A method of producing electrosteel

Abstract

The application relates to a production method of electroslag steel and belongs to the technical field of alloy structural steel production. In order to improve the finished product qualified rate of the electroslag steel, the process flow of the production method is as follows: converter smelting+LF+VD->round billet continuous casting->slow cooling->shot blasting->electroslag remelting->shell cooling->large bar rolling->slow cooling->annealing->straightening->grinding->flaw detection->inspection->delivery; the material composition of the electroslag steel is as follows: carbon content 0.30-0.32wt%, silicon content 1.08-1.15wt%, manganese content 0.95-1.25wt%, chromium content 0.95-1.05wt%, aluminum content 0.035-0.050wt%, titanium content 0.015-0.025wt%, phosphorus content <=0.015wt%, sulfur content <=0.010wt%, and the balance is iron. The electroslag steel prepared by the application has qualified performance, and the loss of the steel caused by the quality is avoided.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of alloy structural steel production, and particularly relates to a production method of electroslag steel. BACKGROUND

[0002] The electroslag is a secondary refining technology, which is a comprehensive metallurgical casting process combining secondary refining of molten steel and directional solidification. The principle is that the electric current passes through the liquid slag pool to resist heat, melts the metal electrode, collects the molten metal into droplets, and then the droplets fall through the slag layer into the metal pool, and then crystallize and solidify into ingots in the water-cooled crystallizer. Due to the unqualified burning loss of Si and Mn elements in the electroslag process, the performance of the rolled material is unqualified, and the decrease of the solidification effect caused by the increase of the diameter of the electroslag ingot affects the central shrinkage hole and porosity level in the ingot, thereby affecting the quality of the casting and the stability. SUMMARY

[0003] The application aims to improve the qualified rate of the electroslag steel, and provides a production method of electroslag steel.

[0004] To achieve the above-mentioned purpose, the application realizes the following technical scheme:

[0005] The production method of the electroslag steel has a process flow of converter smelting+LF+VD→round billet continuous casting→slow cooling→shot blasting→electroslag remelting→shell cooling→large bar rolling→slow cooling→annealing→straightening→grinding→flaw detection→inspection→delivery.

[0006] The material composition of the electroslag steel comprises 0.30-0.32wt% of carbon, 1.08-1.15wt% of silicon, 0.95-1.25wt% of manganese, 0.95-1.05wt% of chromium, 0.035-0.050wt% of aluminum, 0.015-0.025wt% of titanium, ≤0.015wt% of phosphorus, ≤0.010wt% of sulfur, and the balance of iron.

[0007] Further, the slag material ratio and dosage when tapping in the converter smelting step are as follows: 600Kg of white ash, 300Kg of deoxidizing and desulfurizing refining slag, 100kg of Al ingot is added when tapping, the C is controlled to be 0.08-0.10wt% when tapping, the P is ≤0.012wt% when tapping, and the tapping temperature is 1610-1640℃.

[0008] Further, the LF refining step adds lime 200-300 kg, mixed deoxidizer 70 kg, white slag retention time 15-20 min; the VD vacuum step has a vacuum degree of ≤67 Pa, vacuum retention time 15-30 min, fixed hydrogen after breaking vacuum ≤1.2 ppm, soft blowing time 15-20 min, and package insulation agent and carbonized rice husk are added after breaking vacuum, with the slag surface slightly moving and the steel liquid not exposed.

[0009] Further, the round billet continuous casting step has a liquidus temperature of 1491 ℃, a continuous casting superheat controlled at 20-30 ℃, a casting speed controlled at 0.31 m / min, a crystallizer protective slag JLBM-YD01 protective slag, a crystallizer water flow 4500 L / min, a continuous electromagnetic stirring current 200 A and a frequency 3 Hz, a terminal electromagnetic stirring forward stirring for 25 s, then stopping for 5 s, then reverse stirring for 25 s, then stopping for 5 s, a stirring current 400 A and a frequency 8 Hz.

[0010] Further, the slow cooling step after the round billet continuous casting has an entry pit temperature of 500-520 ℃, a holding time 60-70 h, and an opening pit temperature ≤200 ℃.

[0011] Further, the shot blasting frequency is 2 times, and the billet surface is checked after shot blasting to ensure that the billet surface is good, without oil, surface scarring, iron scale, and surface rust.

