Calculation method of acid soluble aluminum in cold heading steel

Abstract

The present application relates to the technical field of steel smelting, and in particular to a cold heading steel acid-soluble aluminum calculation method, which can calculate the content of cold heading steel acid-soluble aluminum in advance according to the process parameters of the smelting process and the composition and temperature of sample one and the temperature of sample two, so as to avoid the problems of aluminum supplement or aluminum content exceeding the standard in the late process, and further to prepare cold heading steel meeting the quality requirements.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of steel smelting, in particular to a cold heading steel acid-soluble aluminum calculation method. BACKGROUND

[0002] Cold heading steel includes SWRCH6A, SWRCH8A, SWRCH10A, SWRCH15A, SWRCH18A, SWRCH22A, etc., and usually adopts converter-LF furnace-continuous casting process.

[0003] Stable control of acid-soluble aluminum is one of the evaluation standards for the quality of cold heading steel. To prepare cold heading steel meeting the requirements, it is necessary to strictly control the acid-soluble aluminum content before sample two, so as to avoid aluminum addition after sample two, thereby reducing the generation of aluminum oxide inclusions, prolonging the soft blowing purification time of molten steel, and thus improving the purity and quality of molten steel.

[0004] However, the cold heading steel smelting process provided by the related art is difficult to control acid-soluble aluminum. Since the process requires stirring with large argon gas for 3-5 minutes after the refining sample one result is obtained, the operator cannot accurately calculate the acid-soluble aluminum content in the molten steel, and basically first roughly adjusts the acid-soluble aluminum after the refining sample one is obtained, and controls it at 0.030%-0.070%. After stirring, sample two is taken again, and then the acid-soluble aluminum is adjusted again according to the sample two, and is controlled at 0.045%-0.055%. After the acid-soluble aluminum is adjusted, it is waited for 5 minutes before the calcium wire is fed for soft blowing. In this way, if the acid-soluble aluminum content in the molten steel can be known at the time of sample two, the acid-soluble aluminum can be immediately supplemented, and the waiting time for the sample two test can be reduced by about 6 minutes, and the aluminum addition and waiting time after the sample two is obtained can be reduced by 10 minutes, which is equivalent to saving 16 minutes for soft blowing and increasing the soft blowing purification time of the molten steel.

[0005] Therefore, a method is needed to quickly calculate the acid-soluble aluminum content in the molten steel at the time of sample two through process and operation. SUMMARY

[0006] The present application relates to the technical field of steel smelting, in particular to a cold heading steel acid-soluble aluminum calculation method.

[0007] The present application is implemented as follows:

[0008] The present application provides a cold heading steel acid-soluble aluminum calculation method, comprising:

[0009] The acid-soluble aluminum concentration after the slag is sent to the electric furnace and argon stirring is calculated according to the following formula,

[0010] The concentration of acid-soluble aluminum in the steel = the estimated concentration of acid-soluble aluminum in the steel - the concentration of acid-soluble aluminum burned by the total slag amount - the concentration of acid-soluble aluminum burned by the stirring temperature drop - the concentration of acid-soluble aluminum burned by the stirring time; wherein,

[0011] The estimated concentration of acid-soluble aluminum in the steel = the concentration of acid-soluble aluminum in sample one taken during the electrically-conducting slag process + the concentration of acid-soluble aluminum increased by the aluminum wire fed during the electrically-conducting slag process - the concentration of acid-soluble aluminum lost during the electrically-conducting slag process.

[0012] The concentration of acid-soluble aluminum burned by the total slag amount = [(the weight of aluminum slag added in the LF refining + the weight of fluorite added in the LF refining) / (the weight of lime added in the LF refining + the weight of lime added in the converter tapping + the weight of synthetic slag added in the LF refining)] x 0.0021%.

[0013] The concentration of acid-soluble aluminum burned by the stirring temperature drop = [(the temperature of sample one taken during the electrically-conducting slag process + the temperature increased by the continued electrically-conducting temperature rise after sample one is taken - the temperature of sample two taken) / (the argon blowing stirring time before sample two is taken / 60)] x 0.0003%.

[0014] The concentration of acid-soluble aluminum burned by the stirring time = (the argon blowing stirring time before sample two is taken / 10) x 0.001%.

[0015] In an optional embodiment, the calculation method of acid-soluble aluminum in the cold upsetting steel is used for a smelting process including the converter tapping, the argon station aluminum feeding, the LF refining, the electrically-conducting slag and the argon blowing of the cold upsetting steel; wherein,

[0016] The converter tapping includes: adding aluminum iron according to the terminal oxygen content.

[0017] In an optional embodiment, the amount of aluminum iron added is calculated according to the standard of 2 ppm of aluminum iron deoxidation per 0.8-1.2 kg of aluminum iron, wherein the aluminum content of the aluminum iron is 45%-55%, and the recovery rate is 65%-75%.

[0018] In an optional embodiment, the process of the converter tapping further includes adding lime.

[0019] In an optional embodiment, the step of the argon station aluminum feeding includes: feeding the aluminum content to 0.04%-0.06% by mass percentage.

[0020] In an optional embodiment, the step of the LF refining includes: adding synthetic slag, fluorite, lime and aluminum slag, and argon blowing stirring, wherein during the addition of the slag, the standard of the argon blowing is 95-105 cubic meters / hour, and after the addition of the slag, the standard of the argon blowing is adjusted to 40-60 cubic meters / hour.

[0021] In an optional embodiment, the step of the electrically-conducting slag includes:

[0022] When the temperature of the molten steel at the station is less than 1561℃, the 8th gear power supply slag is used;

[0023] When the temperature of the molten steel at the station is 1561-1570℃, the 9th gear power supply slag is used;

[0024] When the temperature of the molten steel at the station is 1571-1580℃, the 10th gear power supply slag is used;

[0025] When the temperature of the molten steel at the station is greater than 1580℃, the 11th gear power supply slag is used;

[0026] According to the acid-soluble aluminum content of the argon station sample, the aluminum wire is fed, wherein the aluminum content is increased by 0.001% per 5 meters of the aluminum wire.

[0027] In an optional embodiment, the power supply slag step further comprises: after the aluminum wire is fed, at least one gear position of 11th gear, 10th gear, 9th gear, 8th gear, 7th gear, 6th gear, 5th gear, 4th gear, 3rd gear, and 2nd gear is selected according to the temperature to increase the temperature until the temperature reaches 1565-1570℃, sample one is taken, and the temperature is measured.

