CN113652523B - Method for dephosphorizing molten steel in LF refining process - Google Patents
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
- C21C7/04—Removing impurities by adding a treating agent
- C21C7/064—Dephosphorising; Desulfurising
- C21C7/0645—Agents used for dephosphorising or desulfurising
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- C21C—PROCESSING OF PIG-IRON, e.g. REFINING, MANUFACTURE OF WROUGHT-IRON OR STEEL; TREATMENT IN MOLTEN STATE OF FERROUS ALLOYS
- C21C7/00—Treating molten ferrous alloys, e.g. steel, not covered by groups C21C1/00 - C21C5/00
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- C22C38/14—Ferrous alloys, e.g. steel alloys containing titanium or zirconium
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Abstract
The invention discloses a method for dephosphorizing molten steel in an LF refining process, wherein after the molten steel enters an LF refining furnace, 2.8-3.2 kg/t of lime is added, oxygen is blown for 3-4 minutes, and the oxygen flow is 240-260 NL/min; the temperature of the molten steel is raised to 1590-1600 ℃, the temperature is kept for 7-9 minutes, and no deoxidation alloy material is added in the period; and after LF refining is carried out for 13-15 minutes, quickly raising the temperature to 1617-1622 ℃ within 120 seconds through arc heating, and keeping the temperature for 3-5 minutes to complete dephosphorization in the LF furnace. When the method is adopted to produce the low-phosphorus steel, the upper limit of the used molten iron P can be increased to 0.160 percent, and the production is basically not influenced by the molten iron condition; the smelting period of the converter is basically about 35 minutes, so that the production efficiency is greatly improved; in the LF smelting process, the removal rate of the phosphorus element is over 50 percent, and the method plays a great role in promoting the production of low-phosphorus steel products.
Description
Technical Field
The invention belongs to the field of steelmaking, and relates to a molten steel dephosphorization method in an LF refining process.
Background
Phosphorus is a harmful element in steel, can improve the strength of the steel by a small amount, but greatly reduces the plasticity and the toughness of the steel and increases the sensitivity of welding cracks. Meanwhile, phosphorus is easy to segregate, so that the banded structure of steel is aggravated, and the influence on the performance of the steel is great, so that the lower the phosphorus content is, the better the phosphorus content is, in the smelting process of most of steel, but P in molten steel is difficult to effectively remove due to the restriction of various factors in the smelting process. According to the statistics of relevant data, the content of phosphorus in molten steel is difficult to remove to be less than 100ppm in most cases, and the low-temperature performance yield of steel products with high requirements on low-temperature toughness is seriously influenced. At present, most iron and steel enterprises dephosphorize in the converter process, LF refining mainly has the functions of molten steel temperature rise, desulfurization, component fine adjustment and molten steel cleanliness improvement, and phosphorus content in the LF refining process cannot be removed and is partially increased.
Chinese patent document CN 112195309A (202010870303.4) discloses a LF furnace smelting process with deep dephosphorization function. The patent mainly controls the oxygen partial pressure of the steel slag interface and P in molten steel by adding a reduction dephosphorization agent and utilizing LF reducing atmosphere 3+ Further deep threshing. The patent adopts reductive dephosphorization, and has high cost and difficult operation. In addition, according to the descriptions of the patent examples 1 to 3, the method further performs LF reduction deep dephosphorization after depp treatment and RH treatment immediately after the tapping in the converter, and the process is complicated and high in cost, and is not suitable for popularization and use in the smelting of general steel.
Chinese patent document CN105039647A (201510348833.1) discloses a dephosphorization refining method of an LF furnace, which comprises the following steps: (1) After molten steel enters an LF furnace, a ladle bottom blowing pipe and an external oxygen source are connected, bottom blowing oxygen is switched to an argon source after 40-42 s, and argon is bottom blown in the whole refining process; (2) power transmission and slagging: adding the following slag making materials before power transmission: 9 to 10Kg/t of converter particle steel, 1.5 to 2.8Kg/t of ore and 2Kg/t of fluorite are conveyed to the furnace slag for thorough melting; the converter granulated steel is crushed particles after the converter end-point slag returns to natural cooling, and the main components of the converter granulated steel are CaO 45-49 percent, feO 14-20 percent and impurities in percentage by mass; (3) After the slag is completely melted, the power is cut off, the flow of bottom blowing argon is increased to 800-850 NL/min, the gas is adopted for stirring for 10-15 min, 1-1.5 Kg/t of converter particle steel, 1-1.5 Kg/t of ore and 1Kg/t of fluorite powder are added in the stirring process and spread to the slag layer for dephosphorization; (4) After dephosphorization is finished, 1.5-2 Kg/t of lime is added to prevent rephosphorization. However, the method of controlling dephosphorization by changing the slagging method is poor in operability and low in dephosphorization rate which is only 16%.
