained for 10 minutes before breaking the air; Ca wire is fed again for 32m, and soft blowing is carried out for 13 minutes after vacuuming.

[0035] (2) Ingot casting process: the ladle is superheated at 33°C and the ingot mold thickness is 900 mm. After demoulding, the ingots are stacked and slowly cooled to room temperature.

[0036] (3) Ingot heating process: Use a soaking furnace for heating, with a holding temperature of 1265°C and a holding time of 10 hours to ensure uniform burning.

[0037] (4) Steel plate rolling process: compression ratio 8.6, two-stage controlled rolling, intermediate billet steel thickness 180mm, second-stage rolling temperature 848℃, watering after rolling, returning to red 500℃.

[0038] (5) Steel plate heat treatment process: including normalizing and tempering heat treatment. Normalizing: holding temperature 904℃, holding time 110min, cooling in water at a roller speed of 2.3m / min to 600℃, and then immersing in a water tank to cool to room temperature. Tempering: holding temperature 611℃, holding time 150min, and air cooling after leaving the furnace.

[0039] The performance test results of the 09MnNiDR thick plate resistant to hydrogen-induced cracking in this embodiment are shown in Table 2. The structure is acicular ferrite + granular bainite structure, and the grain size is 9.5.

[0040] Table 2 Mechanical properties of 09MnNiDR thick plate resistant to hydrogen induced cracking in Example 1

[0041]

[0042] Example 2

[0043] The production method of the hydrogen-cracking resistant 09MnNiDR thick plate of this embodiment includes clean steel smelting, steel ingot casting, steel ingot heating, steel plate rolling, and steel plate heat treatment:

[0044] (1) Clean steel smelting process, using electric furnace primary refining + LF refining + VD degassing process. Primary refining peroxide tapping, C0.04%; LF sitting ladle first add carbon powder, stirring with large argon, adjust C to 0.07%, then add ferrosilicon and ferromanganese for deoxidation, and finally feed aluminum wire for deep deoxidation. LF white slag is kept for 20 minutes. VD sitting ladle feeds Ca wire for 67m, starts vacuuming, and vacuum is maintained for 14 minutes before breaking the air; Ca wire is fed again for 40m, and soft blowing is carried out for 12 minutes after vacuuming.

[0045] (2) Ingot casting process: the ladle is superheated at 32°C and the ingot mold thickness is 800mm. After demoulding, the ingots are stacked and slowly cooled to room temperature.

[0046] (3) Ingot heating process: Use a soaking furnace for heating, with a holding temperature of 1260°C and a holding time of 11 hours to ensure uniform burning.

[0047] (4) Steel plate rolling process: compression ratio 8, two-stage controlled rolling, intermediate billet steel thickness 220mm, second-stage rolling temperature 860℃, watering after rolling, red return 520℃.

[0048] (5) Steel plate heat treatment process: including normalizing and tempering heat treatment. Normalizing: holding temperature 908℃, holding time 120min, cooling in water at a roller speed of 2m / min to 614℃, and then immersing in a water tank to cool to room temperature. Tempering: holding temperature 600℃, holding time 165min, and air cooling after leaving the furnace.

[0049] The performance test results of the hydrogen-induced cracking-resistant 09MnNiDR thick plate of this embodiment are shown in Table 3. The structure is acicular ferrite + granular bainite structure, and the grain size is 9.0.

[0050] Table 3 Mechanical properties of 09MnNiDR thick plate resistant to hydrogen induced cracking in Example 2

[0051]

[0052] Example 3

[0053] The production method of the hydrogen-cracking resistant 09MnNiDR thick plate of this embodiment includes clean steel smelting, steel ingot casting, steel ingot heating, steel plate rolling, and steel plate heat treatment:

[0054] (1) Clean steel smelting process, using electric furnace primary refining + LF refining + VD degassing process. Primary refining peroxide tapping, C0.025%; LF sitting ladle first add carbon powder, stirring with large argon, adjust C to 0.063%, then add ferrosilicon and ferromanganese for deoxidation, and finally feed aluminum wire for deep deoxidation. LF white slag is kept for 27 minutes. VD sitting ladle feeds Ca wire for 60m, starts vacuuming, and vacuum is maintained for 13 minutes before breaking the air; Ca wire is fed again for 30m, and soft blowing is carried out for 10 minutes after vacuuming.

