A method for smelting low-silicon aluminum steel without taking steel samples throughout the whole process

Abstract

The present invention relates to a method for smelting low-silicon aluminum steel without taking steel samples throughout the whole process. The finished product composition of low-carbon low-silicon aluminum steel is: 0.01% ≤ C ≤ 0.1%, Si ≤ 0.05%, Mn ≤ 0.5%, P ≥ 0.015%, S ≥ 0.012%, 0.01% ≤ Als ≤ 0.06%. The process route is: hot metal pretreatment → converter → RH → caster, and specifically includes the following steps: hot metal pretreatment, desulfurization, slag skimming and hot metal charging after desulfurization, control of desulfurization; converter control; RH control. The advantages of the present invention are: when producing low-carbon low-silicon aluminum steel, by using the whole process of hot metal pretreatment → converter → RH furnace to smelt this type of steel without taking steel samples, during the smelting of this type of steel, component analysis and judgment can be carried out according to the data in actual production, reducing the smelting cycle, saving human resources and smelting costs while ensuring the quality of molten steel and smooth production.

Description

Technical Field

[0001] The present invention relates to the field of low-carbon and low-silicon steel production, and particularly to a method for smelting low-silicon aluminum steel without taking steel samples throughout the process. Background Art

[0002] The conventional method for steel mills to adjust the composition of molten steel is the sampling method. Due to the large production volume, tight time, high labor intensity of workers in steel mills, easy damage during process sampling, slow component inspection in the laboratory, and frequent chemical analysis deviations, the conventional method sometimes fails to meet the actual on-site production, easily causing accidents such as the reduction of the casting machine speed, interruption of casting, and unqualified components.

[0003] In the prior art, the patent publication number: CN106884071B, discloses a treatment method for refining and producing low-silicon aluminum killed steel under the condition of low-temperature tapping from a converter. This invention reduces the burning loss of acid-soluble aluminum during the refining process, improves the recovery rate of aluminum-based alloys, shortens the refining cycle, improves the quality of molten steel, and improves the castability of the casting machine. However, multiple sampling detections are required in the smelting process of this invention, which affects the smooth progress of production.

[0004] The patent publication number: CN106884068B, discloses a converter refining production process for low-carbon and low-silicon aluminum killed steel. This invention is conducive to less slag smelting in the converter, increasing the converter lining life, reducing the consumption of refractory materials, reducing the oxygen content in the molten steel tapped from the converter, and increasing the scrap ratio, thereby reducing production costs. However, multiple sampling detections are required in the smelting process of this invention, resulting in high labor costs.

[0005] The patent publication number: CN115725817A, discloses a rapid desulfurization method for low-carbon and low-silicon aluminum killed steel. This invention adjusts the slag during the tapping process according to the dissolved oxygen content in the molten steel, precisely controls the addition amounts of slag-making materials and ferrosilicon aluminum, ensures that the initial slag has a suitable melting point, is conducive to reducing the total oxygen in the slag and the rapid dissolution of subsequent lime. During the heating process, different arc lengths are generated at different gears to match the slag amount, achieving submerged arc slag melting to promote the rapid dissolution of lime. During the slag-making process, the addition amounts and batches of slag-making materials are controlled to achieve rapid slag formation and desulfurization of low-carbon and low-silicon aluminum killed steel. However, the smelting cost of this invention is relatively high, and the labor intensity of workers is large.

[0006] The patent publication number: CN102534118B, discloses a method for reducing the flocculation flow of low-silicon aluminum killed steel. This invention enables continuous casting of low-silicon aluminum killed steel for more than 15 ladles without flocculation flow, greatly improving equipment productivity and product quality, and reducing casting interruption accidents. However, this invention does not explain reducing the smelting cost and the labor intensity of workers. Summary of the Invention

[0007] The purpose of the present invention is to provide a method for smelting low-silicon aluminum steel without taking steel samples throughout the process. When smelting low-silicon aluminum steel in a steel mill, the composition can be judged based on the data in actual production, saving human resources and smelting costs while ensuring the quality of molten steel and the smooth progress of production.

