CN115747406A - Ultra-low phosphorus steel converter smelting method - Google Patents
Ultra-low phosphorus steel converter smelting method Download PDFInfo
- Publication number
- CN115747406A CN115747406A CN202211543867.2A CN202211543867A CN115747406A CN 115747406 A CN115747406 A CN 115747406A CN 202211543867 A CN202211543867 A CN 202211543867A CN 115747406 A CN115747406 A CN 115747406A
- Authority
- CN
- China
- Prior art keywords
- blowing
- steel
- oxygen
- ultra
- converter
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 96
- 239000010959 steel Substances 0.000 title claims abstract description 96
- 238000000034 method Methods 0.000 title claims abstract description 72
- 229910052698 phosphorus Inorganic materials 0.000 title claims abstract description 49
- 239000011574 phosphorus Substances 0.000 title claims abstract description 49
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 title claims abstract description 47
- 238000003723 Smelting Methods 0.000 title claims abstract description 29
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 125
- 239000001301 oxygen Substances 0.000 claims abstract description 125
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 125
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims abstract description 102
- 238000007664 blowing Methods 0.000 claims abstract description 90
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 78
- 239000002893 slag Substances 0.000 claims abstract description 57
- 229910052786 argon Inorganic materials 0.000 claims abstract description 51
- 229910052742 iron Inorganic materials 0.000 claims abstract description 39
- 235000008733 Citrus aurantifolia Nutrition 0.000 claims abstract description 17
- 235000011941 Tilia x europaea Nutrition 0.000 claims abstract description 17
- 239000004571 lime Substances 0.000 claims abstract description 17
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 14
- 229910052799 carbon Inorganic materials 0.000 claims description 12
- 230000000694 effects Effects 0.000 abstract description 10
- 238000003756 stirring Methods 0.000 abstract description 8
- 238000010079 rubber tapping Methods 0.000 description 9
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 6
- 230000000903 blocking effect Effects 0.000 description 5
- 239000000463 material Substances 0.000 description 4
- 230000009286 beneficial effect Effects 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 229910052757 nitrogen Inorganic materials 0.000 description 3
- 229910000519 Ferrosilicon Inorganic materials 0.000 description 2
- ODINCKMPIJJUCX-UHFFFAOYSA-N calcium oxide Inorganic materials [Ca]=O ODINCKMPIJJUCX-UHFFFAOYSA-N 0.000 description 2
- 239000000292 calcium oxide Substances 0.000 description 2
- 239000003795 chemical substances by application Substances 0.000 description 2
- 230000007547 defect Effects 0.000 description 2
- 230000001590 oxidative effect Effects 0.000 description 2
- 229910000851 Alloy steel Inorganic materials 0.000 description 1
- 229910004261 CaF 2 Inorganic materials 0.000 description 1
- BRPQOXSCLDDYGP-UHFFFAOYSA-N calcium oxide Chemical compound [O-2].[Ca+2] BRPQOXSCLDDYGP-UHFFFAOYSA-N 0.000 description 1
- 239000003153 chemical reaction reagent Substances 0.000 description 1
- 230000003749 cleanliness Effects 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000009191 jumping Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000007800 oxidant agent Substances 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 239000000523 sample Substances 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000009628 steelmaking Methods 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Carbon Steel Or Casting Steel Manufacturing (AREA)
Abstract
The invention discloses a smelting method of an ultra-low phosphorus steel converter, which comprises the following steps: mixing molten iron and scrap steel to obtain molten steel, and sequentially carrying out combined blowing, primary slagging, deslagging, continuous blowing, secondary slagging, post-blowing and end point control on the molten steel to obtain the molten steel. The invention determines the slag pouring time through the oxygen blowing amount, avoids the fluctuation of manual pure experience control, controls the alkalinity and the oxidability of early-stage slag and the temperature of semisteel in the furnace by adjusting the adding amount of lime and iron ore, ensures the early-stage dephosphorization effect, lightens the subsequent dephosphorization pressure, stirs slag and molten steel by combining bottom blowing argon after stopping oxygen supply, increases the reaction interface of steel slag to further dephosphorize, and finally the phosphorus content in the molten steel is below 0.004 percent.
Description
Technical Field
The invention belongs to the technical field of steel smelting, and particularly relates to a method for smelting ultra-low phosphorus steel by a converter.
Background
At present, steel enterprises produce steel grades such as case hardening high-quality alloy steel, tin-plated steel, deep drawing steel, low-temperature steel, marine steel and the like, and the phosphorus element mass content of the steel grades is required to be below 0.004 percent. As the comprehensive value of the phosphorus content in the molten iron supplied to the converter by the blast furnace is more than 0.16 percent, the phosphorus content at the end point of the molten steel in the furnace is difficult to be ensured to be less than 0.004 percent by empirical operation in the steelmaking process of the converter.