[0012] Further, the electroslag remelting step uses four-component slag smelting, including CaF2, Al2O3, CaO, and MgO, with the amounts being 60 kg, 90 kg, 40 kg, and 10 kg, respectively, the slag is added uniformly within the slag adding time, the slag material heating temperature is ensured to be ≥800 ℃, the holding time is 6-7 h, the slag adding time is set to 35 min, the refining time is 35 min, the current raising time is ≤30 min, the process current raising time is ≤30 min, the mold cooling time is 90 min, the cover cooling time is 96 h, and argon protection is done during the electroslag remelting process. The argon flow is 0.6-1.0 m 3 / h, the chemical composition of the electroslag ingot is controlled to be lower than that of the electrode billet by 0.04-0.17 wt% for Si, 0.07-0.15 wt% for Mn, and 0.08-0.01 wt% for Ti.

[0013] Further, the large rod rolling adopts a cold charging mode, the preheating segment temperature is 800-860 ℃, the heating 1 segment temperature is 950-1150 ℃, the heating 2 segment temperature is 1220-1280 ℃, the soaking segment temperature is 1230-1270 ℃, the total heating time is 8-10 h, the high-temperature diffusion time is 3.5-4 h, the rolling size is rolled according to a positive deviation, and the cutting mode is saw cutting.

[0014] Further, the slow cooling pit temperature of the large bar after rolling is 500-550 DEG C, and the slow cooling time is 48 hours.

[0015] According to the production method of the large-specification bearing steel of claim 9, the annealing step is slow cooling at 690-710 DEG C for 0.7-0.9Q, Q is the charging amount, and furnace cooling for 3 hours.

[0016] The beneficial effects of the present application are:

[0017] The production method of the electric steel of the present application can prepare electric steel materials with qualified performance and eliminate the loss of steel materials caused by quality problems. DETAILED DESCRIPTION DETAILED DESCRIPTION

[0019] The production method of the electric steel comprises the following steps: converter smelting + LF + VD → round billet continuous casting → slow cooling → shot blasting → electric remelting → cover cooling → large bar rolling → slow cooling → annealing → straightening → grinding → flaw detection → inspection → delivery.

[0020] The material composition of the electric steel comprises the following components: carbon content 0.30-0.32 wt%, silicon content 1.08-1.15 wt%, manganese content 0.95-1.25 wt%, chromium content 0.95-1.05 wt%, aluminum content 0.035-0.050 wt%, titanium content 0.015-0.025 wt%, phosphorus content ≤0.015 wt%, sulfur content ≤0.010 wt%, and the balance is iron.

[0021] Further, in the converter smelting step, the slag material ratio and dosage at tapping are as follows: white ash 600 Kg, deoxidizing and desulfurizing refining slag 300 Kg, and Al ingot 100 Kg is added at tapping, the C content is controlled to be 0.08-0.10 wt% at tapping, the P content is ≤0.012 wt% at tapping, and the tapping temperature is 1610-1640 DEG C.

[0022] Further, in the LF refining step, 200-300 kg of lime and 70 kg of mixed deoxidizing agent are added at one-time power feeding, the white slag retention time is 15-20 min; in the VD vacuum step, the vacuum degree is ≤67 Pa, the vacuum retention time is 15-30 min, the hydrogen content after breaking the vacuum is ≤1.2 ppm, the soft blowing time is 15-20 min, and the package insulation agent and carbonized rice husk are added after breaking the vacuum, so that the slag surface is slightly moving and the molten steel is not exposed.

[0023] Further, the liquidus temperature in the round billet continuous casting step is 1491 °C, the continuous casting superheat is controlled at 20-30 °C, the withdrawal speed is controlled at 0.31 m / min, the mold powder is JLBM-YD01 mold powder, the mold water flow is 4500 L / min, the electromagnetic stirring continuous stirring current is 200 A, the frequency is 3 Hz, the end electromagnetic stirring is forward stirring for 25 s, then stopping for 5 s, then reverse stirring for 25 s, then stopping for 5 s, the stirring current is 400 A, and the frequency is 8 Hz.

[0024] The round billet continuous casting process is shown in Table 1:

[0025] Table 1 round billet continuous casting technical parameters

[0026]

[0027] Further, the slow cooling step after the round billet continuous casting has an in-pit temperature of 500-520 °C, a holding time of 60-70 h, and an opening cover temperature of ≤200 °C.