[0008] To achieve the above object, the present invention is realized through the following technical solutions:

[0009] A method for smelting low-silicon aluminum steel without taking steel samples throughout the process. The finished product composition of low-carbon low-silicon aluminum steel is: 0.01% ≤ C ≤ 0.1%, Si ≤ 0.05%, Mn ≤ 0.5%, P ≥ 0.015%, S ≥ 0.012%, 0.01% ≤ Als ≤ 0.06%. The process route is: hot metal pretreatment → converter → RH → caster. Specifically, it includes the following steps:

[0010] S1. Hot metal pretreatment, desulfurization. After desulfurization, slag is skimmed and hot metal is charged. Control of desulfurization:

[0011] a) If the upper limit of sulfur in the finished product of low-carbon low-silicon aluminum steel is 0.015% < [S] < 0.020%, then the desulfurization target is set to 0.008%, the lime addition amount is 1.4 - 1.6 kg / t, and the magnesium powder addition amount is 0.35 - 0.45 kg / t;

[0012] b) If the upper limit of sulfur in the finished product of low-carbon low-silicon aluminum steel is 0.012% < [S] ≤ 0.015%, then the desulfurization target is set to 0.005%, the lime addition amount is 1.8 - 2.0 kg / t, and the magnesium powder addition amount is 0.55 - 0.65 kg / t;

[0013] c) If the upper limit of sulfur in the finished product of low-carbon low-silicon aluminum steel is 0.010 < [S] ≤ 0.012%, then the desulfurization target is set to 0.003%, the lime addition amount is 2.2 - 2.4 kg / t, and the magnesium powder addition amount is 0.75 - 0.85 kg / t;

[0014] d) If the upper limit of sulfur in the finished product of low-carbon low-silicon aluminum steel is [S] ≤ 0.010%, then the desulfurization target is set to 0.001%, the lime addition amount is 2.6 - 2.8 kg / t, and the magnesium powder addition amount is 0.95 - 1.05 kg / t;

[0015] S2. Converter control:

[0016] a) Control of phosphorus:

[0017] The tapping temperature is controlled at 1670 - 1690 °C, the oxygen value at the end of the converter is ≥ 300 ppm, the addition amount of quicklime is controlled at 26 - 35 kg / t, and the total slag amount is controlled at 50 - 60 kg / t;

[0018] b) Select a converter with ≥3 bottom blowing nozzles, determine the carbon-oxygen product of the converter through the first 1 to 3 heats of steelmaking, and stably control the carbon-oxygen product below 0.003%;

[0019] c) After the converter blowing, conduct tests to measure the end-point temperature and the end-point oxygen value of the converter. Calculate the end-point carbon content of the converter through the end-point oxygen value and the carbon-oxygen product of the converter. If the end-point carbon content > 0.1% or the end-point oxygen value of the converter < 300 ppm, the converter needs to be spot-blown for oxygen supplementation, and the spot-blowing is calculated based on an increase of 10 ppm in the end-point oxygen value per second;

[0020] S3. RH control:

[0021] a) Control of the oxygen content at the end of decarburization:

[0022] When entering the station, determine the oxygen content with an oxygen-determining lance. Calculate the excess oxygen content based on the oxygen content determined when entering the station and the end-point carbon content of the converter. If the excess oxygen content < 0 ppm, carry out oxygen blowing with the oxygen lance for forced decarburization. If the excess oxygen content ≥ 0 ppm, select natural decarburization according to the temperature situation;

[0023] b) Control of aluminum:

[0024] After carrying out oxygen blowing for forced decarburization or natural decarburization, wait for 7 - 8 minutes after the main vacuum valve is opened to determine the oxygen content, and add aluminum for deoxidation according to the end-point oxygen value of the converter;

[0025] c) Control of manganese:

[0026] After the RH enters the station, calculate the manganese supplementary addition amount according to the end-point manganese content. The calculation formula is:

[0027] Manganese supplementary addition amount = Target manganese content of the finished steel grade - End-point manganese content ⑦

[0028] In formula ⑦, the unit of the manganese supplementary addition amount is %, the unit of the target manganese content of the finished steel grade is %, and the unit of the end-point manganese content is %. Estimate the end-point manganese content based on the end-point oxygen value content of the converter + the oxygen value of spot-blowing;

[0029] d) Control of carbon: Add carburizer according to the residual carbon to match the carbon composition;

[0030] e) After RH deoxidation, move out after matching carbon, manganese, and aluminum, and take the middle-package finished product sample during continuous casting.