At present, the main methods for producing the converter low-phosphorus steel at home and abroad comprise:
1. pre-dephosphorizing molten iron and dephosphorizing in a converter: the molten iron adopts an oxidant containing FeO, a fixing agent containing CaO and BaO and a fixing agent containing CaF 2 、CaCO 3 The accelerant and the lime base material are used for molten iron dephosphorization, the dephosphorization rate of the molten iron reaches more than 80 percent, the defects are that the temperature drop in the treatment process is large, the splashing is large when the temperature drop is compensated by oxygen blowing, and meanwhile, the ladle or the torpedo tank is small in size, slow in reaction and low in efficiency. While requiring pre-treatment equipment.
2. Converter dephosphorization and external dephosphorization: the converter adopts double-slag smelting, the deoxidation is not carried out during tapping, and the synthetic slag is added to carry out the dephosphorization outside the furnace through ladle argon blowing. The disadvantages are that slag removing equipment is added, slag removing is not clean, and efficiency is low.
3. Dephosphorization is carried out by a double-converter: dephosphorization is carried out firstly by adopting one converter, and decarburization is carried out by adopting one converter, so that the defects of low efficiency and large temperature loss of molten iron entering and exiting the converter twice are overcome.
4. The converter double-slag method comprises the following steps: and (3) deslagging when the converter supplies oxygen to 35-40% of the total oxygen, and dephosphorizing by stirring by bottom blowing nitrogen after the later continuous blowing is finished, or dephosphorizing by adding carbon powder or ferrosilicon reconstructed slag. The adoption of bottom-blown nitrogen stirring can cause nitrogen increase of molten steel and influence the cleanliness of the molten steel. After the continuous blowing is finished, carbon powder and ferrosilicon are added again for slagging, so that the cost is increased, and the efficiency is reduced.
In the above technologies, the tapping phosphorus can be reluctantly controlled within 0.005% by adopting a double-converter dephosphorization method, a double-slag method and the like, and the tapping phosphorus can be stably controlled within 0.015% by adopting a single-slag method, but the difficulty of controlling the tapping phosphorus below 0.004% is large.
Therefore, the invention provides a method for smelting ultra-low phosphorus steel in a converter. To solve the problems set forth in the background art described above.
Disclosure of Invention
The invention aims to provide a method for smelting ultra-low phosphorus steel in a converter, which can effectively control the end-point phosphorus element mass content of molten steel to be below 0.004% in the converter smelting process.
Specifically, the invention provides a method for smelting ultra-low phosphorus steel in a converter, which comprises the following steps: mixing molten iron and scrap steel to obtain molten steel, and sequentially carrying out combined blowing, primary slagging, deslagging, continuous blowing, secondary slagging, post-blowing and end point control on the molten steel to obtain molten steel;
the mass content of the phosphorus element in the molten steel is below 0.004%;
the oxygen flow in the secondary blowing process is 45000m 3 /h-50000m 3 /h；
The oxygen pressure in the secondary blowing process is 0.90MPa-1.0MPa;
the intensity of argon supplied in the combined blowing process is 0.02Nm 3 /(min·t)-0.08Nm 3 /(min·t)；
The oxygen flow rate in the continuous blowing process is 45000m 3 /h-50000m 3 /h；
The oxygen pressure in the continuous blowing process is 0.90MPa-1.0MPa;
the intensity of argon supplied in the continuous blowing process is 0.02Nm 3 /(min·t)-0.08Nm 3 /(min·t)。
According to one of the technical schemes of the method, the method at least has the following beneficial effects:
the converter dephosphorization needs high oxidizability, the invention can improve the slagging speed and reduce the carbon content by reasonably designing the flow and the pressure of oxygen, and can ensure the effective dephosphorization of molten steel under the condition of adding auxiliary materials as little as possible, the oxygen jet can generate shock waves when the oxygen supply pressure is too large or too small, the energy loss of the jet is increased, the early dephosphorization effect is influenced, the splashing can be caused when the oxygen supply flow is too large, and the blowing time of the converter can be prolonged when the oxygen supply flow is too small, so the efficiency is reduced. Effectively control the argon flow and the pressure, realize the reasonable stirring effect of the molten steel, improve the reaction contact interface and improve the smelting efficiency.