Disclosure of Invention
The invention provides a novel molten steel dephosphorization method in an LF refining process, aiming at the problem of difficult dephosphorization in the LF refining process in the prior art. The method is reasonable, the production process is simple to control, the dephosphorization efficiency is high, the effect is good, and the product quality is stable.
In order to achieve the purpose, the invention adopts the following technical scheme:
a method for dephosphorizing molten steel in an LF refining process is characterized in that,
after molten steel enters an LF refining furnace, adding 2.8-3.2 kg/t of lime, blowing oxygen for 3-4 minutes, and controlling the oxygen flow rate to be 240-260 NL/min; the temperature of the molten steel is raised to 1590-1600 ℃, the temperature is kept for 7-9 minutes, and no deoxidation alloy material is added in the period;
and after 13-15 minutes of LF refining (the LF refining time is calculated from the beginning of oxygen blowing), rapidly raising the temperature to 1617-1622 ℃ within 120 seconds by arc heating, and keeping the temperature for 3-5 minutes to complete dephosphorization in the LF furnace.
Preferably, in the above method, the molten iron raw material used comprises the following components: 3.5-5.0%, mn:0.15-0.30%, si:0.18 to 0.32%, P: 0.130-0.160%, S:0.015 to 0.025 percent, and the balance of Fe and inevitable impurities.
Preferably, the molten steel before refining in the LF furnace (namely, the molten steel after smelting in the converter) comprises the following components: c: 0.070-0.160%, mn:0.85 to 1.60%, si:0.10 to 0.40%, P: 0.011-0.018%, S: 0.009-0.013%, nb: 0.005-0.060%, V:0.005% -0.070%, ni: 0.010-0.500%, and the balance of Fe and inevitable impurities.
Preferably, after molten steel is dephosphorized in an LF furnace, 1.9-2.1 kg/t of deoxidizer is added, LF refining treatment is carried out for 18-23 minutes, and a proper amount of alloy is added for component fine adjustment according to the component requirement of steel; then feeding a calcium silicate wire for 160-200m, soft blowing for 15min, and controlling the temperature of the molten steel discharged from the LF station to be 1600-1610 ℃.
More preferably, the deoxidizer is an aluminum-magnesium-calcium composite deoxidizer.
Further preferably, the ingredients of the molten steel discharged from the LF station are: c:0.080 to 0.200%, mn:0.90 to 1.70%, si: 0.15-0.55%, S is less than or equal to 0.005%, P is less than or equal to 0.007%, nb: 0.005-0.060%, V:0.005% -0.070%, ni: 0.010-0.500%, ti: 0.005-0.020%, ca: 0.005-0.010 percent, and the balance of Fe and inevitable impurities, which are all in percentage by mass.
According to the method, the step (1) not only completes dephosphorization operation, but also the step (2) is normal LF refining treatment, the operation is simple, the dephosphorization operation in the LF refining process can be realized only by controlling factors such as oxygen blowing flow, time, molten steel temperature and the like, and the method is convenient, simple and convenient.
The method has the advantages of reasonableness, simple control of production process, high dephosphorization efficiency, good effect, stable control of P content within 70ppm and stable product quality.
The invention has at least the following beneficial effects:
(1) In the prior art, when the steel with P less than or equal to 0.010 percent is produced, the content of P in molten iron is required to be controlled within 0.130 percent; compared with the conventional smelting production process, the method increases the early-stage dephosphorization process of the LF, so that the upper limit of the used molten iron P can be increased to 0.160 percent when the low-phosphorus steel is produced, and the production is basically not influenced by the molten iron conditions;
(2) The production pressure of the converter is reduced, the smelting time for smelting the low-phosphorus steel by the converter is generally over 45 minutes before the method is adopted, and the smelting period of the converter is basically about 35 minutes after the method is adopted, so that the production efficiency is greatly improved;
(3) Before the method is adopted, the phosphorus content in the LF smelting process can not be controlled, even can be increased to a certain extent, and after the method is adopted, the removal rate of phosphorus elements in the LF smelting process is over 50 percent, so that the method plays a great role in promoting the production of low-phosphorus steel products.