[0055] (2) Ingot casting process: the ladle is superheated at 34°C and the ingot mold thickness is 840 mm. After demolding, the ingots are stacked and slowly cooled to room temperature.

[0056] (3) Ingot heating process: Use a soaking furnace for heating, with a holding temperature of 1280°C and a holding time of 12.5 hours to ensure uniform burning.

[0057] (4) Steel plate rolling process: compression ratio 6.2, two-stage controlled rolling, intermediate billet thickness 200mm, second-stage rolling temperature 837℃, watering after rolling, return to red 536℃.

[0058] (5) Steel plate heat treatment process: including normalizing and tempering heat treatment. Normalizing: holding temperature 910℃, holding time 100min, cooling in water at a roller speed of 2.5m / min to 633℃, and then immersing in water tank to cool to room temperature. Tempering: holding temperature 625℃, holding time 190min, and air cooling after leaving the furnace.

[0059] The performance test results of the hydrogen-induced cracking-resistant 09MnNiDR thick plate of this embodiment are shown in Table 4. The structure is acicular ferrite + granular bainite structure, and the grain size is 9.5.

[0060] Table 4 Mechanical properties of 09MnNiDR thick plate resistant to hydrogen induced cracking in Example 3

[0061]

[0062] Example 4

[0063] The production method of the hydrogen-cracking resistant 09MnNiDR thick plate of this embodiment includes clean steel smelting, steel ingot casting, steel ingot heating, steel plate rolling, and steel plate heat treatment:

[0064] (1) Clean steel smelting process, using electric furnace primary refining + LF refining + VD degassing process. Primary refining peroxide tapping, C0.037%; LF sitting ladle first add carbon powder, stirring with large argon, adjust C to 0.06%, then add ferrosilicon and ferromanganese for deoxidation, and finally feed aluminum wire for deep deoxidation. LF white slag is kept for 25 minutes. VD sitting ladle feeds Ca wire for 70m, starts vacuuming, and vacuum is maintained for 12 minutes before breaking the air; Ca wire is fed again for 35m, and soft blowing is carried out for 14 minutes after vacuuming.

[0065] (2) Ingot casting process: the ladle is superheated at 37°C and the ingot mold thickness is 780 mm. After demoulding, the ingots are stacked and slowly cooled to room temperature.

[0066] (3) Ingot heating process: Use a soaking furnace for heating, with a holding temperature of 1273°C and a holding time of 15 hours to ensure uniform burning.

[0067] (4) Steel plate rolling process: compression ratio 6.5, two-stage controlled rolling, intermediate billet thickness 230mm, second-stage rolling temperature 852℃, watering after rolling, red return 541℃.

[0068] (5) Steel plate heat treatment process: including normalizing and tempering heat treatment. Normalizing: holding temperature 900℃, holding time 115min, cooling in water at a roller speed of 2.7m / min to 620℃, and then immersing in water tank to cool to room temperature. Tempering: holding temperature 627℃, holding time 200min, and air cooling after leaving the furnace.

[0069] The performance test results of the hydrogen-induced cracking resistance 09MnNiDR thick plate of this embodiment are shown in Table 5. The structure is acicular ferrite + granular bainite structure, and the grain size is level 10.

[0070] Table 5 Mechanical properties of 09MnNiDR thick plate resistant to hydrogen induced cracking in Example 4

[0071]

[0072] Example 5

[0073] The production method of the hydrogen-cracking resistant 09MnNiDR thick plate of this embodiment includes clean steel smelting, steel ingot casting, steel ingot heating, steel plate rolling, and steel plate heat treatment:

[0074] (1) Clean steel smelting process, using electric furnace primary refining + LF refining + VD degassing process. Primary refining peroxide tapping, C0.033%; LF sitting ladle first add carbon powder, stirring with large argon, adjust C to 0.069%, then add ferrosilicon and ferromanganese for deoxidation, and finally feed aluminum wire for deep deoxidation. LF white slag is kept for 30 minutes. VD sitting ladle feeds Ca wire for 68m, starts vacuuming, and vacuum is maintained for 15 minutes before breaking the air; Ca wire is fed again for 38m, and soft blowing is carried out for 11 minutes after vacuuming.