[0028] In an optional embodiment, the power supply slag step further comprises: after sample one is taken, the temperature is continuously increased and the time for increasing the temperature is controlled within 300 seconds, and the flow rate of argon blowing during the temperature increasing process is maintained at 40-60 cubic meters / hour.

[0029] In an optional embodiment, the power supply slag step further comprises: according to the composition of sample one, the acid-soluble aluminum content is adjusted to 0.073-0.075%, while argon blowing and stirring are performed, and the argon blowing flow rate is controlled at 95-105 cubic meters / hour, then sample two is taken, and the temperature is measured.

[0030] The present application includes the following beneficial effects:

[0031] The embodiment of the present application provides a cold upsetting steel acid-soluble aluminum calculation method, which can calculate the cold upsetting steel acid-soluble aluminum content in advance according to some process parameters in the smelting process, the composition and temperature of sample one, and the temperature of sample two; in this way, after the composition of sample one is obtained, the cold upsetting steel acid-soluble aluminum content calculated in advance is adjusted and controlled through the adjustment of the acid-soluble aluminum content and the temperature measurement after stirring, so that the problem that the acid-soluble aluminum content is detected only through sample two and needs to be supplemented with aluminum when the acid-soluble aluminum content is lower than the requirement, which leads to the increase of the process time and the difficulty of processing inclusions, or the problem that the acid-soluble aluminum content is too high and exceeds the requirement after sample two is taken is improved. DETAILED DESCRIPTION

[0032] In order to make the purposes, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below. If specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by manufacturers are adopted. If manufacturers of reagents or instruments are not specified, all are conventional products that can be purchased in the market.

[0033] The general process of cold heading steel generally includes: converter-LF furnace-continuous casting, and one of the process difficulties for preparing qualified cold heading steel is the control of acid-soluble aluminum.

[0034] In the related art, taking SWRCH22A as an example and taking the tapping amount as 120 tons, 300-500 kg of aluminum iron is added during tapping of the converter, and 100-200 kg of aluminum slag is added in the LF furnace, so that there is a high acid-soluble aluminum and aluminum oxide in the steel, and the refining process requires 3-5 minutes of argon stirring, during which a large amount of acid-soluble aluminum in the steel will be oxidized or enter the slag, and the process is affected by many factors such as molten steel temperature, slag composition, slag amount, argon stirring time, stirring intensity, and deoxidation degree, so that the acid-soluble aluminum is difficult to accurately control.

[0035] On the other hand, the refining time of the above steel grade is 35 minutes, and the control of acid-soluble aluminum needs to be completed within 35 minutes, because the steel grade standard has strict requirements on the aluminum wire feeding time and soft blowing time, that is, after the aluminum wire is fed, 10 minutes are waited for calcium wire feeding, and the soft blowing time is required to be greater than 20 minutes, that is, 30 minutes are waited after the aluminum wire is fed before leaving the station. For the LF furnace, the refining operation process is as follows: molten steel enters the station to the treatment position (2-2.5 minutes), adds slag to the furnace cover (2-2.5 minutes), melts the slag, sends electricity and heats up for 8-11 minutes, takes sample one and analyzes the composition (6-7 minutes), adjusts the composition and stirs with argon (3-5 minutes), takes sample two and analyzes the composition (6-7 minutes), and at this time, the total time (27-35 minutes) is controlled with the minimum time, so that the aluminum needs to be adjusted to the range at one time after the sample one composition is obtained, otherwise if the acid-soluble aluminum is not enough, the aluminum wire needs to be fed again, and the calcium wire can be fed only after 10 minutes, so that the refining time is definitely more than 35 minutes, and thus the process time is increased and the difficulty is increased.

[0036] The present application provides a kind of cold heading steel acid-soluble aluminum calculation method, the concentration of acid-soluble aluminum after sending power slag and argon blowing stirring is calculated according to the following formula,

[0037] The concentration of acid-soluble aluminum = the concentration of estimated acid-soluble aluminum in steel - the concentration of total slag affecting acid-soluble aluminum burn loss - the concentration of stirring temperature drop affecting acid-soluble aluminum burn loss - the concentration of stirring time affecting acid-soluble aluminum burn loss;Wherein,

[0038] The estimated concentration of acid-soluble aluminum in the steel = the concentration of acid-soluble aluminum in sample one taken during the electric smelting slag process + the concentration of acid-soluble aluminum increased by the aluminum wire fed during the electric smelting slag process - the concentration of acid-soluble aluminum lost during the electric smelting slag process;

[0039] The concentration of acid-soluble aluminum loss affected by the total slag amount = [(the weight of aluminum slag added in the LF refining + the weight of fluorite added in the LF refining) / (the weight of lime added in the LF refining + the weight of lime added in the converter tapping + the weight of synthetic slag added in the LF refining)] * 0.0021%;

[0040] The concentration of acid-soluble aluminum loss affected by the stirring temperature drop = [(the temperature of sample one taken during the electric smelting slag process + the temperature increased by the continued electric heating after sample one is taken - the temperature of sample two taken) / (the argon stirring time before sample two is taken / 60)] * 0.0003%;

[0041] The concentration of acid-soluble aluminum loss affected by the stirring time = (the argon stirring time before sample two is taken / 10) * 0.001%.

[0042] Therefore, the calculation method of the present application can calculate the content of acid-soluble aluminum in the cold upsetting steel in advance according to some process parameters of the smelting process and the composition and temperature of sample one and the temperature of sample two; in this way, after the composition of sample one is obtained during the smelting process, the content of acid-soluble aluminum in the cold upsetting steel calculated in advance is obtained through acid dissolution and temperature measurement after stirring, and is controlled and improved, so that the problem that the content of acid-soluble aluminum is not known until sample two is taken, and aluminum needs to be added when the content of acid-soluble aluminum is detected to be lower than the requirement, and the process time is increased and the difficulty of treating inclusions is increased, or the problem that the content of acid-soluble aluminum is detected to be too high and exceeds the requirement after sample two is taken.

[0043] It should be noted that the unit of stirring time is second, and the unit of material weight is kg (kilogram).

[0044] The cold upsetting steel acid-soluble aluminum calculation method of the present application is used for smelting processes including converter tapping, argon station aluminum feeding, LF refining, electric smelting slag and argon blowing of cold upsetting steel.

[0045] The step of converter tapping includes: adding aluminum iron according to the terminal oxygen content to perform deoxidation.

[0046] Further, the amount of aluminum iron added is calculated according to the standard of 2ppm deoxidation per 0.8-1.2kg of aluminum iron, wherein the aluminum content of the aluminum iron is 45%-55%, and the recovery rate is 65%-75%.