Detailed Description
The technical solution of the present invention is further explained by the following examples.
Example 1
A method for dephosphorizing molten steel in an LF refining process comprises the following steps:
(1) Raw material composition of molten iron
4.2 percent of C, 0.26 percent of Mn, 0.24 percent of Si, 0.153 percent of P, 0.019 percent of S, and the balance of Fe and inevitable impurities;
(2) Molten steel composition after converter smelting
0.120% of C, 1.41% of Mn, 0.31% of Si, 0.016% of P, 0.010% of S, nb:0.028%, V:0.026%, ni:0.17 percent, the balance of Fe and inevitable impurities, and the converter tapping amount is 137 tons;
(3) LF refining process
Adding 411kg of lime into a steel ladle when the steel ladle enters a station, blowing oxygen for 3.5 minutes, wherein the oxygen flow is as follows: 250NL/min; raising the temperature to 1595 ℃, and keeping the temperature for 7 minutes, wherein no deoxidized alloy material is added in the period; the LF smelting is carried out for 14 minutes, the temperature is quickly raised to 1620 ℃ and kept for 4 minutes, then 274kg of aluminum-magnesium-calcium composite deoxidizer, 50kg of silicon-manganese alloy, 15kg of Nb iron and 300m of Ti wire are added, the LF refining treatment is carried out for 21 minutes, 200m of silicon-calcium wire is fed, 15min of soft blowing is carried out, and the temperature of the molten steel discharged from the LF is 1607 ℃;
the LF outlet molten steel comprises the following components in percentage by mass: 0.135%, mn:1.42%, si:0.32%, S:0.003%, P:0.007%, nb:0.029%, V:0.026%, ni:0.17%, ti:0.013%, ca:0.006% and the balance of Fe and inevitable impurities.
The calculation shows that the dephosphorization rate of LF refining is 56.25%.
Example 2
A method for dephosphorizing molten steel in an LF refining process comprises the following steps:
(1) Raw material composition of molten iron
4.17 percent of C, 0.29 percent of Mn, 0.22 percent of Si, 0.145 percent of P, 0.017 percent of S and the balance of Fe and inevitable impurities;
(2) Molten steel composition after converter smelting
0.131% of C, 1.37% of Mn, 0.29% of Si, 0.013% of P, 0.011% of S, nb:0.030%, V:0.024%, ni:0.15 percent, the balance of Fe and inevitable impurities, and the converter tapping amount is 135 tons;
(3) LF refining
Adding 405kg of lime into a steel ladle entering a station, blowing oxygen for 3 minutes, wherein the oxygen flow is as follows: 250NL/min; raising the temperature to 1595 ℃, keeping the temperature for 8 minutes, and not adding any deoxidation alloy material in the period; the LF smelting is carried out for 13 minutes, the temperature is quickly raised to 1620 ℃, the temperature is kept for 3 minutes, then 270kg of aluminum-magnesium-calcium composite deoxidizer, 70kg of silicon-manganese alloy, 12kg of ferroniobium, 20kg of ferrovanadium and 300m of titanium wire are added, the LF refining treatment is carried out for 19 minutes, 200m of silicon-calcium wire is fed, the soft blowing is carried out for 15min, the LF outlet molten steel temperature is as follows: 1610 ℃;
the LF outlet molten steel comprises the following components in percentage by mass: 0.134%, mn:1.40%, si:0.30%, S:0.002%, P:0.005%, nb:0.031%, V:0.026%, ni:0.15%, ti:0.014%, ca:0.005% and the balance of Fe and inevitable impurities;
the calculation shows that the dephosphorization rate of LF refining is 61.54%.