[0075] (2) Ingot casting process: the ladle is superheated at 36°C and the ingot mold thickness is 810 mm. After demolding, the ingots are stacked and slowly cooled to room temperature.

[0076] (3) Ingot heating process: Use a soaking furnace for heating, with a holding temperature of 1277°C and a holding time of 14 hours to ensure uniform burning.

[0077] (4) Steel plate rolling process: compression ratio 5.7, two-stage controlled rolling, intermediate billet steel thickness 195mm, second-stage rolling temperature 843℃, watering after rolling, returning to red 550℃.

[0078] (5) Steel plate heat treatment process: including normalizing and tempering heat treatment. Normalizing: holding temperature 901℃, holding time 107min, cooling in water at a roller speed of 3m / min to 650℃, and then immersing in a water tank to cool to room temperature. Tempering: holding temperature 605℃, holding time 180min, and air cooling after leaving the furnace.

[0079] The performance test results of the hydrogen-induced cracking resistance 09MnNiDR thick plate of this embodiment are shown in Table 6. The structure is acicular ferrite + granular bainite structure, and the grain size is level 9.

[0080] Table 6 Mechanical properties of hydrogen-induced cracking-resistant 09MnNiDR thick plate of Example 5

[0081]

[0082] Example 6

[0083] The production method of the hydrogen-cracking resistant 09MnNiDR thick plate of this embodiment includes clean steel smelting, steel ingot casting, steel ingot heating, steel plate rolling, and steel plate heat treatment:

[0084] (1) Clean steel smelting process, using electric furnace primary refining + LF refining + VD degassing process. Primary refining peroxide tapping, C0.025%; LF sitting ladle first add carbon powder, stirring with large argon, adjust C to 0.072%, then add ferrosilicon and ferromanganese for deoxidation, and finally feed aluminum wire for deep deoxidation. LF white slag is kept for 29 minutes. VD sitting ladle feeds Ca wire for 62m, starts vacuuming, and vacuum is maintained for 11 minutes before breaking the air; Ca wire is fed again for 36m, and soft blowing is carried out for 15 minutes after vacuuming.

[0085] (2) Ingot casting process: the ladle is superheated at 35°C and the ingot mold thickness is 750mm. After demolding, the ingots are stacked and slowly cooled to room temperature.

[0086] (3) Ingot heating process: Use a soaking furnace for heating, with a holding temperature of 1264°C and a holding time of 13.2 hours to ensure uniform burning.

[0087] (4) Steel plate rolling process: compression ratio 5, two-stage controlled rolling, intermediate billet thickness 210mm, second-stage rolling temperature 835℃, watering after rolling, red return 518℃.

[0088] (5) Steel plate heat treatment process: including normalizing and tempering heat treatment. Normalizing: holding temperature 907℃, holding time 103min, cooling in water at a roller speed of 2.8m / min to 645℃, and then immersing in water tank to cool to room temperature. Tempering: holding temperature 630℃, holding time 170min, and air cooling after leaving the furnace.

[0089] The performance test results of the hydrogen-induced cracking resistance 09MnNiDR thick plate of this embodiment are shown in Table 7. The structure is acicular ferrite + granular bainite structure, and the grain size is level 10.

[0090] Table 7 Mechanical properties of 09MnNiDR thick plate resistant to hydrogen induced cracking in Example 6

[0091]

[0092] The above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that the present invention can still be modified or replaced by equivalents. Any modification or partial replacement that does not depart from the spirit and scope of the present invention should be included in the scope of the claims of the present invention.