In some embodiments of the invention, the argon supply intensity during the end-point control is 0.06Nm 3 /(min·t)-0.08Nm 3 /(min·t)；
And the time for supplying argon in the end point control process is 2min-3min.
The characteristics of high oxidizability, high alkalinity and large slag amount are controlled by using a terminal point, and after oxygen supply is stopped, slag and molten steel are stirred by combining bottom blowing argon, so that a steel slag reaction interface is increased for further dephosphorization.
In some embodiments of the invention, the post-blown molten steel has a carbon content of 0.03 to 0.06 percent and a temperature of 1560 to 1580 ℃.
According to the thermodynamic condition of dephosphorization, the higher oxidizability and the lower end temperature of the end point are controlled in the later period, and under the condition, the steel slag reaction interface is promoted by bottom blowing argon stirring from the aspect of dynamics, so that deep dephosphorization can be comprehensively realized.
In some embodiments of the invention, the argon supply intensity during said post-blowing is 0.02Nm 3 /(min·t)-0.08Nm 3 /(min·t)；
The oxygen flow in the post-blowing process is 45000m 3 /h-50000m 3 /h；
The oxygen pressure in the post-blowing process is 0.90MPa-1.0MPa.
Proper oxygen pressure and flow are controlled, the influence of dry returning on the dephosphorization effect is prevented, and the dephosphorization is facilitated by combining bottom blowing stirring.
In some embodiments of the invention, the first slagging is carried out with iron ore in an amount of from 10kg/t to 15kg/t;
the lime adding amount in the first slag making is 20kg/t-25kg/t.
In some embodiments of the invention, the first slagging temperature is 1350 ℃ to 1400 ℃.
In some embodiments of the invention, the first slagging binary basicity is in the range of 1.6 to 2.0.
The early-stage dephosphorization rate can be ensured by adjusting the adding amount of lime and iron ore, controlling the alkalinity and the oxidability of early-stage slag and the temperature of semisteel in the furnace, and the high-phosphorus slag in the furnace is poured out by increasing the step of pouring the early-stage slag to reduce the follow-up dephosphorization pressure.
In some embodiments of the invention, the second slagging temperature is 1560 ℃ to 1580 ℃.
In some embodiments of the invention, the second slagging temperature is 1562 ℃ to 1575 ℃.
In some embodiments of the invention, the second slagging temperature is 1570 ℃.
In some embodiments of the invention, the secondary slagging binary basicity is in the range of 3.2 to 3.4.
In consideration of thermodynamics, the appropriate end point temperature is controlled, and the relatively high binary alkalinity can be met under certain oxidizing conditions, so that the increase of calcium oxide in the slag is beneficial to dephosphorization, but the increase of the viscosity of the slag can occur due to too high alkalinity, and the dephosphorization effect is reduced.
In some embodiments of the invention, the scrap steel weight fraction is from 10% to 25%.
The waste steel is added into the molten iron to play a cooling role, so that the converter achieves heat balance in the blowing process, the qualified end temperature is reached, the splashing is reduced, and the cost can be reduced.
In some embodiments of the present invention, the content of phosphorus in the molten iron is 0.14% to 0.18%.
In some embodiments of the invention, the second slagging iron ore addition is determined as follows: when the temperature of the semisteel in the furnace is 1570 ℃, 10kg/t of iron ores are added, when the temperature of the semisteel is increased by 10 ℃, the adding amount of the iron ores is increased by 1.6 kg/t, and when the temperature of the semisteel is lower than 10 ℃, the adding amount of the iron ores is reduced by 1.6 kg/t.
In some embodiments of the invention, the total oxygen supply is 9300m 3 -9710m 3 。
In some embodiments of the invention, t is the weight per ton of molten steel.
In some embodiments of the invention, the oxygen lance position during the double blow is 1.7m.
In some embodiments of the invention, the oxygen lance position is adjusted to 1.8m-2.20m after the oxygen lance blows oxygen to 10% -15% of the total oxygen supply.
In some embodiments of the invention, the oxygen lance position during the continuous blowing is between 1.7m and 2.3m.
In some embodiments of the invention, the post-blow process has an oxygen lance position of 1.7m to 2.3m.
In some embodiments of the invention, the deslagging time is when the oxygen lance blows oxygen to the furnace mouth with the oxygen supply amount of 30-50% of the total oxygen supply amount and slag jumping is started, and the earlier stage slag is poured.
In some embodiments of the invention, the converter pour angle is from 55 ° to 65 °.
Compared with the prior art, the technical scheme of the invention has the following beneficial technical effects:
1. the invention provides a method for smelting ultra-low phosphorus steel in a converter, and the phosphorus content of molten steel produced by the smelting method is below 0.004 percent by mass.