[0028] Further, the shot blasting frequency is 2 times, and the billet surface is checked after shot blasting to ensure that the billet surface is good, without oil, surface scarring, iron scale, and surface rust.

[0029] Further, the electroslag remelting step uses four-element slag smelting, including CaF2, Al2O3, CaO, and MgO, with a dosage of 60 kg, 90 kg, 40 kg, and 10 kg, respectively, the slag is added uniformly within the slag adding time, the slag material heating temperature is ensured to be ≥800 °C, the holding time is 6-7 h, the slag adding time is set to 35 min, the refining time is 35 min, the current lifting time is ≤30 min, the process current lifting time is ≤30 min, the mold cooling time is 90 min, the cover cooling time is 96 h, and argon protection is done during the electroslag remelting process. The argon flow is 0.6-1.0 m 3 / h, the electroslag ingot chemical composition Si is controlled to be 0.04-0.17 wt% lower than the electrode billet smelting composition, Mn is controlled to be 0.07-0.15 wt% lower, and Ti is controlled to be 0.08-0.01 wt% lower.

[0030] The electroslag remelting process is shown in Table 2:

[0031] Table 2 electroslag remelting technical parameters

[0032]

[0033] Further, the large bar rolling adopts cold charging mode, the preheating section temperature is 800-860℃, the heating 1 section temperature is 950-1150℃, the heating 2 section temperature is 1220-1280℃, the soaking section temperature is 1230-1270℃, the total heating time is 8-10h, the high temperature diffusion time is 3.5-4h, the rolling size is rolled according to the positive deviation, and the cutting mode is saw cutting.

[0034] Further, the slow cooling after the large bar rolling is at a pit temperature of 500-550℃, and the slow cooling time is 48 hours.

[0035] The production method of the large-specification bearing steel according to claim 9, characterized in that the annealing step is slow cooling at 690-710℃ for 0.7-0.9Q, Q is the charging amount, and furnace cooling for 3h. Specific embodiment two:

[0037] A production method of an electroslag steel, wherein the process flow of the production method of the electroslag steel is converter smelting+LF+VD→round billet continuous casting→slow cooling→shot blasting→electroslag remelting→shell cooling→large bar rolling→slow cooling→annealing→straightening→grinding→flaw detection→inspection→delivery;

[0038] The material composition of the electroslag steel is: carbon content 0.30wt%, silicon content 1.08wt%, manganese content 0.95wt%, chromium content 0.95wt%, aluminum content 0.035wt%, titanium content 0.015wt%, phosphorus content ≤0.015wt%, sulfur content ≤0.010wt%, and the balance is iron.

[0039] Further, in the converter smelting step, the slag material ratio and amount at tapping are: white ash 600Kg, deoxidizing and desulfurizing refining slag 300Kg, Al ingot 100kg is added at tapping, the C content is controlled to be 0.08wt% at tapping, the P content is ≤0.012wt% at tapping, and the tapping temperature is 1610℃.

[0040] Further, in the LF refining step, 200kg of lime and 70kg of mixed deoxidizing agent are added at one-time power transmission, the white slag retention time is 15min; in the VD vacuum step, the vacuum degree is ≤67Pa, the vacuum retention time is 15min, the hydrogen content after breaking the vacuum is ≤1.2ppm, the soft blowing time is 15min, and the package insulating agent and carbonized rice husk are added after breaking the vacuum, so as to achieve the condition of slight movement of the slag surface and non-exposure of the molten steel.

[0041] Further, the liquidus temperature in the round billet continuous casting step is 1491℃, the overheat degree of continuous casting is controlled at 20℃, the pulling speed is controlled at 0.31m / min, the mold powder is JLBM-YD01 mold powder, the water flow of the mold is 4500L / min, the electromagnetic stirring current is 200A and the frequency is 3Hz, the end electromagnetic stirring is forward stirring for 25s, then stopping for 5s, then reverse stirring for 25s, then stopping for 5s, the stirring current is 400A and the frequency is 8Hz.

[0042] Further, the pit temperature after the slow cooling step of the round billet continuous casting is 500℃, the holding time is 60h, the opening cover temperature is ≤200℃.