Example 3
A method for dephosphorizing molten steel in an LF refining process comprises the following steps:
(1) Raw material composition of molten iron
3.95 percent of C, 0.26 percent of Mn, 0.20 percent of Si, 0.160 percent of P, 0.020 percent of S, and the balance of Fe and inevitable impurities;
(2) Molten steel composition after converter smelting
0.140% of C, 1.43% of Mn, 0.33% of Si, 0.017% of P, 0.012% of S, nb:0.025%, V:0.030%, ni:0.18 percent, the balance of Fe and inevitable impurities, and 139 tons of converter tapping amount;
(3) LF refining
417kg of high-quality lime is added when a steel ladle enters a station, oxygen is blown for 4 minutes, and the oxygen flow is as follows: 250NL/min; raising the temperature to 1595 ℃, keeping the temperature for 9 minutes, and not adding any deoxidation alloy material in the period; LF smelting is carried out for 15 minutes, the temperature is quickly raised to 1620 ℃, the temperature is kept for 3 minutes, then aluminum-magnesium-calcium composite deoxidizer 278kg, nb iron 30kg, ti wire 330m, LF refining treatment is carried out for 23 minutes, silicon-calcium wire feeding is carried out for 200m, soft blowing is carried out for 15min, and the temperature of LF outlet molten steel is as follows: 1605 deg.C;
the LF outlet molten steel comprises the following components in percentage by mass: 0.143%, mn:1.43%, si:0.33%, S:0.001%, P:0.007%, nb:0.028%, V:0.030%, ni:0.18%, ti:0.015%, ca:0.008% and the balance of Fe and inevitable impurities;
the calculation shows that the dephosphorization rate of LF refining is 58.82%.
Comparative example 1
A method for dephosphorizing molten steel in an LF refining process comprises the following steps:
(1) Raw material composition of molten iron
4.0 percent of C, 0.25 percent of Mn, 0.27 percent of Si, 0.152 percent of P, 0.017 percent of S and the balance of Fe and inevitable impurities; (2) Molten steel composition after converter smelting
0.116% of C, 1.39% of Mn, 0.30% of Si, 0.017% of P, 0.009% of S, nb:0.027%, V:0.028%, ni:0.18 percent, the balance of Fe and inevitable impurities, and the converter tapping amount is 138 tons;
(3) LF refining
417kg of high-quality lime is added when a steel ladle enters a station, oxygen is blown for 2.5 minutes, and the oxygen flow is as follows: 250NL/min; raising the temperature to 1595 ℃, and keeping the temperature for 7 minutes, wherein no deoxidized alloy material is added in the period; LF smelting is carried out for 14 minutes, the temperature is quickly raised to 1620 ℃, the temperature is kept for 4 minutes, then 276kg of aluminum-magnesium-calcium composite deoxidizer, 90kg of silicon-manganese alloy, 14kg of Nb iron, 310m of Ti wire are added, LF refining treatment is carried out for 21 minutes, 200m of silicon-calcium wire is fed, soft blowing is carried out for 15min, and the temperature of molten steel discharged from an LF station is 1608 ℃;
the LF outlet molten steel comprises the following components in percentage by mass: 0.125%, mn:1.43%, si:0.31%, S:0.003%, P:0.016%, nb:0.028%, V:0.028%, ni:0.18%, ti:0.014%, ca:0.005% and the balance of Fe and inevitable impurities;
the calculated dephosphorization rate of LF refining is 5.88%.
Comparative example 2
A method for dephosphorizing molten steel in an LF refining process comprises the following steps:
(1) Raw material composition of molten iron
(1) Raw material composition of molten iron
4.21 percent of C, 0.28 percent of Mn, 0.23 percent of Si, 0.146 percent of P, 0.015 percent of S and the balance of Fe and inevitable impurities;
(2) Molten steel composition after converter smelting
0.133% of C, 1.38% of Mn, 0.27% of Si, 0.013% of P, 0.010% of S, nb:0.030%, V:0.025%, ni:0.15 percent, the balance of Fe and inevitable impurities, and the converter tapping amount is 135 tons;
(3) LF refining
Adding 405kg of high-quality lime into a steel ladle when the steel ladle enters a station, blowing oxygen for 3.3 minutes, wherein the oxygen flow rate is as follows: 230NL/min; raising the temperature to 1595 ℃, keeping the temperature for 8 minutes, and not adding any deoxidized alloy material in the period; LF smelting is carried out for 13 minutes, the temperature is quickly raised to 1620 ℃, the temperature is kept for 3 minutes, then 270kg of aluminum-magnesium-calcium composite deoxidizer, 90kg of silicon-manganese alloy, 29kg of ferrovanadium and 290m of Ti wire are added, LF refining treatment is carried out for 19 minutes, 200m of silicon-calcium wire is fed, soft blowing is carried out for 15min, and the temperature of molten steel discharged from an LF station is as follows: 1610 ℃;
the LF outlet molten steel comprises the following components in percentage by mass: 0.133%, mn:1.41%, si:0.30%, S:0.002%, P: 0.012%, nb:0.030%, V:0.027%, ni:0.15%, ti:0.013%, ca:0.006% of Fe and the balance of inevitable impurities;
the calculated dephosphorization rate of LF refining is 7.70%.