[0047] It should be noted that, according to the calculation of 0.8-1.2 kg aluminum iron deoxidation 2 ppm oxygen, mainly because the steel needs to meet the requirement of acid-soluble aluminum reaching 0.025%-0.045%, so the steel needs to have surplus aluminum, increase the acid-soluble aluminum in the steel, and prepare for subsequent refining slagging and deoxidation. That is to say, the purpose of adding aluminum iron is not only deoxidation, but also to increase the surplus aluminum, so as to increase the acid-soluble aluminum in the molten steel through the surplus aluminum, so as to ensure that the acid-soluble aluminum in the process of tapping reaches more than 0.02%, so as to achieve the purpose of complete deoxidation. If the acid-soluble aluminum in the process of tapping is less than 0.02%, the molten steel cannot be completely deoxidized.

[0048] Further, the process of converter tapping also includes adding lime.

[0049] It should be noted that the amount of aluminum iron and lime can be selected according to the corresponding standard and needs; for example, taking 120 tons of tapping amount as an example, 1 kg of aluminum iron can be calculated for deoxidation of 2 ppm, and 500 kg of lime is added when the tapping is 30-40 tons.

[0050] After tapping, the molten steel is transferred to the argon station for sampling. According to the composition, the content of aluminum can be matched to 0.04%-0.06% by mass percentage; preferably, 0.048-0.052%.

[0051] Then the molten steel is sent to the LF furnace; the steps of LF refining include adding synthetic slag, fluorite, lime and aluminum slag, and blowing argon to stir.

[0052] It should be noted that the amount of the above-mentioned slag can be selected as needed, and for example, taking 120 tons of tapping amount as an example, the addition amount of synthetic slag is 495-505 kg, 0-200 kg of fluorite is added after the addition of synthetic slag, 340-360 kg of lime and 95-170 kg of aluminum slag (preferably 100-150 kg) is added after the addition of fluorite.

[0053] It should be noted that since the addition amount of aluminum slag is in the range of 95-170 kg, and the addition amount of fluorite is controlled to be 0-200 kg, within this range, with the increase of the addition amount of the two, the slag gradually changes from thick to thin, and the acid-soluble aluminum loss coefficient (%) gradually increases. However, if the amount of aluminum slag is added to 250 kg or more, since the aluminum slag usually contains 37%-43% of aluminum, if the addition amount of aluminum slag is large, it means that more aluminum is added to the steel or slag, even if the slag is very thin, the acid-soluble aluminum in the molten steel will be high, and the acid-soluble aluminum loss coefficient % will be small. According to the above-mentioned range of adding fluorite and aluminum slag and the like, the molten steel can have good fluidity, and the good fluidity can maximize the adsorption of inclusions in the molten steel. According to the method of the present application, the content of calcium oxide in the slag is 53%-57%, and the content of aluminum in the slag is 24%-31%, so the calcium oxide:aluminum oxide in the slag can be controlled in the ideal range of 1.8-2.2.

[0054] It should be noted that the order of adding fluorite and synthetic slag can be interchanged, but lime and aluminum slag should be added later. If the aluminum slag is added first, part of the aluminum will enter the molten steel, and the aluminum in the subsequent slag will be less, which will affect the deoxidation of the slag. If the deoxidation of the slag is not saturated, the accuracy of the final result of the formula calculation will be affected.

[0055] Further, during the process of adding slag, the standard of argon blowing is 95-105 cubic meters / hour, and the standard of argon blowing is adjusted to 40-60 cubic meters / hour after the addition of slag. If the argon flow is small when the slag is added, it will affect the melting rate of the slag and the mixing degree of aluminum in the slag, because the aluminum slag contains a certain amount of binder, which will make the whole slag foam and expand, so that the aluminum is mixed into the slag body, so it is necessary to control the flow of argon blowing to be larger. However, within 1 minute after the addition of slag, the argon flow should be adjusted to be small, because the foaming time of the slag is short, and the gas will be quickly discharged from the slag, the time is usually not more than 100 seconds, if the argon flow is not small, it will accelerate the burning loss of aluminum and affect the accuracy of the formula calculation result.

[0056] After LF refining, power feeding slag can be carried out, which includes: after power feeding at 11-8, according to the acid-soluble aluminum content of argon station sample, feeding aluminum wire; specifically, when the temperature of molten steel to the station is less than 1561℃, using 8 power feeding slag; when the temperature of molten steel to the station is 1561-1570℃, using 9 power feeding slag; when the temperature of molten steel to the station is 1571-1580℃, using 10 power feeding slag; when the temperature of molten steel to the station is greater than 1580℃, using 11 power feeding slag.

[0057] In 11-8, the power feeding time of any one of them can be 180-200 seconds; the amount of feeding aluminum wire can be calculated according to increasing 0.001% of aluminum for every feeding of about 5 meters of aluminum wire, and the content of aluminum is adjusted to 0.068%-0.072%.

[0058] It should be noted that because the size of the just added slag is relatively large, part of the aluminum is not completely mixed into the slag, and it is necessary to be electrified to make the large block slag into fine sand-like, so after the addition of slag, power feeding is carried out, and small power feeding such as 11, 10, 9, 8 and the like can be selected in the early stage to reduce the burning loss of aluminum; and the aluminum wire can be fed after 8 power feeding.

[0059] The inventor finds that when the preferred target value of the aluminum addition is 0.070%, the white slag can be ensured at sampling time, and the aluminum in the slag can be 24%-31%, reaching a completely deoxidized state, and ensuring the accurate value of the formula calculation. If the aluminum addition is low, the steel slag deoxidation will be poor, and part of the aluminum continues to react with oxygen, resulting in excessive aluminum consumption, and the calculated aluminum in the later stage will be higher than the actual value; if the aluminum addition is high, there will be a certain waste or a phenomenon of not being able to reduce, and the bottom blowing of each ladle is different, and the acid-soluble aluminum in the steel of some ladles with small bottom blowing cannot be reduced in the subsequent normal treatment.

[0060] The inventor also finds that although most heats can meet the requirement of acid-soluble aluminum greater than 0.02% after tapping, aluminum is an easily oxidized element, in order to ensure that the molten steel has more than 0.02% acid-soluble aluminum when it reaches the refining stage, and to calculate and control the acid-soluble aluminum in the refining process, the aluminum wire will be added to 0.05% at the argon station after tapping. If the control range of the acid-soluble aluminum after tapping is low, the consumption of aluminum in the aluminum slag before sampling in the refining process will increase, which is equivalent to reducing the amount of aluminum slag, affecting the total slag amount in the formula and affecting the concentration of acid-soluble aluminum loss.