2. According to the invention, the slag pouring time is determined by the oxygen blowing amount, the fluctuation of manual pure experience control is avoided, the alkalinity and the oxidability of early-stage slag and the temperature of semisteel in the furnace are controlled by adjusting the adding amount of lime and iron ore, the early-stage dephosphorization effect is ensured, and the subsequent dephosphorization pressure is reduced.
3. By utilizing the characteristics of high oxidizability, high alkalinity and large slag amount at the end point, after oxygen supply is stopped, bottom blowing argon is combined to stir slag and molten steel, and a steel slag reaction interface is increased to further dephosphorize.
Detailed Description
The concept and technical effects of the present invention will be clearly and completely described below in conjunction with the embodiments to fully understand the objects, features and effects of the present invention. It is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments, and those skilled in the art can obtain other embodiments without inventive effort based on the embodiments of the present invention, and all embodiments are within the protection scope of the present invention.
In the description of the present invention, reference to the description of the terms "one embodiment," "some embodiments," "an illustrative embodiment," "an example," "a specific example," or "some examples," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.
The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.
Specific examples of the present invention are described in detail below.
The temperature and the component content of the molten steel are obtained by measuring a TSC probe of the sublance.
Specific examples of the present invention are described in detail below.
Example 1
The smelting method of the ultra-low phosphorus steel converter comprises the following steps:
molten iron with a phosphorus content of 0.151 percent is poured into the converter, the weight of the molten iron is 180t, and simultaneously, 45t of scrap steel is added into the converter and mixed to obtain molten steel. Controlling the total oxygen supply to be 9315m 3 And then the following operations are sequentially carried out on the molten steel:
(1) And (3) secondary blowing: the oxygen lance position is controlled to be 1.7m, and the top-blown oxygen flow is controlled to be 47000m 3 H, controlling the oxygen pressure to be 0.97MPa, and bottom blowing argon in the whole process, wherein the intensity of the argon supply is 0.05Nm 3 /(min·t)。
(2) First slagging: 12.5kg/t iron ore and 20.5kg/t lime are added into the furnace. The temperature in the furnace is 1360 ℃ and the binary alkalinity is 1.7. When the oxygen blowing amount of the oxygen lance reaches 12 percent of the total oxygen supply amount, namely 1118m 3 Then the oxygen gun position was adjusted to 1.9m.
(3) Deslagging: 4192m when the oxygen lance blows oxygen to 45 percent of the total oxygen supply 3 When the furnace mouth begins to jump slag, the oxygen lance is lifted to the upper part of the furnace mouth, the converter is tilted to 60 degrees to pour the early-stage slag, and the temperature of semisteel in the converter is measured to be 1380 ℃.
(4) And (3) continuous blowing: the oxygen lance was positioned at 2.0m and the converter was continued at a flow rate of 47000m 3 The oxygen top blowing at 0.97MPa and the argon bottom blowing in the whole process, wherein the argon supply intensity is still 0.05Nm 3 /(min·t)
(5) And (3) slagging for the second time: adding 25.0kg/t of lime into the furnace, adding 10kg/t of iron ore, wherein the temperature in the furnace is 1570 ℃, and the binary alkalinity is 3.3.
(6) Post-blowing: the oxygen lance was positioned at 1.9m and the converter was continued at a flow rate of 47000m 3 Oxygen top blowing at 0.97MPa and argon bottom blowing in the whole process, wherein the intensity of argon supply is still 0.075Nm 3 /(min·t)。
(7) And (3) end point control: the carbon content is measured to be 0.035%, the temperature of molten steel is 1578 ℃, the slag is not poured when the oxygen supply is stopped, and the intensity of bottom blowing argon is 0.075Nm 3 /(min. T), hold time 2min.
The carbon content and the phosphorus content of the steel after slag tapping before and after the sliding plate is adopted for blocking are respectively measured to be 0.021% and 0.0028%.
Example 2
The smelting method of the ultra-low phosphorus steel converter comprises the following steps:
molten iron having a phosphorus content of 0.162% was poured into the converter at 182t by weight, and 43t of scrap steel was added to the converter and mixed to obtain molten steel. The total oxygen supply amount is controlled to be 9406m 3 And then the following operations are sequentially carried out on the molten steel:
(1) And (3) secondary blowing: the oxygen lance position is controlled to be 1.7m, and the top blowing oxygen flow is controlled to be 48000m 3 The oxygen pressure is controlled to be 0.98MPa, argon is blown from the bottom in the whole process, and the intensity of the supplied argon is 0.045Nm 3 /(min·t)。
(2) First slagging: 14.0kg/t of iron ore and 21.5kg/t of lime are added into the furnace. The temperature in the furnace is 1370 ℃ and the binary alkalinity is 1.9m. 1222m when oxygen blowing amount of oxygen lance reaches 13% of total oxygen supply amount 3 Then the oxygen gun position was adjusted to 1.95m.