Comparative example 3
A method for dephosphorizing molten steel in an LF refining process comprises the following steps:
(1) Raw material composition of molten iron
3.97 percent of C, 0.26 percent of Mn, 0.21 percent of Si, 0.159 percent of P, 0.018 percent of S and the balance of Fe and inevitable impurities;
(2) Molten steel composition after converter smelting
0.141% of C, 1.44% of Mn, 0.32% of Si, 0.017% of P, 0.011% of S, nb:0.025%, V:0.029%, ni:0.18 percent, the balance of Fe and inevitable impurities, and the converter tapping amount is 140 tons;
(3) LF refining
422kg of high-quality lime is added when a steel ladle enters a station, oxygen is blown for 4 minutes, and the oxygen flow is as follows: 250NL/min; raising the temperature to 1585 ℃, and keeping the temperature for 9 minutes, wherein no deoxidation alloy material is added in the process; and (2) smelting for 15 minutes in an LF (ladle furnace), rapidly raising the temperature to 1620 ℃, keeping the temperature for 3 minutes, then adding 280kg of aluminum-magnesium-calcium composite deoxidizer, 28kg of Nb iron, 320m of Ti wire, refining for 22 minutes in an LF (ladle furnace), feeding 200m of silicon-calcium wire, soft blowing for 15min, and tapping at the temperature of molten steel in an LF (ladle furnace): 1605 deg.C;
the LF outgoing molten steel comprises the following components in percentage by mass: 0.142%, mn:1.44%, si:0.32%, S:0.001%, P:0.016%, nb:0.028%, V:0.029%, ni:0.18%, ti:0.014%, ca:0.007% and the balance of Fe and inevitable impurities;
the calculation shows that the dephosphorization rate of LF refining is 5.88%.
Comparative example 4
A method for dephosphorizing molten steel in an LF refining process comprises the following steps:
(1) Raw material composition of molten iron
3.99 percent of C, 0.26 percent of Mn, 0.22 percent of Si, 0.160 percent of P, 0.017 percent of S and the balance of Fe and inevitable impurities;
(2) Molten steel composition after converter smelting
0.140% of C, 1.44% of Mn, 0.33% of Si, 0.018% of P, 0.014% of S, nb:0.027%, V:0.029%, ni:0.17 percent, the balance of Fe and inevitable impurities, and 139 tons of converter tapping amount;
(3) LF refining
417kg of high-quality lime is added when the steel ladle enters the station, oxygen blowing is carried out for 4 minutes, and the oxygen flow is as follows: 250NL/min; raising the temperature to 1595 ℃, and keeping the temperature for 5 minutes, wherein no deoxidized alloy material is added in the period; the LF smelting is carried out for 15 minutes, the temperature is quickly raised to 1620 ℃, the temperature is kept for 3 minutes, 278kg of aluminum-magnesium-calcium composite deoxidizer, 25kg of silicon-manganese alloy, 25kg of Nb iron, 12kg of vanadium iron and 300m of Ti wire are added, the LF refining treatment is carried out for 22 minutes, 200m of silicon-calcium wire is fed, 15min of soft blowing is carried out, the temperature of the molten steel discharged from the LF station is as follows: 1605 deg.C;
the LF outlet molten steel comprises the following components in percentage by mass: 0.141%, mn:1.45%, si:0.33%, S:0.002%, P:0.016%, nb:0.029%, V:0.030%, ni:0.17%, ti:0.013%, ca:0.006% of Fe and the balance of inevitable impurities;
the calculation shows that the dephosphorization rate of LF refining is 11.11%.
According to the method for dephosphorizing molten steel in the LF refining process, factors such as oxygen blowing time, oxygen flow, temperature after oxygen blowing, temperature maintaining time and the like are controlled, so that O, ca and P are controlled to react to generate calcium and phosphorus oxides, [ O ] + [ Ga ] + [ P ] → CaPxOy, and the density of the products is less than that of the molten steel and can float upwards to be absorbed by a slag layer on the surface of a steel ladle. The molten steel dephosphorization method in the refining process can be realized, molten iron with the phosphorus content of 0.130-0.160 percent can be used for smelting steel with the phosphorus content of less than 0.007 percent, the production pressure of a converter is reduced, the production efficiency is improved, and the product quality is improved.