[0043] Further, the shot blasting frequency is 2 times, the billet surface is checked after shot blasting, and the billet surface is ensured to be good, without oil, surface scarring, iron scale and surface rust.

[0044] Further, the electroslag remelting step adopts four-element slag smelting, including CaF2, Al2O3, CaO and MgO, and the amounts are 60kg, 90kg, 40kg and 10kg respectively, the slag is added uniformly within the slag adding time, the slag heating temperature is ensured to be ≥800℃, the holding time is 6h, the slag adding time is set to 35min, the refining time is 35min, the current lifting time is ≤30min, the process current lifting time is ≤30min, the mold cooling time is 90min, the cover cooling time is 96h, and the argon protection is well done in the electroslag remelting process. The argon flow is 0.6m 3 / h, the chemical composition of the electroslag ingot is controlled to be lower than that of the electrode billet by 0.04wt% of Si, 0.07wt% of Mn and 0.08wt% of Ti.

[0045] Further, the large rod rolling adopts cold charging, the preheating segment temperature is 800℃, the heating 1 segment temperature is 950℃, the heating 2 segment temperature is 1220℃, the soaking segment temperature is 1230℃, the total heating time is 8h, the high-temperature diffusion time is 3.5h, the rolling size is rolled according to the positive deviation, and the cutting mode is saw cutting.

[0046] Further, the slow cooling pit temperature after the large rod rolling is 500℃, and the slow cooling time is 48h.

[0047] The production method of the large-specification bearing steel according to claim 9, characterized in that the annealing step is slow cooling at 690℃ for 0.7Q, Q being the charging amount, and furnace cooling for 3h.

[0048] The chemical composition test results of the electroslag steel produced by the production method of the electroslag steel according to the embodiment are shown in Table 3.

[0049] Table 3 Chemical composition test results of the electroslag steel

[0050] Position C Si Mn P S Cr Ni Mo V Ti Cu Al Head 0.29 1.02 0.93 0.011 0.002 0.96 0.03 0.01 0.01 0.01 0.04 0.022 Tail 0.28 1.03 0.92 0.014 0.003 0.97 0.03 0.01 0.01 0.01 0.05 0.031 Head 0.29 1.02 0.92 0.009 0.003 0.98 0.03 0.01 0.01 0.01 0.05 0.030 Tail 0.29 1.00 0.85 0.015 0.002 0.91 0.03 0.01 0.01 0.01 0.05 0.041 Head 0.29 1.01 0.92 0.010 0.003 0.85 0.03 0.03 0.02 0.011 0.04 0.034 Tail 0.30 1.01 0.86 0.014 0.002 0.94 0.03 0.02 0.01 0.007 0.04 0.044 Head 0.29 1.02 0.85 0.015 0.002 0.93 0.03 0.01 0.01 0.007 0.04 0.034 Tail 0.30 1.03 0.92 0.010 0.002 0.95 0.03 0.01 0.01 0.009 0.04 0.052 Head 0.29 0.92 0.92 0.006 0.003 0.96 0.03 0.01 0.01 0.009 0.04 0.016 Tail 0.29 1.05 0.90 0.010 0.002 0.93 0.03 0.01 0.01 0.008 0.04 0.035 Head 0.29 0.96 0.88 0.013 0.003 0.92 0.02 0.01 0.01 0.008 0.04 0.024 Tail 0.28 0.99 0.86 0.016 0.002 0.95 0.02 0.01 0.01 0.007 0.04 0.039 Head 0.29 0.97 0.93 0.008 0.003 0.96 0.02 0.01 0.01 0.010 0.04 0.022 Tail 0.30 0.97 0.90 0.012 0.002 0.97 0.03 0.01 0.01 0.007 0.04 0.038

[0051] According to the chemical composition inspection result of the electroslag steel, Si is lower than the electrode blank smelting composition by 0.04-0.17, Mn is lower by 0.07-0.15, Ti is lower by about 0.01, and Al composition changes little.