(3) Deslagging: 4233m when the oxygen lance blows oxygen to 45 percent of the total oxygen supply 3 When the furnace mouth begins to jump slag, the oxygen lance is lifted to the upper part of the furnace mouth, the converter is tilted to 60 degrees to pour early-stage slag, and the temperature of semisteel in the converter is measured to be 1389 ℃.
(4) And (3) continuous blowing: the oxygen lance was positioned at 2.1m and the converter was continued at a flow rate of 48000m 3 Oxygen top blowing at 0.98MPa and argon bottom blowing in the whole process, wherein the argon supply intensity is still 0.045Nm 3 /(min·t)。
(5) And (3) slagging for the second time: 28kg/t of lime is added into the furnace, 12kg/t of iron ore is added, the temperature in the furnace is 1575 ℃, and the binary alkalinity is 3.25.
(6) Post-blowing: the oxygen lance was positioned at 1.95m and the converter was continued at a flow rate of 48000m 3 Oxygen top blowing at 0.98MPa and argon bottom blowing in the whole process, wherein the argon supply intensity is still 0.078Nm 3 /(min·t)。
(7) And (3) end point control: the carbon content is 0.034%, the molten steel temperature is 1575 ℃, oxygen supply is stopped, slag is not poured, and the strength of bottom-blown argon is 0.075Nm 3 /(min. T), hold time 2.3min.
The carbon content and the phosphorus content are respectively measured to be 0.025 percent and 0.0029 percent after slag tapping before and after the sliding plate is adopted to block the slag.
Example 3
The smelting method of the ultra-low phosphorus steel converter comprises the following steps:
molten iron having a phosphorus content of 0.145% was poured into the converter in an amount of 187 tons, and 38 tons of scrap steel was added to the converter and mixed to obtain molten steel. The total oxygen supply was controlled to 9639m 3 . And then the following operations are carried out on the molten steel in sequence:
(1) And (3) secondary blowing: the oxygen lance position is controlled to be 1.7m, and the top blowing oxygen flow is controlled to be 48000m 3 The oxygen pressure is controlled to be 0.98MPa, argon is blown from the bottom in the whole process, and the intensity of the supplied argon is 0.042Nm 3 /(min·t)。
(2) First slagging: 12kg/t of iron ore and 20kg/t of lime are added into the furnace. The temperature in the furnace is 1390 ℃, and the binary alkalinity is 2.0. When oxygen blowing amount of the oxygen lance reaches 14 percent of total oxygen supply amount, 1350m 3 Then the oxygen gun position was adjusted to 2.0m.
(3) Deslagging: 4338m when the oxygen lance blows oxygen to 45 percent of the total oxygen supply 3 When the furnace mouth begins to jump slag, the oxygen lance is lifted to the upper part of the furnace mouth, the converter is tilted to 60 degrees to pour early-stage slag, and the temperature of semisteel in the converter is determined to be 1375 ℃.
(4) And (3) continuous blowing: the oxygen lance was positioned at 2.1m and the converter was continued at a flow rate of 48000m 3 Oxygen top blowing at 0.98MPa and argon bottom blowing in the whole process, wherein the argon supply intensity is still 0.042Nm 3 /(min·t)。
(5) And (3) slagging for the second time: 30 kg of lime is added into the furnace, 10kg of the iron ore is added, the temperature in the furnace is 1579 ℃, and the binary alkalinity is 3.38.
(6) Post-blowing: the oxygen lance was positioned at 2.1m and the converter was continued at a flow rate of 48000m 3 Oxygen top blowing at 0.98MPa and argon bottom blowing in the whole process, wherein the argon supply intensity is still 0.080Nm 3 /(min·t)。
(7) And (3) end point control: the carbon content is measured to be 0.037 percent, the temperature of the molten steel is 1570 ℃, the oxygen supply is stopped, the slag is not poured, and the intensity of bottom-blown argon is 0.080Nm 3 /(min. T), hold time 2.67min.
The carbon content and the phosphorus content of the steel are respectively measured to be 0.025% and 0.0028% before and after the slag tapping of the sliding plate is adopted.