Claims (3)
1. A method for dephosphorizing molten steel in an LF refining process is characterized in that,
(1) The molten iron comprises the following raw material components: c:3.5-5.0%, mn:0.15-0.30%, si:0.18 to 0.32%, P:0.130 to 0.160%, S:0.015 to 0.025 percent, and the balance of Fe and inevitable impurities;
(2) Molten steel components before refining in an LF furnace: c:0.070 to 0.160%, mn:0.85 to 1.60%, si:0.10 to 0.40%, P:0.011 to 0.018%, S:0.009 to 0.013%, nb: 0.005-0.060%, V:0.005% -0.070%, ni: 0.010-0.500 percent, and the balance of Fe and inevitable impurities;
(3) And LF refining: after molten steel enters an LF refining furnace, adding lime for 2.8-3.2kg/t, blowing oxygen for 3-4 minutes, and controlling the oxygen flow for 240-260NL/min; raising the temperature of the molten steel to 1590-1600 ℃, and keeping the temperature for 7-9 minutes, wherein no deoxidizing alloy material is added in the period; after LF refining is carried out for 13 to 15 minutes, arc heating is carried out, the temperature is quickly raised to 1617 to 1622 ℃ within 120 seconds, the temperature is kept for 3 to 5 minutes, and dephosphorization in an LF furnace is completed;
after molten steel is dephosphorized in an LF furnace, adding 1.9-2.1kg/t deoxidizer, and carrying out LF refining treatment for 18-23 minutes, wherein a proper amount of alloy is added for fine adjustment according to steel components; then feeding a calcium silicon wire for 160-200m, soft blowing for 15min, and controlling the temperature of the molten steel at the LF station outlet to be 1600-1610 ℃.
2. The method according to claim 1, wherein the deoxidizer is an aluminum magnesium calcium complex deoxidizer.
3. The method of claim 1, wherein the LF outbound molten steel composition is: c:0.080 to 0.200%, mn:0.90 to 1.70%, si: 0.15-0.55%, S is less than or equal to 0.005%, P is less than or equal to 0.007%, nb: 0.005-0.060%, V:0.005% -0.070%, ni: 0.010-0.500%, ti: 0.005-0.020%, ca: 0.005-0.010 percent, and the balance of Fe and inevitable impurities, which are all in percentage by mass.
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| CN202110943119.2A CN113652523B (en) | 2021-08-17 | 2021-08-17 | Method for dephosphorizing molten steel in LF refining process |
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Citations (5)
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| CN105039647A (en) * | 2015-06-23 | 2015-11-11 | 武汉钢铁(集团)公司 | LF furnace shallow dephosphorization refining method |
| CN107299194A (en) * | 2017-07-30 | 2017-10-27 | 湖南华菱湘潭钢铁有限公司 | The method for making steel of dephosphorization after a kind of stove |
| CN110468248A (en) * | 2019-09-02 | 2019-11-19 | 湖南华菱湘潭钢铁有限公司 | A kind of method of dephosphorization after Converter |
| CN110484688A (en) * | 2019-10-08 | 2019-11-22 | 武汉钢铁集团鄂城钢铁有限责任公司 | A kind of shallow dephosphorization method of refining of the LF furnace of process for making |
| EP3686310A1 (en) * | 2018-05-23 | 2020-07-29 | Manchao He | Npr anchor rod steel material and production method therefor |
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| CN105039647A (en) * | 2015-06-23 | 2015-11-11 | 武汉钢铁(集团)公司 | LF furnace shallow dephosphorization refining method |
| CN107299194A (en) * | 2017-07-30 | 2017-10-27 | 湖南华菱湘潭钢铁有限公司 | The method for making steel of dephosphorization after a kind of stove |
| EP3686310A1 (en) * | 2018-05-23 | 2020-07-29 | Manchao He | Npr anchor rod steel material and production method therefor |
| CN110468248A (en) * | 2019-09-02 | 2019-11-19 | 湖南华菱湘潭钢铁有限公司 | A kind of method of dephosphorization after Converter |
| CN110484688A (en) * | 2019-10-08 | 2019-11-22 | 武汉钢铁集团鄂城钢铁有限责任公司 | A kind of shallow dephosphorization method of refining of the LF furnace of process for making |
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