[0061] Further, the step of sending power to the slag further includes: after feeding the aluminum wire, selecting a gear to increase the temperature according to the temperature of the molten steel, that is, selecting at least one gear from 11 gears, 10 gears, 9 gears, 8 gears, 7 gears, 6 gears, 5 gears, 4 gears, 3 gears, and 2 gears to increase the temperature until the temperature reaches 1565-1570°C, sampling, and measuring the temperature.

[0062] The temperature increasing rate under different gears is as follows:

[0063]

[0064] It should be noted that the addition of 100 kg of slag (lime, fluorite, synthetic slag, aluminum slag, and bauxite) can reduce the molten steel by 2.2°C, the sampling time is generally within 15 minutes or less after the molten steel enters the station, and the amount of slag added is generally fixed for the same steel type, for example: 500 kg of synthetic slag, 120 kg of fluorite is added, and then 360 kg of lime and 120 kg of aluminum slag are added together, the total weight is 500+120+360+120=1100 kg, and the slag material reduces the temperature by 1100 / 100x2.2=24.2°C; the addition of slag takes 2 minutes, and the molten steel naturally cools by 4°C under the stirring of 100 cubic meters / hour of argon gas. In the early stage of slagging, the fixed power is sent for 3 minutes at 8 gears, which is equivalent to the temperature after the slag is melted being the temperature at the station+9-4-24.2=the temperature at the station-19.2°C, and the time being 5 minutes after entering the station, so the remaining 10 minutes can be selected from any one of the four gear combinations in the following table:

[0065]

[0066] Therefore, the step of sending the slag can not use a gear, but can flexibly use multiple gears, and can flexibly switch different gears, for example: use 2 gears for 5 minutes, and then use 8 gears for 5 minutes, as long as the total sending time is greater than 500 seconds, and the temperature is 1565-1570℃.

[0067] It should be noted that when the acid-soluble aluminum of the argon station sample is greater than 0.070%, the 8-gear sending time reaches 180 seconds, and the 4-gear can be directly replaced without feeding the aluminum wire. If the acid-soluble aluminum of the argon station sample is less than 0.070%, the 0.070% is added when the gear is changed.

[0068] Further, the step of sending the slag further comprises: after sampling, the temperature measured during sampling can be used to calculate the rhythm of continuous heating, and the time of heating after sampling is controlled to be within 300 seconds, and the argon flow is kept at 40-60 cubic meters / hour.

[0069] After the heating is completed, if the composition of the sample has not been analyzed, the argon flow can be reduced to 10 cubic meters / hour to avoid excessive burning loss of aluminum in the molten steel under the stirring of large argon, which affects the accuracy of the formula calculation. Generally, the acid-soluble aluminum loss is 0.002% when the test result is obtained in about 3 minutes, and the acid-soluble aluminum loss is 0.003% when the test result is obtained in 5 minutes. The temperature is controlled to be 1565-1570℃ for sampling, mainly to stabilize the sending time and keep it in a small fluctuation range, for example, 190-210 seconds or 290-310 seconds, so as to fix the acid-soluble aluminum loss in this period of time. If the sending time and argon control are different each time, it will affect the accuracy of the formula calculation. At the same time, the sampling time needs to be controlled to be approximately at the end of the sending time, to reduce the idle time after the sending is completed.

[0070] The step of sending the slag further comprises: according to the composition of the sample, the acid-soluble aluminum content is added to 0.073-0.075%, that is, after the composition of the sample is obtained, the composition is added to the internal control range, the acid-soluble aluminum is added to 0.073-0.075%, which includes the aluminum loss during the sending process, that is, the amount of aluminum not removed by ablation, and the standard of the aluminum loss is: during the heating process after the sample is obtained, the acid-soluble aluminum loss is 0.001% per 100 seconds; at the same time, the argon stirring is controlled, and the argon flow is controlled to be 95-105 cubic meters / hour, and the time can be 180-300 seconds, and preferably 180-210 seconds; then, the second sample is taken and the temperature is measured.

[0071] The stirring for 180 seconds or more can effectively remove the aluminum oxide inclusions in the molten steel, preferably 180-210 seconds, the stirring time is controlled to be shorter, the argon consumption can be reduced, the cost can be reduced, the temperature drop of the molten steel is smaller, the cost of the molten steel temperature rise is lower, and the acid-soluble aluminum loss in the steel is smaller.

[0072] It should be noted that the method of the present application is preferably used for a class A ladle or a class B ladle, which is easier to calculate and control the temperature.

[0073] The inventors introduce the stirring temperature drop into the concentration of the acid-soluble aluminum loss in the calculation method, mainly considering the influence of the ladle temperature drop on the aluminum loss, under the same type of ladle, the argon size is related to the aluminum loss, the larger the argon, the larger the aluminum loss; on the other hand, the more the aluminum loss, the more heat released, and the smaller the temperature drop of the molten steel. Therefore, on the basis of controlling the argon at a fixed flow and a fixed stirring time, the smaller the temperature drop of the molten steel, the more the aluminum loss.

[0074] The A\B type ladle has a very small temperature drop, and the process temperature drop is stable, which will not affect the accurate value of the formula, but if it is a C-H type ladle, the temperature drop range of the poor ladle is large, which will affect the accurate value of the formula when used for calculation. According to the formula provided by the present application, for every 1 degree Celsius deviation of the temperature drop, the accurate value of the acid-soluble aluminum calculation will be affected by 0.0001%, and the temperature drop rules of different types of ladles are as follows:

[0075]

[0076]

[0077] According to the concentration of the stirring temperature drop affecting the acid-soluble aluminum loss = [(the temperature of the first sample taken during the power-on slagging process + the temperature increase after the first sample is taken and continues to power on + the temperature of the second sample taken) / (the argon stirring time before the second sample is taken / 60)] x 0.0003%, and the above table, if a class A ladle is used, the parameters of example 1 are substituted: [(1570 + 20 - 1578) / (180 / 60)] x 0.0003% = 0.0012%.

[0078] According to the average temperature drop of the A type ladle in the above table, which is 0.8-0.9℃ per minute, it means that after 3 minutes, the temperature drop is 3x0.8-3x0.9=2.4-2.7℃, and the deviation is only 0.3℃; that is, when the second sample is taken, the measured temperature is 1578℃±0.3, and the influence on the result is 0.0012%±0.00003%, and the calculation method is as follows:

[0079] (1570 + 20 - 1578 - 0.3) / (180 / 60) x 0.0003% = 0.00012% - 0.00003%;

[0080] (1570+20-1578+0.3) / (180 / 60) x 0.0003% = 0.00012% + 0.00003%.