Comparative example 1
Steering gearMolten iron with the phosphorus content of 0.160 percent is poured into the converter, the weight of the molten iron is 99t, 11t of scrap steel is added into the converter, and the molten steel is obtained by mixing. The total oxygen supply amount is controlled to 5067m 3 And then the following operations are carried out on the molten steel in sequence:
(1) Re-blowing: the oxygen gun position is controlled to be 1.3m, and the flow of top-blown oxygen is controlled to be 21500m 3 The oxygen pressure is controlled to be 0.84MPa, argon is blown from the bottom in the whole process, and the intensity of the supplied argon is 0.03Nm 3 /(min·t)。
(2) First slagging: 20kg/t of iron ore and 25kg/t of lime are added into the furnace. The temperature in the furnace is 1370 ℃, and the binary alkalinity is 1.7m. When the oxygen blowing amount of the oxygen lance reaches 12 percent of the total oxygen supply amount, 673m 3 Then the oxygen lance position was adjusted to 1.7m.
(3) Deslagging: 9675m when the oxygen lance blows oxygen to 45 percent of the total oxygen supply amount 3 When the furnace mouth begins to jump slag, the oxygen lance is lifted to the upper part of the furnace mouth, the converter is tilted to 60 degrees to pour early-stage slag, and the temperature of semisteel in the converter is determined to be 1370 ℃.
(4) And (3) continuous blowing: the oxygen lance was positioned at 1.7m and the converter was continued at a flow rate of 21500m 3 The oxygen top blowing at 0.83MPa and the argon bottom blowing in the whole process, wherein the intensity of the argon supply is still 0.03Nm 3 /(min·t)。
(5) And (3) slagging for the second time: and adding 25kg of lime into the furnace, adding 10kg of iron ore into the furnace, wherein the temperature in the furnace is 1570 ℃, and the binary alkalinity is 3.25.
(6) Post-blowing: the oxygen lance was positioned at 1.65m and the converter was continued at a flow rate of 21500m 3 The oxygen top blowing at 0.83MPa and the argon bottom blowing in the whole process, wherein the intensity of the argon supply is still 0.03Nm 3 /(min·t)。
The slag blocking tap is used for slag blocking and tapping by adding a slag blocking rod, and the phosphorus element content of the molten steel in the converter is 0.012 percent and the carbon content is 0.32 percent.
Comparative example 2
The smelting method of the ultra-low phosphorus steel converter comprises the following steps:
molten iron with the phosphorus content of 0.155 percent is poured into the converter, the weight of the molten iron is 190t, and simultaneously, 30t of scrap steel is added into the converter to be mixed to obtain molten steel. Controlling the total oxygen supply amount to 9759m 3 And then the following operations are carried out on the molten steel in sequence:
(1) And (3) secondary blowing: the oxygen lance position is controlled to be 1.7m, and the top-blown oxygen flow is 52000m 3 The oxygen pressure is controlled to be 1.03MPa, argon is blown from the bottom in the whole process, and the intensity of the supplied argon is 0.01Nm 3 /(min·t)。
(2) First slagging: 7kg/t of iron ore and 15kg/t of lime are added into the furnace. The temperature in the furnace is 1450 ℃, and the binary alkalinity is 1.4. 781m when oxygen blowing amount of oxygen lance reaches 8% of total oxygen supply amount 3 Then the oxygen gun position was adjusted to 1.6m.
(3) Deslagging: when oxygen is blown by an oxygen lance until the furnace mouth begins to jump slag at 45 percent of the total oxygen supply amount, the oxygen lance is lifted to the upper part of the furnace mouth, the converter is tilted to 60 degrees to pour early-stage slag, and the temperature of semisteel in the converter is determined to be 1450 ℃.
(4) And (3) continuous blowing: the oxygen lance was positioned at 1.65m and the converter was continued at a flow rate of 52000m 3 Oxygen top blowing at a pressure of 1.03MPa and argon bottom blowing in the whole process, wherein the intensity of the supplied argon is still 0.01Nm 3 /(min·t)。
(5) And (3) slagging for the second time: 35kg/t of lime is added into the furnace, 7kg/t of iron ore is added, the temperature in the furnace is 1600 ℃, and the binary alkalinity is 3.5.
(6) Post-blowing: the oxygen lance was positioned at 1.65m and the converter was continued at a flow rate of 52000m 3 The oxygen top blowing at 1.03MPa and the argon bottom blowing in the whole process, wherein the argon supply intensity is still 0.04Nm 3 /(min·t)。
(7) And (3) end point control: measuring the carbon content to be 0.05 percent, the molten steel temperature to be 1600 ℃, stopping oxygen supply and not deslagging, and the strength of bottom blowing argon to be 0.04Nm 3 /(min. T), hold time 2min.