[0031] In step S2, the calculation formula for the end-point carbon content of the converter is:

[0032] End-point carbon content of the converter = Carbon-oxygen product of the previous heat / End-point oxygen value of the converter ①

[0033] In formula ①, the unit of the end-point carbon content of the converter is %, and the unit of the end-point oxygen value of the converter is %.

[0034] In step S3, the calculation formula for the excess oxygen content is:

[0035] Excess oxygen content = oxygen determination value - (converter end-point carbon content - 70) × δ - 150 ②

[0036] In formula ②, δ represents the oxygen coefficient for decarburization, and the value of δ is as follows:

[0037] If the converter end-point carbon content C ≤ 300 ppm, δ = 0.75;

[0038] If 500 ≥ C > 300 ppm for the converter end-point carbon content, δ = 0.70;

[0039] If 600 ≥ C > 500 ppm for the converter end-point carbon content, δ = 0.65;

[0040] If the converter end-point carbon content C > 600 ppm, δ = 0.80.

[0041] In step S3, oxygen blowing is used for forced decarburization, and the calculation formula is:

[0042] Oxygen blowing forced decarburization amount = excess oxygen content × molten steel weight / 914 ③

[0043] In formula ③, the unit of the oxygen blowing forced decarburization amount is Nm3, the excess oxygen content is ppm, and the unit of the molten steel weight is t.

[0044] In step S3, aluminum addition is carried out according to the converter end-point oxygen value, and the calculation formula is:

[0045] Aluminum addition amount = deoxidized aluminum + steel grade component aluminum addition amount kg ④

[0046] Deoxidized aluminum = 0.0016 × converter end-point oxygen value × molten steel weight ⑤

[0047] In formulas ④ and ⑤, the unit of the aluminum addition amount is kg, the unit of the deoxidized aluminum is kg, and the unit of the steel grade component aluminum addition amount is kg.

[0048] In step S3, the end-point manganese content is estimated as follows:

[0049] If the converter end-point oxygen value content ≤ 200 ppm, the end-point manganese content = 0.1%;

[0050] If the converter end-point oxygen value content is between 201 and 400, the end-point manganese content = 0.08%;

[0051] If the converter end-point oxygen value content is between 401 and 600, the end-point manganese content = 0.06%;

[0052] If the converter end-point oxygen value content ≥ 600, the end-point manganese content = 0.05%.

[0053] In step S3, according to the residual carbon, a carburizer is added to supplement the carbon element to adjust the carbon composition. The calculation formula is as follows:

[0054] Carbon addition amount = Target carbon content of finished steel grade - Residual carbon ⑥

[0055] In formula ⑥, the unit of the carbon addition amount is %, the unit of the target carbon content of the finished steel grade is %, the unit of the residual carbon is %, and the value range of the residual carbon is 0.002% - 0.008%.

[0056] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0057] When producing low-carbon and low-silicon aluminum steel, by adopting the smelting process of hot metal pretreatment → converter → RH furnace without taking steel samples throughout the process, during the smelting of such steel grades, the composition analysis and judgment can be carried out according to the data in actual production, reducing the smelting cycle, saving human resources and smelting costs while ensuring the quality of molten steel and the smooth progress of production. Specific embodiments

[0058] The present invention will be described in detail below, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0059] A method for smelting low-silicon aluminum steel without taking steel samples throughout the process. The finished product composition of low-carbon and low-silicon aluminum steel is: 0.01% ≤ C ≤ 0.1%, Si ≤ 0.05%, Mn ≤ 0.5%, P ≥ 0.015%, S ≥ 0.012%, 0.01% ≤ Als ≤ 0.06%. The process route is: hot metal pretreatment → converter → RH → caster, which specifically includes the following steps:

[0060] S1. Hot metal pretreatment, desulfurization. After desulfurization, slag is skimmed and hot metal is charged. The control of desulfurization:

[0061] a) If the upper limit of sulfur in the finished product of low-carbon and low-silicon aluminum steel is 0.015% < [S] < 0.020%, then the desulfurization target is set to 0.008%, the lime addition amount is 1.4 - 1.6 kg / t, and the magnesium powder addition amount is 0.35 - 0.45 kg / t;

[0062] b) If the upper limit of sulfur in the finished product of low-carbon and low-silicon aluminum steel is 0.012% < [S] ≤ 0.015%, then the desulfurization target is set to 0.005%, the lime addition amount is 1.8 - 2.0 kg / t, and the magnesium powder addition amount is 0.55 - 0.65 kg / t;