[0081] But if using E type ladle, 3 x 1.3 - 3 x 1.8 = 3.9 - 5.4℃, deviation 1.6℃, sampling two, measured temperature is 1578℃±1.6, the influence on the result is 0.0012%±0.00016%, the calculation method is as follows:

[0082] (1570+20-1578-1.6) / (180 / 60) x 0.0003% = 0.0012% - 0.00016%;

[0083] (1570+20-1578+1.6) / (180 / 60) x 0.0003% = 0.0012% + 0.00016%.

[0084] From the above two groups of comparison, the temperature deviation 1℃, the influence value on the result is about 0.0001%, that is, the above two groups of deviation data 0.0012%±0.00003% and 0.0012%±0.00016%.

[0085] The features and performances of the present application are further described in detail below in combination with examples.

[0086] Example 1

[0087] The smelting process of the cold heading steel includes:

[0088] 1. Converter tapping: taking 120 tons of tapping amount as an example, aluminum iron is added according to the end point oxygen content during the converter tapping process, 1 kg of aluminum iron can remove 2 ppm of oxygen, aluminum iron and 500 kg of lime are added when tapping to 30-40 tons; wherein, the aluminum iron contains 50% of aluminum, the recovery rate is 70%, 1 kg of aluminum iron is melted into 120 tons of molten steel, the aluminum content of the molten steel is 2.91 ppm, from the molecular formula of Al2O3, aluminum: oxygen = 27 x 2: 16 x 3 = 54: 48 = 1.125, that is, 2.91 ppm of aluminum can react with 2.58 ppm of oxygen.

[0089] 2. Argon station aluminum distribution: after tapping, the molten steel is transferred to the argon station for sampling, aluminum is distributed to 0.05% according to the composition, and then sampled out of the station.

[0090] 3. LF refining: after the molten steel is put into the LF furnace, the temperature is measured to be 1558℃, 500 kg of synthetic slag is added, 120 kg of fluorite is added after the addition of synthetic slag is completed, and then 360 kg of lime and 120 kg of aluminum slag are added together.

[0091] During the slagging process, the argon gas flow rate is 100 cubic meters per hour, and after the slagging process, the argon gas flow rate is adjusted to 50 cubic meters per hour.

[0092] 4. Slagging and argon blowing: 8-grade power feeding for 200 seconds, according to the acid-soluble aluminum content in the outgoing sample of the argon station, feeding the aluminum wire, increasing the acid-soluble aluminum by 0.001% per 5 meters, and making the acid-soluble aluminum reach 0.070%.

[0093] After feeding the aluminum wire, the temperature is increased to 310 seconds at 4-grade, sampling one, and measuring the temperature, which is 1570°C. At this time, the incoming temperature of the molten steel is selected for power feeding, ensuring that the total temperature increasing time is greater than 500 seconds after the 8-grade power feeding. Since the aluminum slag added in the previous process and the aluminum wire fed are uniformly distributed in the steel slag and molten steel, a certain time is required. Under the condition of 500 seconds and an argon gas flow rate of 50 cubic meters per hour, the acid-soluble aluminum element in each sample is accurate. If the time is short, the test value will be higher than the actual value. In addition, the incoming temperature of each molten steel is different, ranging from 1552°C to 1590°C, and the temperature is reduced by about 28°C after slagging. If the incoming temperature is high, for example, 1600°C, even if 11-grade is used throughout the process, the temperature of sampling one is 1584°C, which is much higher than 1570°C. Therefore, after sampling one, 11-grade power feeding is continued.

[0094]

[0095] According to the temperature of sampling one, power feeding is performed for 200 seconds to increase the temperature by 20°C, so that the temperature reaches 1590°C, and the argon gas flow rate is maintained at 50 cubic meters per hour.

[0096] After the composition of sampling one is obtained, the acid-soluble aluminum concentration in the steel is calculated and estimated according to the formula, and the argon gas flow rate is maintained at 100 cubic meters per hour for 180 seconds, and then sampling two is taken to measure the temperature, which is 1578°C.

[0097] The above formula is: acid-soluble aluminum concentration = estimated acid-soluble aluminum concentration in the steel - total slag amount affecting acid-soluble aluminum loss concentration - stirring temperature drop affecting acid-soluble aluminum loss concentration - stirring time affecting acid-soluble aluminum loss concentration, wherein the acid-soluble aluminum concentration of the cold heading steel, i.e., the acid-soluble aluminum concentration of sampling two.

[0098] The estimated concentration of acid-soluble aluminum in the steel = the concentration of acid-soluble aluminum in sample one taken during the electric smelting slag process + the concentration of acid-soluble aluminum increased by feeding the aluminum wire during the electric smelting slag process - the concentration of acid-soluble aluminum lost during the electric smelting slag process. The concentration of acid-soluble aluminum increased by feeding the aluminum wire during the electric smelting slag process is 0.052%; the concentration of acid-soluble aluminum increased by feeding the aluminum wire 120 meters is 0.024%; the concentration of acid-soluble aluminum lost during the electric smelting slag process is 0.002% after sample one is taken and the temperature is raised by 20°C for 200 seconds; and 0.052% + 0.024% - 0.002% = 0.074% is calculated, i.e. the estimated concentration of acid-soluble aluminum in the steel is 0.074%.

[0099] The concentration of acid-soluble aluminum loss affected by the total amount of slag = [(the weight of aluminum slag added in the LF refining + the weight of fluorite added in the LF refining) / (the weight of lime added in the LF refining + the weight of lime added in the converter tapping + the weight of synthetic slag added in the LF refining)] x 0.0021%. The weight of aluminum slag is 120 kg, the weight of fluorite is 120 kg, the total weight of lime is 860, and the weight of synthetic slag is 500 kg; [(120 + 120) / (860 + 500)] x 0.0021% = 0.00037% is calculated, i.e. the concentration of acid-soluble aluminum loss affected by the total amount of slag is 0.00037%.

[0100] The concentration of acid-soluble aluminum loss affected by the stirring temperature drop = [(the temperature of sample one taken during the electric smelting slag process + the increased temperature after the sample one is taken and the temperature is raised by 200 seconds of electric smelting + 20°C) / (the stirring time before sample two is taken / 60)] x 0.0003%; wherein the temperature of sample one taken during the electric smelting slag process is 1570°C, the temperature is raised by 20°C for 200 seconds after sample one is taken, and the temperature of sample two is 1578°C; the stirring time is 180 seconds; [(1570 + 20 - 1578) / (180 / 60)] x 0.0003% = 0.0012% is calculated, i.e. the concentration of acid-soluble aluminum loss affected by the stirring temperature drop is 0.0012%.

[0101] The concentration of acid-soluble aluminum loss affected by the stirring time = (the stirring time before sample two is taken / 10) x 0.001%; wherein the stirring time is 180 seconds, and 180 / 10 x 0.001% = 0.018% is calculated, i.e. the concentration of acid-soluble aluminum loss affected by the stirring time is 0.018%.

[0102] The calculated concentration of acid-soluble aluminum = 0.074% - 0.00037% - 0.0012% - 0.018% = 0.054%.

[0103] The directly detected data of acid-soluble aluminum after sample two is taken is 0.054%.

[0104] Comparative Example 1

[0105] Comparative Example 1 and Example 1 were the same in other operations, except that the sequence of adding aluminum dross after the molten steel was transferred to the LF furnace was changed, i.e., the aluminum dross was added first, and then the synthetic slag, fluorite and lime were sequentially added.

[0106] The addition of aluminum dross first caused the whole slag body to foam and mix into the slag body, and the subsequently added slag materials (synthetic slag, fluorite and lime) could not mix with the previously added aluminum dross. The specific reason is that after the addition of aluminum dross, the slag body foams and expands rapidly, thereby quickly mixing into the slag body, but other slag materials cannot do so and can only mix with the slag near the argon port at the position of addition; on the other hand, the foaming formed by the previously added aluminum dross, under the action of strong argon stirring, causes the gas to be quickly discharged, and when the subsequent slag materials are continuously added, due to the large amount of gas discharged and the reduction of gas, the slag is not foamed, the function of the slag to isolate the exposed part of the molten steel becomes worse and worse, resulting in the exposure of the molten steel and the burning loss of acid-soluble aluminum. Therefore, the deoxidation in the slag is not complete, and the aluminum loss is increased in the 180 seconds of stirring before the second sample, resulting in that the actual acid-soluble aluminum is lower than the calculated value, and the calculated value is 0.054%, while the actual detected value is 0.046%-0.048%. It can be seen that the sequence of adding slag materials will affect the calculation result.

[0107] Comparative Example 2

[0108] Comparative Example 2 and Example 1 were the same in other operations, except that the treatment of the molten steel at the argon station was changed, i.e., the aluminum was not added to 0.050%, but only to 0.020%.

[0109] Due to the small amount of aluminum added at the argon station, when the acid-soluble aluminum in the molten steel is lower than 0.020%, the molten steel cannot be completely deoxidized, and then in the early stage of adding slag materials in the LF furnace, the calcium oxide in the lime will be oxidized to reduce the calcium oxide content in the slag, so that the slag becomes thinner than that of Comparative Example 1, and the slag becomes thinner, and the acid-soluble aluminum loss in the molten steel will be more; this will affect the concentration of the acid-soluble aluminum loss in the formula total slag amount, wherein the oxidation of lime is equivalent to the less amount of lime added, which is equivalent to the smaller denominator in the formula, so that the coefficient value will become larger; on the other hand, it will affect the concentration of the acid-soluble aluminum loss by affecting the stirring temperature drop, because the slag becomes thinner, the temperature drop will be larger, and the numerator in the formula will become smaller, so that the result will become smaller; on the other hand, it will affect the concentration of the acid-soluble aluminum loss by affecting the stirring time, because the original loss of 0.001% per 10 seconds, due to the thinner slag, the oxidation will be faster, and now the loss is 0.0012%-0.0014% per 10 seconds, which affects the result of the formula to become larger.

[0110] Comparative Example 3

[0111] Comparative Example 3 and Example 1 were the same in other operations, except that the treatment of the molten steel at the argon station was changed, i.e., the aluminum was added to 0.080%.

[0112] The aluminum content in the argon station can be reduced to 0.080%, the aluminum content before the LF furnace can be reduced, and the aluminum content after the sample one can be reduced, the acid-soluble aluminum content can be reduced to 0.070% when the power is supplied for 200 seconds, the aluminum content can be reduced to 0.073%-0.075% when the sample one is taken, and the calculation result of the formula is not affected.

[0113] However, this will greatly increase the alumina inclusions, because the alumina inclusions are the product of the reaction of molten steel with oxygen, and a large amount of inclusions will be added before the slag is formed, which will increase the difficulty of removing the inclusions in the molten steel, and the inclusions will be in the slag after the aluminum is added in the LF furnace, thereby greatly reducing the inclusions in the molten steel.

[0114] Comparative Example 4

[0115] Comparative Example 4 has the same operation as Example 1, except that the slag material is not added first when entering the LF furnace, but the power is supplied directly, and the argon gas of 50 cubic meters / hour is also selected, and then the slag material is added while the power is supplied.

[0116] Such operation will cause a part of the aluminum in the slag to be burned by the high temperature generated by the electrode when the power is supplied, and the aluminum in the slag will be reduced, which will affect the total slag amount and the concentration of the acid-soluble aluminum burn loss, which is equivalent to a decrease in the number of molecules, and the calculation result of the formula will decrease. Because the aluminum in the slag is less, the acid-soluble aluminum in the molten steel will transfer to the slag during the 180-second stirring of the sample two, until the alumina in the slag is saturated, which will increase the consumption of the acid-soluble aluminum in the molten steel during this period. Originally, the burn loss of the acid-soluble aluminum in the molten steel was 0.001% per 10 seconds, and now it is 0.0011%-0.0014% per 10 seconds.

[0117] Comparative Example 5

[0118] Comparative Example 5 has the same operation as Example 1, except that the temperature control when the sample one is taken is changed, the temperature when entering the station is 1558°C, the temperature is reduced by 28°C by adding slag material, and the power is supplied at 11 gears throughout the process, and the temperature of the molten steel is (1558-28)+(500 / 60) x 1.5=1542°C after 500 seconds.

[0119] Because the temperature when the sample one is taken is low, the power supply time after the sample one is taken is increased, and the calculation accuracy of the acid-soluble burn loss will be affected during this process, because under the same conditions of the same argon gas, the same power supply gear, etc., the acid-soluble aluminum burn loss in the steel is a relatively stable range, but the range will be larger, for example, the aluminum burn loss is stable at 0.002% when the power is supplied for 200 seconds, but the aluminum burn loss range is 0.006%-0.009% when the power is supplied for 600 seconds. Ultimately, the actual value of the estimated acid-soluble aluminum concentration in the steel will be lower than the estimated value.