The carbon content and the phosphorus content of the steel after slag tapping before and after the sliding plate is adopted for blocking are respectively determined to be 0.04 percent and 0.009 percent.
As can be seen from the above examples and comparative examples, the content of phosphorus in the molten steel can be controlled to be below 0.004% by accurately controlling oxygen and controlling the binary alkalinity of slag, and combining early deslagging and effective end point control.
In conclusion, the invention provides a method for smelting ultra-low phosphorus steel in a converter, and the phosphorus content of molten steel produced by the smelting method is below 0.004 percent by mass. The method mainly determines the slag pouring time through oxygen blowing amount, avoids fluctuation of manual pure experience control, controls the alkalinity and the oxidability of early-stage slag and the temperature of semisteel in a furnace by adjusting the adding amount of lime and iron ore, ensures early-stage dephosphorization effect, and reduces subsequent dephosphorization pressure. By utilizing the characteristics of high oxidizability, high alkalinity and large slag amount at the end point, after oxygen supply is stopped, bottom blowing argon is combined to stir slag and molten steel, and a steel slag reaction interface is increased to further dephosphorize.
The above-mentioned embodiments are intended to illustrate the objects, technical solutions and advantages of the present invention in further detail, and it should be understood that the above-mentioned embodiments are only exemplary embodiments of the present invention, and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.
Claims (10)
1. The smelting method of the ultra-low phosphorus steel converter is characterized by comprising the following steps: mixing molten iron and scrap steel to obtain molten steel, and sequentially carrying out combined blowing, primary slagging, deslagging, continuous blowing, secondary slagging, post-blowing and end point control on the molten steel to obtain molten steel;
the mass content of phosphorus element in the molten steel is below 0.004%;
the oxygen flow in the secondary blowing process is 45000m 3 /h-50000m 3 /h；
The oxygen pressure in the secondary blowing process is 0.90MPa-1.0MPa;
the intensity of argon supplied in the combined blowing process is 0.02Nm 3 /(min·t)-0.08Nm 3 /(min·t)；
The oxygen flow in the continuous blowing process is 45000m 3 /h-50000m 3 /h；
The oxygen pressure in the continuous blowing process is 0.90MPa-1.0MPa;
the intensity of argon supplied in the continuous blowing process is 0.02Nm 3 /(min·t)-0.08Nm 3 /(min·t)。
2. The converter smelting method of the ultra-low phosphorus steel according to claim 1, characterized in thatThe intensity of argon supplied in the end point control process is 0.06Nm 3 /(min·t)-0.08Nm 3 /(min·t)；
And the time for supplying argon in the end point control process is 2min-3min.
3. The converter smelting method of ultra-low phosphorus steel according to claim 1, wherein the carbon content in the molten steel after post-blowing is 0.03-0.06%, and the temperature is 1560-1580 ℃.
4. The converter smelting method of ultra-low phosphorus steel according to claim 1, wherein the intensity of argon supplied in the post-blowing process is 0.02Nm 3 /(min·t)-0.08Nm 3 /(min·t)；
The oxygen flow in the post-blowing process is 45000m 3 /h-50000m 3 /h；
The oxygen pressure in the post-blowing process is 0.90MPa-1.0MPa.
5. The converter smelting method of the ultra-low phosphorus steel according to claim 1, wherein the amount of the iron ore added in the first slagging is 10kg/t-15kg/t;
the lime adding amount in the first slag making is 20kg/t-25kg/t.
6. The converter smelting method of ultra-low phosphorus steel according to claim 1, wherein the temperature of the first slagging is 1350-1400 ℃.
7. The converter smelting method of the ultra-low phosphorus steel according to claim 1, wherein the binary basicity of the first slagging is 1.6-2.0.
8. The converter smelting method of the ultra-low phosphorus steel as claimed in claim 1, wherein the temperature of the second slagging is 1560 ℃ -1580 ℃.
9. The converter smelting method of ultra-low phosphorus steel according to claim 1, wherein the binary basicity of the secondary slagging is 3.2-3.4.