[0063] c) If the upper limit of sulfur in the finished product of low-carbon and low-silicon aluminum steel is 0.010 < [S] ≤ 0.012%, then the desulfurization target is set to 0.003%, the lime addition amount is 2.2 - 2.4 kg / t, and the magnesium powder addition amount is 0.75 - 0.85 kg / t;

[0064] d) If the upper limit of sulfur in the finished product of low-carbon and low-silicon aluminum steel is [S] ≤ 0.010%, then the desulfurization target is set at 0.001%, the lime addition is 2.6 - 2.8 kg / t, and the magnesium powder addition is 0.95 - 1.05 kg / t.

[0065] S2. Converter control:

[0066] a) Control of phosphorus:

[0067] The tapping temperature is controlled at 1670 - 1690 °C, the oxygen value at the end of the converter is ≥ 300 ppm, the addition of quicklime is controlled at 26 - 35 kg / t, and the total slag amount is controlled at 50 - 60 kg / t;

[0068] b) Select a converter with a bottom blowing quantity of ≥ 3, and determine the carbon-oxygen product of the converter through the first 1 - 3 heats of steelmaking. The carbon-oxygen product is stably controlled below 0.003%;

[0069] c) After the converter blowing, conduct tests to measure the end temperature and the oxygen value at the end of the converter. Calculate the carbon content at the end of the converter through the oxygen value at the end of the converter and the carbon-oxygen product. The formula for calculating the carbon content at the end of the converter is:

[0070] Carbon content at the end of the converter = Carbon-oxygen product of the previous heat / Oxygen value at the end of the converter ①

[0071] In formula ①, the unit of the carbon content at the end of the converter is %, and the unit of the oxygen value at the end of the converter is %.

[0072] If the carbon content at the end > 0.1% or the oxygen value at the end of the converter < 300 ppm, the converter needs to be spot-blown for oxygen supplementation, and the oxygen value at the end increases by 10 ppm per second during spot-blowing;

[0073] S3. RH control:

[0074] a) Control of oxygen at the end of decarburization:

[0075] Determine the oxygen content by the oxygen-determining lance when entering the station. Calculate the excess oxygen content based on the oxygen value determined when entering the station and the carbon content at the end of the converter. If the excess oxygen content < 0 ppm, blow oxygen with the oxygen lance for forced decarburization. If the excess oxygen content ≥ 0 ppm, select natural decarburization according to the temperature situation;

[0076] Among them, the formula for calculating the excess oxygen content is:

[0077] Excess oxygen content = Oxygen value determined - (Carbon content at the end of the converter - 70) × δ - 150 ②

[0078] In formula ②, δ represents the oxygen coefficient for decarburization, and the value of δ is:

[0079] If the carbon content C at the end of the converter is ≤ 300 ppm, δ = 0.75; if the carbon content C at the end of the converter is 500 ≥ C > 300 ppm, δ = 0.70; if the carbon content C at the end of the converter is 600 ≥ C > 500 ppm, δ = 0.65; if the carbon content C at the end of the converter is > 600 ppm, δ = 0.80;

[0080] Among them, for forced decarburization by oxygen blowing, the calculation formula is:

[0081] Forced decarburization amount by oxygen blowing = Excess oxygen content × Molten steel amount / 914 ③

[0082] In formula ③, the unit of the forced decarburization amount by oxygen blowing is Nm3, the excess oxygen content is ppm, and the unit of the molten steel amount is t;

[0083] b) Control of aluminum:

[0084] After forced decarburization by oxygen blowing or natural decarburization, oxygen is determined 7 - 8 minutes after the main vacuum valve is opened, and aluminum is added for deoxidation and calming according to the oxygen value at the end of the converter; among them, the calculation formula for adding aluminum according to the oxygen value at the end of the converter is:

[0085] Aluminum addition amount = Deoxidized aluminum + Steel grade component aluminum addition amount kg ④

[0086] Deoxidized aluminum = 0.0016 × Oxygen value at the end of the converter × Molten steel amount ⑤

[0087] In formulas ④ and ⑤, the unit of the aluminum addition amount is kg, the unit of the deoxidized aluminum is kg, and the unit of the steel grade component aluminum addition amount is kg.