[0052] The mechanical property inspection result is shown in Table 4:

[0053] Table 4 Mechanical property inspection result

[0054] Specific embodiment three:

[0056] A production method of an electroslag steel, the process flow of the production method of the electroslag steel is converter smelting + LF + VD → round billet continuous casting → slow cooling → shot blasting → electroslag remelting → cover cooling → large bar rolling → slow cooling → annealing → straightening → grinding → flaw detection → inspection and examination → hand over;

[0057] The material composition of the electroslag steel is: carbon content 0.32wt%, silicon content 1.15wt%, manganese content 1.25wt%, chromium content 1.05wt%, aluminum content 0.050wt%, titanium content 0.025wt%, phosphorus content ≤0.015wt%, sulfur content ≤0.010wt%, and the balance is iron.

[0058] Further, the slag material ratio and dosage at tapping in the converter smelting step are: white ash 600Kg, deoxidizing and desulfurizing refining slag 300Kg, Al ingot 100kg is added at tapping, C is controlled to be 0.10wt% at tapping, P ≤0.012wt% at tapping, and the tapping temperature is 1640℃.

[0059] Further, in the LF refining step, 300kg of lime and 70kg of mixed deoxidizing agent are added at one-time power transmission, the white slag retention time is 20min; in the VD vacuum step, the vacuum degree is ≤67Pa, the vacuum retention time is 30min, the hydrogen content after breaking vacuum is ≤1.2ppm, the soft blowing time is 20min, and the package insulating agent and carbonized rice husk are added after breaking vacuum, with the slag surface slightly moving and the molten steel not being exposed.

[0060] Further, in the round billet continuous casting step, the liquidus temperature is 1491℃, the continuous casting superheat is controlled at 30℃, the withdrawal speed is controlled at 0.31m / min, the crystallizer protection slag adopts JLBM-YD01 protection slag, the crystallizer water flow is 4500L / min, the electromagnetic stirring continuous stirring current is 200A and the frequency is 3Hz, the end electromagnetic stirring is forward stirring for 25s, then stopping for 5s, then reverse stirring for 25s, then stopping for 5s, the stirring current is 400A and the frequency is 8Hz.

[0061] Further, the slow cooling step after the round billet continuous casting has a pit temperature of 520℃, a holding time of 70h, and an uncovering temperature of ≤200℃.

[0062] Further, the shot blasting frequency is 2 times, and the billet surface is checked after shot blasting to ensure that the billet surface is good, free of oil, surface scarring, iron oxide scale, and surface rust.

[0063] Further, the electroslag remelting step adopts four-element slag smelting, including CaF2, Al2O3, CaO, and MgO, and the amounts are 60kg, 90kg, 40kg, and 10kg, respectively. The slag is added uniformly within the slag adding time, the slag material heating temperature is ensured to be ≥800℃, the holding time is 6-7h, the slag adding time is set to 35min, the refining time is 35min, the current raising time is ≤30min, the process current raising time is ≤30min, the mold cooling time is 90min, the cover cooling time is 96h, and argon protection is done during the electroslag remelting process. The argon flow is 1.0m 3 / h, the chemical composition of the electroslag ingot is controlled to be lower than the composition of the electrode billet by 0.17wt% for Si, 0.15wt% for Mn, and 0.01wt% for Ti.

[0064] Further, the large rod rolling adopts cold charging, the preheating segment temperature is 860℃, the heating 1 segment temperature is 1150℃, the heating 2 segment temperature is 1280℃, the soaking segment temperature is 1270℃, the total heating time is 10h, the high-temperature diffusion time is 4h, the rolling size is rolled according to a positive deviation, and the cutting method is sawing.

[0065] Further, the slow cooling after the large rod rolling has a pit temperature of 550℃ and a slow cooling time of 48h.

[0066] The production method of a large-specification bearing steel according to claim 9, characterized in that the annealing step is slow cooling followed by 710℃ holding for 0.9Q, Q being the charging amount, and furnace cooling for 3h.

[0067] The production method of a large-specification bearing steel according to the embodiment has the mechanical properties of the produced electroslag steel as shown in Table 5.

[0068] Table 5: Mechanical property test results

[0069] Specific implementation method four

[0071] A production method of an electroslag steel, the process flow of the production method of the electroslag steel being converter smelting+LF+VD→round billet continuous casting→slow cooling→shot blasting→electroslag remelting→cover cooling→large rod rolling→slow cooling→annealing→straightening→grinding→flaw detection→inspection and checking→handover;

[0072] The material composition of the electroslag steel is: carbon content 0.31wt%, silicon content 1.11wt%, manganese content 1.10wt%, chromium content 1.02wt%, aluminum content 0.040wt%, titanium content 0.020wt%, phosphorus content ≤0.015wt%, sulfur content ≤0.010wt%, and the balance is iron.