[0120] Comparative Example 6

[0121] Comparative Example 6 is the same as Example 1 except that the sample 1 pre-arc time (total heating time) is 400 seconds.

[0122] If the sample 1 pre-arc time is too short, it is difficult to avoid the phenomenon of unsaturated deoxidization in the slag, i.e. aluminum is still deoxidizing in the steel or slag, and the sample is taken before the deoxidization is complete, resulting in a high acid-soluble aluminum in the sample, which leads to a high result calculated by the formula. Because part of the aluminum continues to participate in the deoxidization reaction, 50 cubic meters / hour of argon is required for stirring, and the arc is applied for more than 500 seconds. If the temperature is high, a low gear arc can be selected to ensure the arc time.

[0123] It should be noted that if 70 cubic meters / hour or more of argon is used, the total heating time can be less than 500 seconds, although it can ensure the accuracy of the acid-soluble aluminum at the time of sample 1, the acid-soluble aluminum loss during the arc process is greater, and the accuracy of the final calculation result cannot be guaranteed.

[0124] Comparative Example 7

[0125] Comparative Example 7 is the same as Example 1 except that the temperature control at the time of sample 1 is changed, the temperature is 1600°C, and then the argon is reduced to 10 cubic meters / hour, and then the sample 1 result is waited for, which can reduce the loss of acid-soluble aluminum in the molten steel and obtain an accurate and stable value.

[0126] However, after the argon flow is reduced, the stirring intensity is reduced to 1 / 5 of Example 1, the fluidity of the slag will be greatly reduced or there will be no fluidity, so the aluminum oxide formed in the slag is less, and the reduction of the fluidity of the slag will affect the ability to absorb inclusions, and the serious consequence is that the molten steel cannot be drawn out during the continuous casting and pouring process, the reason is that the aluminum oxide inclusions in the molten steel are high, which sticks to the continuous casting nozzle, making the nozzle smaller, the flow rate of the molten steel is reduced, and the normal speed is not reached, i.e. although the accuracy of the calculation result is guaranteed, high quality steel cannot be produced.

[0127] Comparative Example 8

[0128] Comparative Example 8 is the same as Example 1 except that the temperature control at the time of sample 2 is changed (which can also be considered as a different time system), the temperature at the time of sample 2 is 1550°C.

[0129] After stirring for 180 seconds, the argon gas is turned off and the sample is taken. The acid-soluble aluminum of the second sample calculated according to the formula is accurate, but if the sample is not taken after stirring and the argon blowing is continued until the temperature drops to 1550°C or another temperature, the result will be inaccurate and the result of the sample will be lower than the result calculated according to the formula. In addition, it also affects the control of the acid-soluble aluminum of the refining outlet. Compared with Example 1, the temperature rising time after the second sample is taken will increase. In Example 1, the temperature is 1578°C when the second sample is taken, the temperature is raised to 1585°C by using 4 gears for 70 seconds, and the calcium line is fed and soft blown. The process acid-soluble aluminum loss is 0.001%. However, in Comparative Example 7, the temperature is raised to 1585°C by using 4 gears for 350 seconds, and the process acid-soluble aluminum loss is 0.006%. It is certain that the result will be lower than that of Example 1. If the sampling time is not specified after stirring, it is not conducive to the accurate control of the acid-soluble aluminum of the refining outlet.

[0130] Comparative Example 9

[0131] Comparative Example 9 is the same as Example 1 in other operations, except that the temperature control after the first sample is taken is changed to 1610°C.

[0132] Compared with Example 1, the temperature control after the first sample is taken is changed to 1610°C. In Comparative Example 9, the temperature is raised to 1610°C after the first sample is taken. After stirring, the temperature is 1598°C or higher. In order to reduce the temperature to 1585°C, the argon gas needs to be stirred at a high flow rate or the temperature needs to be naturally reduced to 1585°C for a longer time. The change of the argon blowing flow rate or the length of the waiting time will affect the control of the acid-soluble aluminum of the refining outlet. The result will be lower than that of Example 1.

[0133] Comparative Example 10

[0134] Comparative Example 10 is the same as Example 1 in other operations, except that the acid-soluble aluminum is changed to 0.065% after the composition of the first sample is taken.

[0135] In addition to affecting the acid-soluble aluminum of the refining outlet, which is lower than that of Example 1, because the initial aluminum is lower, it also affects the concentration of the acid-soluble aluminum loss affected by the stirring temperature drop. The actual value will be lower than the calculated value.

[0136] In addition, even if not considering the formula calculation, assuming the same conditions, the acid-soluble aluminum during stirring is 0.020%, the Example 1 is 0.074%, and the acid-soluble aluminum after stirring is 0.074%-0.020%=0.054%, and the Comparative Example 10 is 0.065%-0.020%=0.045%.

[0137] The acid-soluble aluminum is less by 0.003%-0.004% during subsequent calcium feeding, and less by 0.002%-0.004% during soft blowing. During continuous casting, the acid-soluble aluminum is also burned by 10%-15%. That is, at the time of sampling 2, the acid-soluble aluminum is only 0.038%, which is very close to the lower limit of the finished product composition. (0.045%-0.004%-0.004%)-(0.045%-0.004%-0.004%)x15%=0.031%. The internal control range of the acid-soluble aluminum of the finished product is 0.030%-0.045%. If the acid-soluble aluminum is less than 0.065% for the composition, the probability of aluminum composition at sampling 2 is very high.

[0138] Comparative Example 11

[0139] Comparative Example 11 has the same operation as Example 1, except that after the composition of sampling 1 is changed, the aluminum is composed of 0.085%. Under the same conditions, the acid-soluble aluminum in the molten steel is high, and the burn loss is relatively large. The actual value will be lower than the result calculated by the formula.

[0140] The inventor found from Comparative Example 10 and Comparative Example 11 that if the aluminum composition after sampling 1 is low, the acid-soluble aluminum at sampling 2 will be insufficient, and the aluminum needs to be continuously composed, which will delay the refining time. If it is high, it also needs to be opened for large argon stirring, and the acid-soluble aluminum is burned twice, which wastes time, and also wastes argon and temperature, and increases the inclusion of aluminum trioxide.