[0088] c) Control of manganese:

[0089] After entering RH, the manganese supplementary addition amount is calculated according to the manganese content at the end, and the calculation formula is:

[0090] Manganese supplementary addition amount = Target manganese content of the finished steel grade - Manganese content at the end ⑥

[0091] In formula ⑥, the unit of the manganese supplementary addition amount is %, the unit of the target manganese content of the finished steel grade is %, the unit of the manganese content at the end is %, and the manganese content at the end is estimated according to the oxygen value content at the end of the converter + Point oxygen blowing value;

[0092] Among them, for estimating the manganese content at the end, the content is as follows:

[0093] If the oxygen value content at the end of the converter is ≤ 200 ppm, the manganese content at the end = 0.1%; if the oxygen value content at the end of the converter is between 201 - 400, the manganese content at the end = 0.08%; if the oxygen value content at the end of the converter is between 401 - 600, the manganese content at the end = 0.06%; if the oxygen value content at the end of the converter is ≥ 600, the manganese content at the end = 0.05%;

[0094] d) Control of carbon: Add carburizer to supplement carbon element according to the residual carbon, and match the carbon composition. The calculation formula is:

[0095] Carbon addition amount = Target carbon content of finished steel grade - Residual carbon ⑦

[0096] In formula ⑦, the unit of carbon addition amount is %, the unit of target carbon content of finished steel grade is %, the unit of residual carbon is %, and the value range of residual carbon is 0.002% - 0.008%.

[0097] e) After RH degassing, mix carbon, manganese and aluminum and then remove them. Take the middle package finished product sample during continuous casting machine casting.

[0098] The following examples are implemented on the premise of the technical solution of the present invention, and detailed implementation methods and specific operation processes are given. However, the protection scope of the present invention is not limited to the following examples. The methods used in the following examples are all conventional methods unless otherwise specified.

[0099]

Example 1

[0100] A method for smelting low-silicon aluminum steel without taking steel samples throughout the process. The process route is: hot metal pretreatment → converter → RH → continuous casting machine. The composition requirements for a certain steel grade smelted in a 260-ton converter are 0.035% ≤ C ≤ 0.06%, Si ≤ 0.03%, 0.15% ≤ Mn ≤ 0.22%, P ≤ 0.020%, S ≤ 0.015%, 0.02% ≤ Als ≤ 0.045%. The specific steps are as follows:

[0101] Step S1, Hot metal pretreatment:

[0102] According to the S content required for the finished product, desulfurize at 0.005%, add 500 kg of lime and 150 kg of magnesium powder. After desulfurization, skim the slag and pour in the hot metal.

[0103] Step S2, Use 4 bottom-blown converters for smelting. During the smelting process, add 7500 kg of quicklime, the total slag amount is 13300 kg, the end-point temperature is 1685 °C, the oxygen value at the end of the converter is 0.0398%, and the carbon-oxygen product of the previous few furnaces during smelting is about 0.0023. Calculate the tapping carbon to be 0.0578%;

[0104] Step S3, After the RH enters the station, the oxygen value at the entrance is 0.0328%. Calculate the excess oxygen content to be -152 ppm. Since the excess oxygen content < 0 ppm, forced decarburization is carried out, and the oxygen blowing amount for forced decarburization is 44 m 3 ;

[0105] Step S4, Determine the oxygen after 7 minutes and 33 seconds of decarburization. The oxygen value at the end of the converter is 156 ppm. A total of 185 kg of aluminum wire segments are added according to the oxygen value at the end of the converter, and the estimated carbon component is 0.007%.

[0106] Step S5: Based on the oxygen value at the end of the converter blowing, the residual manganese is estimated to be 0.08%, and according to the requirement of the finished product Mn, 400 kg of ferromanganese is added. Since the carbon content of ferromanganese is 7%, 80 kg of carburizer is added.

[0107] Step S6: After RH treatment, casting is carried out on the machine. A middle ladle sample is taken, with C = 0.044%, Si = 0.009%, Mn = 0.192%, P = 0.016%, S = 0.013%, and all the components are qualified.

[0108]

Example 2

[0109] A method for smelting low-silicon aluminum steel without taking steel samples in the whole process, with the process route: hot metal pretreatment → converter → RH → caster. For a certain steel grade smelted in a 260-ton converter, the component requirements are 0.01% ≤ C ≤ 0.03%, Si ≤ 0.03%, 0.18% ≤ Mn ≤ 0.25%, P ≤ 0.018%, S ≤ 0.013%, 0.01% ≤ Als ≤ 0.05%, including the following steps:

[0110] Step S1: Hot metal pretreatment: According to the S content requirement of the finished product, desulfurization is carried out at 0.005%, 520 kg of lime and 155 kg of magnesium powder are added. After desulfurization, the slag is skimmed and the hot metal is charged.