[0073] Further, the slag ratio and dosage during tapping in the converter smelting step are: white ash 600Kg, deoxidizing and desulfurizing refining slag 300Kg, and Al ingot 100kg is added during tapping, the C is controlled to be 0.09wt% during tapping, the P is ≤0.012wt% during tapping, and the tapping temperature is 1620℃.

[0074] Further, in the LF refining step, 240kg of lime and 70kg of mixed deoxidizing agent are added during the first power transmission, the white slag retention time is 15min; in the VD vacuum step, the vacuum degree is ≤67Pa, the vacuum retention time is 20min, the hydrogen content after breaking the vacuum is ≤1.2ppm, the soft blowing time is 15min, and the package insulation agent and carbonized rice husk are added after breaking the vacuum, and the slag surface is slightly moving and the molten steel is not exposed.

[0075] Further, in the round billet continuous casting step, the liquidus temperature is 1491℃, the overheat degree of continuous casting is controlled to be 20-30℃, the withdrawal speed is controlled to be 0.31m / min, the crystallizer protection slag adopts JLBM-YD01 protection slag, the crystallizer water flow is 4500L / min, the electromagnetic stirring continuous stirring current is 200A, the frequency is 3Hz, the end electromagnetic stirring is forward stirring for 25s, then stopping for 5s, then reverse stirring for 25s, then stopping for 5s, the stirring current is 400A, and the frequency is 8Hz.

[0076] Further, in the slow cooling step after the round billet continuous casting, the pit temperature is 510℃, the holding time is 65h, the cover is opened, and the pit temperature is ≤200℃.

[0077] Further, the shot blasting frequency is 2 times, the billet surface is checked after shot blasting, and the billet surface is ensured to be good, without oil, surface scarring, iron scale, and surface rust.

[0078] Further, in the electroslag remelting step, four-component slag smelting is adopted, including CaF2, Al2O3, CaO, and MgO, and the dosages are 60kg, 90kg, 40kg, and 10kg respectively, the slag is added uniformly within the slag adding time, the slag heating temperature is ensured to be ≥800℃, the holding time is 6.5h, the slag adding time is set to be 35min, the refining time is 35min, the current lifting time is ≤30min, the process current lifting time is ≤30min, the mold cooling time is 90min, the cover cooling time is 96h, and the argon protection is well done during the electroslag remelting process. The argon flow is 1.0m 3h, the control electroslag ingot chemical composition Si is 0.06wt% lower than the electrode blank smelting composition, Mn is 0.08wt% lower, and Ti is 0.09wt% lower.

[0079] Further, the large bar rolling adopts a cold charging mode, the preheating section temperature is 820 DEG C, the heating 1 section temperature is 1050 DEG C, the heating 2 section temperature is 1240 DEG C, the soaking section temperature is 1270 DEG C, the total heating time is 9h, the high temperature diffusion time is 4h, the rolling size is rolled according to a positive deviation, and the cutting mode is saw cutting.

[0080] Further, the slow cooling after the large bar rolling is at a pit temperature of 520 DEG C, and the slow cooling time is 48h.

[0081] The production method of the large-specification bearing steel according to claim 9, characterized in that the annealing step is slow cooling at 690 DEG C for 0.8Q, Q being the charging amount, and furnace cooling for 3h.

[0082] It is to be noted that the terms "first", "second", and so on, and the like relational terms only serve to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Also, the terms "comprising", "containing" or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article or apparatus that comprises a list of elements does not only include those elements, but also other elements not explicitly listed, or other elements inherent to such process, method, article or apparatus. Without more limitations, an element defined by the phrase "comprising a……" does not exclude the presence of additional identical elements in the process, method, article or apparatus that includes the element.