Claims

1. A 09MnNiDR thick plate resistant to hydrogen-induced cracking, characterized in that: The chemical composition of the steel plate and its mass percentage are: C: 0.12-0.14%, Si: 0.20-0.30%, Mn: 0.90-1.0%, P≤0.025%, S≤0.003%, Ni: 0.75-0.80%, Alt: 0.020-0.035%, Ca≤0.0030, Al / Ca: 10-15, S / Ca≤1; the balance is Fe and unavoidable impurities; The conventional mechanical properties of the steel plate meet the following requirements: room temperature tensile ReH: ≥300MPa, Rm: 450-570MPa, A ≥27.0%; -70°C transverse impact energy, 1 / 4 ≥250J, 1 / 2 ≥200J; The steel plate has a microstructure of acicular ferrite + granular bainite, with a grain size of 9-10. The steel plate has excellent resistance to hydrogen-induced cracking: no cracks are generated after corrosion in solution A for 96 hours. The production method of the steel plate includes clean steel smelting, steel ingot casting, steel ingot heating, steel plate rolling, and steel plate heat treatment. The steel plate heat treatment process includes normalizing and tempering heat treatment. The normalizing process is as follows: the holding temperature is 900-910°C for 100-120 minutes, and the steel plate is cooled in water at a roller speed of 2-3 m / min to 600-650°C after being taken out of the furnace, and then immersed in a water tank to cool to room temperature. The tempering process is as follows: the holding temperature is 600-630°C for 150-200 minutes, and the steel plate is air-cooled after being taken out of the furnace. In the clean steel smelting process, the VD sitting bag feeds the Ca wire for 60-70m, starts vacuuming, and the vacuum is maintained for 10-15 minutes before breaking the air; the Ca wire is fed again for 30-40m, and soft blowing is carried out for 10-15 minutes after vacuuming.

2. The hydrogen-induced cracking resistant 09MnNiDR thick plate according to claim 1, characterized in that: The thickness specification of the steel plate is 100-150 mm.

3. A method for producing the hydrogen-cracking-resistant 09MnNiDR thick plate according to claim 1 or 2, characterized in that , including clean steel smelting, ingot casting, ingot heating, steel plate rolling, and steel plate heat treatment; the steel plate heat treatment process includes normalizing + tempering heat treatment; the normalizing: holding temperature 900-910℃, holding time 100-120min, after leaving the furnace, put into water to cool to 600-650℃ at a roller speed of 2-3m / min, and then immerse in a water tank to cool to room temperature; the tempering: holding temperature 600-630℃, holding time 150-200min, and air cooling after leaving the furnace; In the clean steel smelting process, the VD sitting bag feeds the Ca wire for 60-70m, starts vacuuming, and the vacuum is maintained for 10-15 minutes before breaking the air; the Ca wire is fed again for 30-40m, and soft blowing is carried out for 10-15 minutes after vacuuming.

4. The method for producing a hydrogen-cracking-resistant 09MnNiDR thick plate according to claim 3, characterized in that: The clean steel smelting process adopts electric furnace primary smelting + LF refining + VD degassing process; primary smelting is peroxidized steel, C≤0.04%; carbon powder is first added to the LF sitting ladle, and large argon is stirred. After the C is adjusted to ≥0.06%, ferrosilicon and ferromanganese are added in sequence for deoxidation, and finally aluminum wire is fed for deep deoxidation; the LF white slag is maintained for 20-30 minutes.

5. The method for producing a hydrogen-cracking-resistant 09MnNiDR thick plate according to claim 3, characterized in that: In the steel ingot casting process, the ladle is superheated at 32-37° C. when pouring, and the ingot mold thickness is 750-900 mm. After the steel ingot is demoulded, it is stacked and slowly cooled to room temperature.

6. The method for producing a hydrogen-cracking-resistant 09MnNiDR thick plate according to claim 3, characterized in that: The steel ingot heating process adopts a soaking furnace for heating, with a holding temperature of 1260-1280° C. and a holding time of 10-15 hours to ensure uniform burning through.

7. The method for producing a hydrogen-cracking-resistant 09MnNiDR thick plate according to claim 3, characterized in that: The steel plate rolling process has a compression ratio of ≥5, two-stage controlled rolling, an intermediate billet steel thickness of 180-230 mm, a second-stage rolling temperature of ≤860°C, watering after rolling, and a return to red temperature of 500-550°C.

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