[0111] Step S2: Four bottom-blown converters are used for smelting. During the smelting process, 8000 kg of quicklime is added, the total slag amount is 14500 kg, the end-point temperature is 1683 °C, the oxygen value at the end of the converter blowing is 0.0538%, and the carbon-oxygen product of the previous few furnaces is about 0.0023. The tapping carbon is calculated to be 0.0427%.

[0112] Step S3: After the RH station entry, the oxygen value at the station entry is 0.0457%, the excess oxygen is calculated to be 57 ppm, and the excess oxygen content > 0 ppm, so natural decarburization is adopted.

[0113] Step S4: Oxygen is determined after 7 minutes and 23 seconds of decarburization. The oxygen value at the end of the converter blowing is 176 ppm. A total of 193 kg of aluminum wire segments are added according to the oxygen value at the end of the converter blowing, and the carbon component is estimated to be 0.006%.

[0114] Step S5: Based on the oxygen value at the end of the converter blowing, the residual manganese is estimated to be 0.06%, and according to the requirement of the finished product Mn, 570 kg of ferromanganese is added. Since the carbon content of ferromanganese is 7%, no carburizer is added.

[0115] Step S6: After RH treatment, casting is carried out on the machine. A middle ladle sample is taken, with C = 0.023%, Si = 0.011%, Mn = 0.215%, P = 0.014%, S = 0.013%, and all the components are qualified.

[0116] When producing low-carbon and low-silicon aluminum steel, the present invention adopts the smelting process of hot metal pretreatment → converter → RH furnace without taking steel samples for the whole process of smelting such steel grades. When smelting such steel grades, component analysis and judgment can be carried out according to the data in actual production, reducing the smelting cycle, saving human resources and smelting costs, while ensuring the quality of molten steel and the smooth progress of production.

Claims

1. A method for smelting low-silicon aluminum steel without taking steel samples throughout the process, characterized in that The finished product composition of low-carbon and low-silicon aluminum steel is: 0.01% ≤ C ≤ 0.1%, Si ≤ 0.05%, Mn ≤ 0.5%, P ≥ 0.015%, S ≥ 0.012%, 0.01% ≤ Als ≤ 0.06%. The process route is: hot metal pretreatment → converter → RH → caster, and it specifically includes the following steps: S1. Hot metal pretreatment, desulfurization, slag skimming and hot metal charging after desulfurization. The control of desulfurization: a) If the sulfur content of the finished low-carbon and low-silicon aluminum steel is 0.015% < [S] < 0.020%, then the desulfurization target is set at: 0.008%, the lime addition amount is: 1.4 - 1.6 kg / t, and the magnesium powder addition amount is 0.35 - 0.45 kg / t; b) If the sulfur content of the finished low-carbon and low-silicon aluminum steel is 0.012% < [S] ≤ 0.015%, then the desulfurization target is set at: 0.005%, the lime addition amount is: 1.8 - 2.0 kg / t, and the magnesium powder addition amount is 0.55 - 0.65 kg / t; c) If the sulfur content of the finished low-carbon and low-silicon aluminum steel is 0.010% < [S] ≤ 0.012%, then the desulfurization target is set at: 0.003%, the lime addition amount is: 2.2 - 2.4 kg / t, and the magnesium powder addition amount is 0.75 - 0.85 kg / t; d) If the sulfur content of the finished low-carbon and low-silicon aluminum steel is [S] ≤ 0.010%, then the desulfurization target is set at: 0.001%, the lime addition amount is: 2.6 - 2.8 kg / t, and the magnesium powder addition amount is 0.95 - 1.05 kg / t; S2. Converter control: a) Control of phosphorus: The tapping temperature is controlled at 1670 - 1690 °C, the oxygen value at the end of the converter is ≥ 300 ppm, the addition amount of quicklime is controlled at 26 - 35 kg / t, and the total slag amount is controlled at 50 - 60 kg / t; b) Select a converter with ≥ 3 bottom blowing nozzles, determine the carbon-oxygen product of the converter through the first 1 - 3 heats of steelmaking, and stably control the carbon-oxygen product below 0.003%; c) After the converter blowing, conduct tests to measure the end temperature and the oxygen value at the end of the converter. Calculate the carbon content at the end of the converter through the oxygen value at the end of the converter and the carbon-oxygen product. If the end carbon content > 0.1% or the oxygen value at the end of the converter < 300 ppm, the converter needs to be spot-blown for oxygen supplementation, and the oxygen supplementation by spot blowing is calculated at an increase of 10 ppm per second for the oxygen value at the end; S3. RH control: a) Control of oxygen at the end of decarburization: Determine oxygen by an oxygen-determining lance when entering the station. Calculate the excess oxygen content based on the oxygen value determined when entering the station and the carbon content at the end of the converter. If the excess oxygen content < 0 ppm, conduct oxygen lance blowing for forced decarburization. If the excess oxygen content ≥ 0 ppm, select natural decarburization according to the temperature situation; b) Control of aluminum: After conducting oxygen lance blowing for forced decarburization or natural decarburization, determine oxygen 7 - 8 minutes after the main vacuum valve is opened, and add aluminum for calming according to the oxygen value at the end of the converter; c) Control of manganese: After entering the RH station, calculate the manganese supplementary addition amount based on the manganese content at the end. The calculation formula is: Manganese supplementary addition amount = Target manganese content of the finished steel grade - Manganese content at the end ⑦; In formula ⑦, the unit of the manganese supplementary addition amount is %, the unit of the target manganese content of the finished steel grade is %, and the unit of the manganese content at the end is %. Estimate the manganese content at the end based on the oxygen value at the end of the converter + the oxygen value of spot blowing; d) Control of carbon: Add carburizer according to the residual carbon to adjust the carbon composition. e) After RH degassing, adjust the carbon, manganese, and aluminum, then remove the molten steel. Take the tundish finished product sample during continuous casting.