[0083] Although the present application has been described above with reference to specific embodiments, various modifications can be made to it without departing from the scope of the application, and equivalent components can be substituted for those components. In particular, each feature disclosed in the specific embodiments of the present application can be used in any combination with each other feature disclosed in the present application, unless there is a structural conflict. The combinations of these features are not exhaustively described in the present specification, which is merely for the purpose of omitting the length and saving resources. Therefore, the present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for producing electroslag steel, characterized in that, The process flow of the electroslag steel production method is as follows: converter smelting + LF + VD → round billet continuous casting → slow cooling → shot blasting → electroslag remelting → hood cooling → bar rolling → slow cooling → annealing → straightening → grinding → flaw detection → inspection → delivery. The material composition of the electroslag steel is as follows: carbon content 0.30~0.32wt%, silicon content 1.08~1.15wt%, manganese content 0.95~1.25wt%, chromium content 0.95~1.05wt%, aluminum content 0.035~0.050wt%, and titanium content 0.015~0.025wt%. Phosphorus content ≤ 0.015 wt%, sulfur content ≤ 0.010 wt%, balance is iron; In the LF refining step, 200-300 kg of lime and 70 kg of mixed deoxidizer are added during the first power supply, and the white slag is maintained for 15-20 minutes. In the VD vacuum step, the vacuum degree is ≤67 Pa, the vacuum maintenance time is 15-30 minutes, the hydrogen concentration after breaking the vacuum is ≤1.2 ppm, the soft blowing time is 15-20 minutes, and the heat preservation agent and carbonized rice husks are added after breaking the vacuum, so that the slag surface moves slightly and the molten steel is not exposed. In the continuous casting step of the round billet, the liquidus temperature is 1491℃, the superheat of continuous casting is controlled at 20-30℃, the casting speed is controlled at 0.31m / min, the mold flux is JLBM-YD01, the flow rate of the mold water is 4500L / min, the electromagnetic stirring is continuously stirred with a current of 200A and a frequency of 3Hz, the end electromagnetic stirring is forward stirring for 25s then stopped for 5s, then reverse stirring for 25s then stopped for 5s, the stirring current is 400A and the frequency is 8Hz; The electroslag remelting step employs quaternary slag smelting, comprising CaF2, Al2O3, CaO, and MgO, with amounts of 60 kg, 90 kg, 40 kg, and 10 kg respectively. Slag is added evenly within the specified time, ensuring the slag heating temperature is ≥800℃, with a holding time of 6–7 hours. The slag addition time is set to 35 minutes, the refining time to 35 minutes, the current increase time to ≤30 minutes, the process current increase time to ≤30 minutes, the mold cooling time to 90 minutes, and the cover cooling time to 96 hours. Argon gas protection is maintained throughout the electroslag remelting process, with an argon gas flow rate of 0.6–1.0 m³ / h. 3 / h, the chemical composition of the electroslag ingot is controlled to be 0.04-0.17 wt% lower for Si, 0.07-0.15 wt% lower for Mn, and 0.08-0.01 wt% lower for Ti than that of the electrode billet smelting composition; The bar rolling adopts a cold charging method. The preheating section temperature is 800-860℃, the heating section 1 temperature is 950-1150℃, the heating section 2 temperature is 1220-1280℃, the soaking section temperature is 1230-1270℃, the total heating time is 8-10h, the high temperature diffusion time is 3.5-4h, the rolling size is rolled according to positive deviation, and the cutting method is sawing.

2. The method for producing electroslag steel according to claim 1, characterized in that, The slag proportions and amounts during tapping in the converter smelting process are as follows: 600 kg of quicklime, 300 kg of deoxidizing and desulfurizing refining slag, 100 kg of Al ingots added during tapping, C controlled at 0.08~0.10 wt% during tapping, P ≤ 0.012 wt% during tapping, and tapping temperature of 1610~1640℃.

3. The method for producing electroslag steel according to claim 2, characterized in that, The slow cooling step after continuous casting of the round billet involves a pit temperature of 500-520℃, a holding time of 60-70 hours, and a pit opening temperature of ≤200℃.

4. The method for producing electroslag steel according to claim 3, characterized in that, The shot blasting is performed twice. After shot blasting, the surface of the billet is inspected to ensure that the surface of the billet is in good condition, free of oil, surface scars, iron oxide scale, and surface rust.

5. The method for producing electroslag steel according to claim 4, characterized in that, The temperature of the rolled bar in the slow cooling pit is 500-550℃, and the slow cooling time is 48 hours.

6. The method for producing electroslag steel according to claim 5, characterized in that, The annealing step involves slow cooling followed by holding at 690–710℃ for 0.7–0.9Q, where Q is the furnace charge, and then furnace cooling for 3 hours.

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