[0141] Furthermore, after sample one is taken out, the acid-soluble aluminum is 0.073%-0.075%, the argon gas flow is 100 cubic meters / hour, the stirring time is 180 seconds, the burn loss of the acid-soluble aluminum is 0.016%-0.021%, which is affected by the amount of slag, the deoxidation degree and the initial aluminum. If the argon gas flow is changed to 70 cubic meters / hour, the stirring time will affect the concentration of the acid-soluble aluminum burn loss, the original burn loss is 0.001% per 10 seconds, now the burn loss is only 0.0006%-0.0008%. On the other hand, after sample two is taken out, the acid-soluble aluminum will be less by 0.003%-0.004% when feeding calcium wire, and the acid-soluble aluminum will be less by 0.002%-0.004% during the soft blowing process. During the continuous casting process, the acid-soluble aluminum will be burned by 10%-15%, and the finished product is just 0.035%-0.045%, so the aluminum before sample two is in the range of 0.073%-0.075%, which can make the acid-soluble aluminum of sample two controlled in the range of 0.050%-0.055%, so as to meet the requirements.

[0142] According to the comparison between the acid-soluble aluminum data calculated in the examples and various comparative examples and the actually detected acid-soluble aluminum data, it can be known that the calculation method of the present application can predict the acid-soluble aluminum content of the cold heading steel in a smaller error range.

[0143] In summary, the calculation method of the acid-soluble aluminum of the cold heading steel of the present application can calculate the concentration of the acid-soluble aluminum in advance, which is beneficial to avoid the problems of aluminum supplement or aluminum content exceeding the standard in the later process, and is further beneficial to prepare the cold heading steel with the quality meeting the requirements.

[0144] The above only describes the preferred embodiments of the present application and is not used to limit the present application. For those skilled in the art, the present application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application shall be included in the protection scope of the present application.

Claims

1. A method for calculating the acid soluble aluminum of cold heading steel, characterized by, Comprising: The concentration of acid-soluble aluminum after the electrically powered slag and argon blowing stirring is calculated according to the following formula, The concentration of acid-soluble aluminum = the estimated concentration of acid-soluble aluminum in the steel - the concentration of acid-soluble aluminum burned by the total slag amount - the concentration of acid-soluble aluminum burned by the stirring temperature drop - the concentration of acid-soluble aluminum burned by the stirring time; wherein, The estimated concentration of acid-soluble aluminum in the steel = the concentration of aluminum in sample one taken during the electrically powered slag process + the concentration of acid-soluble aluminum increased by the aluminum wire fed during the electrically powered slag process - the concentration of acid-soluble aluminum lost during the electrically powered slag process; The concentration of acid-soluble aluminum burned by the total slag amount = [(the weight of aluminum slag added in the LF refining + the weight of fluorite added in the LF refining) / (the weight of lime added in the LF refining + the weight of lime added in the converter tapping + the weight of synthetic slag added in the LF refining)] x 0.0021%; The concentration of acid-soluble aluminum burned by the stirring temperature drop = [(the temperature of sample one taken during the electrically powered slag process + the temperature increased by the continued electrically powered temperature rise after sample one is taken - the temperature of sample two) / (the argon blowing stirring time before sample two is taken / 60)] x 0.0003%; The concentration of acid-soluble aluminum burned by the stirring time = (the argon blowing stirring time before sample two is taken / 10) x 0.001%.

2. The method for calculating the acid-soluble aluminum content of cold-heading steel according to claim 1, characterized in that, The calculation method of acid-soluble aluminum for the cold heading steel is used for smelting processes of the cold heading steel including converter tapping, argon station aluminum distribution, LF refining, electrically powered slag and argon blowing; wherein, The step of the converter tapping includes adding aluminum iron according to the end point oxygen content.

3. The method for calculating the acid-soluble aluminum content of cold-heading steel according to claim 2, characterized in that, The amount of the aluminum iron is calculated according to the standard of 2ppm of deoxidation per 0.8-1.2kg of aluminum iron, wherein the aluminum content of the aluminum iron is 45%-55%, and the yield is 65%-75%.

4. The method for calculating the acid-soluble aluminum content of cold-heading steel according to claim 2 or 3, characterized in that, The process of the converter tapping further includes adding lime.

5. The method for calculating the acid-soluble aluminum content of cold-heading steel according to claim 2, characterized in that, The step of the argon station aluminum distribution includes distributing the aluminum content to 0.04%-0.06% by mass percentage.

6. The method for calculating the acid-soluble aluminum content of cold-heading steel according to claim 2, characterized in that, The step of the LF refining includes adding synthetic slag, fluorite, lime and aluminum slag, and argon blowing stirring, wherein during the process of adding the slag, the standard of argon blowing is 95-105 cubic meters / hour, and after the slag is added, the standard of argon blowing is adjusted to 40-60 cubic meters / hour.

7. The method for calculating the acid-soluble aluminum content of cold-heading steel according to claim 2, characterized in that, The step of the electrically powered slag includes using 8 gears for the electrically powered slag when the temperature of the molten steel at the station is less than 1561℃; Using 9 gears for the electrically powered slag when the temperature of the molten steel at the station is 1561-1570℃; Using 10 gears for the electrically powered slag when the temperature of the molten steel at the station is 1571-1580℃; Using 11 gears for the electrically powered slag when the temperature of the molten steel at the station is greater than 1580℃; Feeding aluminum wire according to the acid-soluble aluminum content of the argon station sample, wherein the aluminum content of every 5 meters of aluminum wire is increased by 0.001%.

8. The method for calculating the acid-soluble aluminum content of cold-heading steel according to claim 7, characterized in that, The step of the electrically powered slag further includes selecting at least one gear from 11 gears, 10 gears, 9 gears, 8 gears, 7 gears, 6 gears, 5 gears, 4 gears, 3 gears, 2 gears for temperature rise after the aluminum wire is fed, until the temperature reaches 1565℃-1570℃, sample one is taken, and the temperature is measured.

9. The method for calculating the acid-soluble aluminum content of cold-heading steel according to claim 8, characterized in that, The step of the electrically powered slag further includes, after sample one is taken, continuing to raise the temperature and controlling the temperature rising time within 300 seconds, and the flow of argon blowing during the temperature rising process is maintained at 40-60 cubic meters / hour.

10. The method for calculating the acid-soluble aluminum content of cold-heading steel according to claim 9, characterized in that, The step of sending the slag also includes: according to the component of the sample, the content of acid-soluble aluminum is matched to 0.073-0.075%, while argon blowing stirring is carried out, and the argon blowing flow is controlled to be 95-105 cubic meters / hour, then the sample two is taken, and the temperature is measured.

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