2. The method for smelting low-silicon aluminum steel without taking steel samples in the whole process according to claim 1, wherein In step S2, the formula for calculating the converter end-point carbon content is as follows: Converter end-point carbon content = carbon-oxygen product of the previous heat / converter end-point oxygen value ①; In formula ①, the unit of the converter end-point carbon content is %, and the unit of the converter end-point oxygen value is %.

3. A method for smelting low-silicon aluminum steel without taking steel samples throughout the process according to claim 1, characterized in that, In step S3, the formula for calculating the excess oxygen content is as follows: Excess oxygen content = oxygen measurement value - (converter end-point carbon content - 70) × δ - 150 ②; In formula ②, δ represents the oxygen coefficient for decarburization, and the value of δ is: If the converter end-point carbon content C ≤ 300 ppm, δ = 0.75; If 500 ≥ C > 300 ppm for the converter end-point carbon content, δ = 0.70; If 600 ≥ C > 500 ppm for the converter end-point carbon content, δ = 0.65; If the converter end-point carbon content C > 600 ppm, δ = 0.

80.

4. A method for smelting low-silicon aluminum steel without taking steel samples throughout the process according to claim 1, characterized in that, In step S3, the formula for calculating the oxygen blowing for forced decarburization is as follows: Oxygen blowing forced decarburization amount = excess oxygen content × molten steel weight / 914 ③; In Formula ③, the unit of the oxygen-blowing forced decarburization amount is Nm 3 , the unit of the excess oxygen content is ppm, and the unit of the molten steel amount is t.

5. A method for smelting low-silicon aluminum steel without taking steel samples throughout the process, as claimed in claim 1, wherein In step S3, the formula for adding aluminum according to the converter end-point oxygen value is as follows: Aluminum addition amount = deoxidizing aluminum + aluminum addition amount for steel grade composition ④; Deoxidizing aluminum = 0.0016 × converter end-point oxygen value × molten steel weight ⑤; In formulas ④ and ⑤, the unit of the aluminum addition amount is kg, the unit of deoxidizing aluminum is kg, and the unit of the aluminum addition amount for steel grade composition is kg.

6. A method for smelting low-silicon aluminum steel without taking steel samples throughout the process, as claimed in claim 1, wherein ​ ​ ​ ​ ​ 7. A method for smelting low-silicon aluminum steel without taking steel samples throughout the process, as claimed in claim 1, wherein ​ ​ ​