10. The converter smelting method of the ultra-low phosphorus steel according to claim 1, wherein the weight fraction of the scrap steel in the molten steel is 10% -25%.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211543867.2A CN115747406A (en) | 2022-12-01 | 2022-12-01 | Ultra-low phosphorus steel converter smelting method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211543867.2A CN115747406A (en) | 2022-12-01 | 2022-12-01 | Ultra-low phosphorus steel converter smelting method |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN115747406A true CN115747406A (en) | 2023-03-07 |
Family
ID=85342956
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211543867.2A Pending CN115747406A (en) | 2022-12-01 | 2022-12-01 | Ultra-low phosphorus steel converter smelting method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115747406A (en) |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100749023B1 (en) * | 2006-05-26 | 2007-08-14 | 주식회사 포스코 | Method for refining extra low phosphorous steel in converter |
| CN106636531A (en) * | 2016-11-16 | 2017-05-10 | 南京钢铁股份有限公司 | Double-slag process for smelting ultralow-phosphorus and low-carbon steel in combined-blown converter |
| CN107699656A (en) * | 2015-08-31 | 2018-02-16 | 合肥智慧龙图腾知识产权股份有限公司 | A kind of ultra-low phosphoretic steel smelting process |
| CN108265150A (en) * | 2018-02-28 | 2018-07-10 | 钢铁研究总院 | A kind of converter high-strength complex blows full raw material slagging method of double slag technique dephosphorization phases |
-
2022
- 2022-12-01 CN CN202211543867.2A patent/CN115747406A/en active Pending
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR100749023B1 (en) * | 2006-05-26 | 2007-08-14 | 주식회사 포스코 | Method for refining extra low phosphorous steel in converter |
| CN107699656A (en) * | 2015-08-31 | 2018-02-16 | 合肥智慧龙图腾知识产权股份有限公司 | A kind of ultra-low phosphoretic steel smelting process |
| CN106636531A (en) * | 2016-11-16 | 2017-05-10 | 南京钢铁股份有限公司 | Double-slag process for smelting ultralow-phosphorus and low-carbon steel in combined-blown converter |
| CN108265150A (en) * | 2018-02-28 | 2018-07-10 | 钢铁研究总院 | A kind of converter high-strength complex blows full raw material slagging method of double slag technique dephosphorization phases |
Non-Patent Citations (3)
| Title |
|---|
| 廖鹏;侯泽旺;秦哲;张兴中;仇圣桃;: "复吹转炉双渣吹炼脱磷试验", 钢铁, no. 01 * |
| 廖鹏;秦哲;侯泽旺;张兴中;仇圣桃;: "复吹转炉冶炼低磷钢试验研究", 钢铁钒钛, no. 04 * |
| 高志滨;: "非双联法冶炼低磷钢种工艺优化与实践", 山东冶金, no. 02 * |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN109280731B (en) | Method for producing steel with converter end point P less than or equal to 0.01% by smelting high-phosphorus molten iron by adopting less slag materials | |
| CN102747181B (en) | Smelting method of 9Ni steel | |
| CN102329921B (en) | Semi-steel making method | |
| CN115323099B (en) | Steelmaking method for recycling magnetic separation steel slag by converter | |
| JP3239197B2 (en) | Converter steelmaking method | |
| CN114150100B (en) | Steelmaking method for smelting high-carbon low-phosphorus steel by converter | |
| CN108913834B (en) | Process for producing high-purity pig iron by molten iron blowing, vacuum degassing and electrode heating | |
| CN113832289A (en) | Method for improving converter double-slag once-reversing dephosphorization rate | |
| CN110527786B (en) | Method for directly alloying and steelmaking by using manganese ore in converter | |
| JPS63195209A (en) | Steel making method | |
| CN110564908A (en) | double-slag dephosphorization and steel-making method for semisteel converter | |
| CN109280733A (en) | A kind of smelting process of dephosphorization converter terminal low phosphorus content molten steel | |
| CN114480773B (en) | Production control method for reducing production cycle of converter and improving production efficiency of converter | |
| CN109554515B (en) | Method for smelting stainless steel by top-blown converter | |
| CN115747406A (en) | Ultra-low phosphorus steel converter smelting method | |
| CN108676954A (en) | A kind of interior dephosphorization method for making steel recycled of converter steel slag hearth | |
| CN105483315B (en) | The method of chrome ore DIRECT ALLOYING in semi-steel making Converter | |
| JP2003239009A (en) | Dephosphorization refining method of hot metal | |
| CN108796162B (en) | Rapid dephosphorization method for semisteel smelting converter and steelmaking method | |
| JPH08311519A (en) | Steelmaking method using converter | |
| CN111020115A (en) | Method for refining molten steel outside furnace by using liquid blast furnace slag | |
| JPH0557327B2 (en) | ||
| CN112458237B (en) | Steelmaking method for reducing slag quantity and modifying slag components on line | |
| CN115558735B (en) | Smelting method of pure iron | |
| JPH0377246B2 (en) |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination |