CN111944955A - RH vacuum refining method - Google Patents
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- CN111944955A CN111944955A CN202010877895.2A CN202010877895A CN111944955A CN 111944955 A CN111944955 A CN 111944955A CN 202010877895 A CN202010877895 A CN 202010877895A CN 111944955 A CN111944955 A CN 111944955A
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- 238000007670 refining Methods 0.000 title claims abstract description 50
- 238000000034 method Methods 0.000 title claims abstract description 42
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 119
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 107
- 239000010959 steel Substances 0.000 claims abstract description 107
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 claims abstract description 68
- 229910052757 nitrogen Inorganic materials 0.000 claims abstract description 57
- 239000007789 gas Substances 0.000 claims abstract description 52
- 229910052786 argon Inorganic materials 0.000 claims abstract description 34
- 238000007664 blowing Methods 0.000 claims description 27
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 20
- 239000001301 oxygen Substances 0.000 claims description 20
- 229910052760 oxygen Inorganic materials 0.000 claims description 20
- 238000003723 Smelting Methods 0.000 claims description 19
- 230000008569 process Effects 0.000 claims description 17
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 12
- 229910052782 aluminium Inorganic materials 0.000 claims description 12
- 238000005086 pumping Methods 0.000 claims description 10
- 238000007872 degassing Methods 0.000 claims description 8
- 239000002893 slag Substances 0.000 claims description 7
- 238000005261 decarburization Methods 0.000 claims description 6
- 238000005275 alloying Methods 0.000 claims description 5
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 7
- 230000001174 ascending effect Effects 0.000 description 7
- 229910052799 carbon Inorganic materials 0.000 description 7
- 238000004519 manufacturing process Methods 0.000 description 7
- 229910045601 alloy Inorganic materials 0.000 description 4
- 239000000956 alloy Substances 0.000 description 4
- 229910001209 Low-carbon steel Inorganic materials 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000002360 explosive Substances 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- -1 on one hand Substances 0.000 description 2
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 229910002091 carbon monoxide Inorganic materials 0.000 description 1
- 238000010586 diagram Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 125000004435 hydrogen atom Chemical class [H]* 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
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Classifications
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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
- C21C7/10—Handling in a vacuum
-
- 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
- C21C7/072—Treatment with gases
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- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Treatment Of Steel In Its Molten State (AREA)
Abstract
The application discloses an RH vacuum refining method, wherein nitrogen and argon are sequentially adopted as circulating gas to guide molten steel to circularly flow for refining, wherein the duration of taking the nitrogen as the circulating gas is 1-7 min, and the nitrogen increasing amount of the molten steel is controlled to be below 7 ppm; the nitrogen increasing amount of the molten steel is controlled by firstly adding nitrogen as a circulating gas and controlling the circulating time of the nitrogen.
Description
Technical Field
The application belongs to the technical field of steel smelting, and particularly relates to an RH vacuum refining method.
Background
RH refining is one of the main processes of external refining, is a treatment process combining vacuum refining and molten steel circulating flow, and has the advantages of short treatment period, high production capacity, good refining effect and the like. The specific refining process is as follows: two dip pipes at the lower part of the vacuum chamber are inserted into the molten steel, one of the two dip pipes is an ascending pipe, the other is a descending pipe, the vacuum pump is started to vacuumize the vacuum chamber, pressure difference is formed between the inside and the outside of the vacuum chamber, circulating gas is blown into about one third of the lower part of the ascending pipe, a large amount of bubbles are generated in the ascending pipe and rapidly expand, and the expanded gas drives the molten steel to ascend. In a vacuum state, argon, hydrogen, carbon monoxide and other gases in the molten steel flowing through the vacuum chamber are pumped away in the molten steel circulation process, meanwhile, in order to meet the steel grade requirement, alloying treatment is required in the RH treatment process, and the molten steel entering the vacuum chamber is subjected to a series of metallurgical reactions.
In order to control the production cost of the circulating gas, nitrogen is generally adopted as the circulating gas, but the nitrogen content in the molten steel is too high, and the mechanical property of the finished steel product is poor.
Disclosure of Invention
In view of the above, the present application aims to provide an RH vacuum refining method to solve the problem of the prior art that the content of liquid nitrogen in steel is too high.
In order to achieve the purpose, the application provides an RH vacuum refining method, nitrogen and argon are sequentially adopted as circulating gas to guide molten steel to circularly flow for refining, wherein the duration of taking nitrogen as the circulating gas is 1-7 min, and the nitrogen increasing amount of the molten steel is controlled to be below 7 ppm.
Optionally, the time period of the nitrogen as the circulating gas is 5-7 min.
Optionally, the step of refining by guiding the molten steel to circularly flow by using nitrogen as a circulating gas includes:
the nitrogen gas is 95-105 m3Guiding the molten steel to circularly flow at the flow speed/h for degassing for 3-4 min;
the flow rate of the nitrogen is increased to 185-195 m3And h, continuously guiding the molten steel to circularly flow and degas for 2-3 min.
Optionally, the step of increasing the flow rate of the nitrogen gas further includes: when top lance oxygen blowing is carried out in the vacuum chamber, the flow of nitrogen in the process of top lance oxygen blowing is adjusted to 170-180 m3H, adjusting the flow rate of the nitrogen to 185-195 m after oxygen blowing3/h。
Optionally, the step of refining by guiding the molten steel to circularly flow by using argon as a circulating gas includes:
the argon gas is 185-195 m3/And h, enabling the molten steel to circularly flow and degas between a steel ladle and the vacuum chamber for 4-6 min at the flow velocity, keeping the oxygen content at the decarburization end point at 300-600 ppm, adding aluminum for deoxidation alloying, and adjusting the flow of argon to 145-155 m3/h until the smelting is finished.
Optionally, after adding aluminum, the argon gas is used for heating at 145-155 m3Guiding the molten steel to circularly flow and degas for 4-6 min at a flow speed of/h, adjusting the content of other components of the molten steel to the content of target components, and using argon gas at 145-155 m3And guiding the molten steel to circularly flow and degas for 4-8 min at the flow rate/h until the smelting is finished.
Optionally, the method further comprises:
starting a main valve for smelting, starting 5-stage pumping by a vacuum pump for more than 1min until the vacuum degree is 25000Pa or less, starting 4-stage pumping for more than 3min until the vacuum degree is 7500Pa or less, starting 3-stage pumping for more than 3.5min until the vacuum degree is 2000Pa or less, starting 2-stage pumping for more than 2min until the vacuum degree is 500Pa or less, and starting 1-stage pumping for more than 1min until the vacuum degree is 133Pa or less.
Optionally, before the step of refining by guiding the molten steel to circularly flow by sequentially using nitrogen and argon as circulating gas, the method further comprises:
the tightness of the RH vacuum refining device is checked, the air leakage condition in the RH vacuum refining process is avoided, and the vacuum degree can be guaranteed to be below 133 pa;
and lifting the steel ladle to a position in the steel ladle, wherein the slag surface is 400-600 mm higher than the end part of the lower opening of the dip pipe.
Compared with the prior art, the method has the following beneficial effects:
according to the embodiment of the application, nitrogen and argon are sequentially adopted as the circulating gas, on one hand, nitrogen is firstly added as the circulating gas, and the circulating time, the circulating flow rate and the vacuum degree of a vacuum chamber of the nitrogen are controlled, so that the nitrogen increasing amount of the molten steel is controlled; on the other hand, the nitrogen and the argon are sequentially used as the circulating gas, so that the production cost of using pure argon as the circulating gas can be reduced.
Drawings
In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or the prior art descriptions will be briefly described below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without inventive exercise.
FIG. 1 is a schematic diagram of RH vacuum refining in the examples of the present application;
FIG. 2 is a graph of the relationship between the N increase amount and the nitrogen blowing time in the embodiment of the present application.
Detailed Description
The following detailed description of embodiments of the present application is intended to be illustrative of the application and is not to be construed as limiting the application.
Referring to fig. 1, the RH vacuum refining method performs refining using an RH vacuum refining apparatus, wherein the RH vacuum refining apparatus includes: the steel ladle, the vacuum chamber and the two dip pipes, wherein one dip pipe is an ascending pipe, the other dip pipe is a descending pipe, the steel ladle is communicated with the vacuum chamber through the two dip pipes, a circulating gas blowing hole is formed in the position of the ascending pipe, circulating gas enters the ascending pipe through the blowing hole and drives molten steel to ascend from the ascending pipe to the vacuum chamber and descend to the steel ladle through the descending pipe to form circulation, and an alloy feeding bin is arranged at the top of the vacuum chamber and used for adding alloy into the molten steel and adjusting the components of the molten steel to target content.
The application mainly aims at the ultra-low carbon steel plates such as SPHC-B, LGW1000 and DC03 to carry out RH vacuum refining.
The embodiment of the application provides an RH vacuum refining method, wherein nitrogen and argon are sequentially adopted as circulating gas to guide molten steel to circularly flow for refining, wherein the time of taking nitrogen as the circulating gas can be set to be 1-7 min, and the nitrogen increasing amount of the molten steel is controlled to be below 7 ppm.
According to the embodiment of the application, nitrogen and argon are sequentially adopted as the circulating gas, on one hand, nitrogen is added as the circulating gas at the early stage, and the circulating time of the nitrogen is controlled, so that the nitrogen increasing amount of the molten steel is controlled; on the other hand, the nitrogen and the argon are sequentially used as the circulating gas, so that the production cost of using pure argon as the circulating gas can be reduced.
Preferably, the time period of the nitrogen as the circulating gas is 5-7 min.
As an example, the step of refining by guiding the molten steel to circularly flow by using nitrogen as the circulating gas may include:
nitrogen gas of 95-105 m3The flow rate is/h, so that the molten steel is circularly degassed between a steel ladle and the vacuum chamber for 3-4 min; in the initial circulation process, the carbon content in the molten steel is high, the decarburization reaction of carbon and oxygen is severe, and the flow speed of the initial nitrogen is set to be 95-105 m3The flow velocity is/h, the small flow provides circulation, the condition of molten steel explosive splashing generated in the rapid decarburization process can not occur, the carbon content can be removed to be less than 200ppm under the small flow circulation, and after most of the carbon content is removed, the circulation flow is improved, and the explosive splashing can not be generated.
The flow rate of the nitrogen is increased to 185-195 m3And h, continuously circularly flowing and degassing the molten steel between the steel ladle and the vacuum chamber for 2-3 min. Under the condition of low carbon content, the flow rate of the circulating gas is increased, the circulating speed can be increased, and molten steel can not be splashed explosively.
Specifically, when the carbon content in the molten steel is higher or the oxygen content is lower, top lance oxygen blowing can be carried out in the RH vacuum refining process, and the flow of nitrogen in the oxygen blowing process of the top lance can be adjusted to 170-180 m3H, adjusting the flow rate of the nitrogen to 185-195 m after oxygen blowing3H is used as the reference value. In the oxygen blowing process, because the vacuum degree can be improved, nitrogen is easily increased, the flow of nitrogen is reduced, the nitrogen increasing amount can be reduced, the original flow value is recovered after oxygen blowing is finished, the large flow is circularly refined, and the refining efficiency is improved.
Since the present application is primarily directed to RH vacuum refining of low carbon steel, reference is made to FIG. 2, which shows blowing for different times N2After smelting, the N content in the molten steel is relative to the N content change relation chart in the molten steel before RH treatment, and N is blown by circumfluence2The time is 0-7 min, the content of N in the molten steel does not exceed the requirement of steel grade, the content of N added in the molten steel is less than 7ppm, and various N blows2The N content of the molten steel is lower than 50ppm in time; due to the fact thatThis ensures the circulation blowing of N2The time is within 7min, such as 1-7 min, preferably 5-7 min, and the control requirement of the N content of the steel grade can be met.
As an example, the step of refining by using argon as circulating gas to guide the molten steel to circularly flow comprises the following steps:
the argon gas is 185-195 m3The molten steel is circularly degassed between a steel ladle and a vacuum chamber at the flow velocity of/h, the oxygen content at the decarburization end point is kept to be 300-600 ppm, aluminum is added for deoxidation alloying, and the flow of argon is adjusted to be 145-155 m3And/h, keeping the flow until the smelting is finished. The production cost in the later stage of circulation can be reduced by reducing the Ar circulation flow step by step, the quality of molten steel can be improved, and excessive inclusions are avoided.
Specifically, when the vacuum degree of the vacuum chamber is less than 133Pa, the argon gas is 185-195 m3And/h, circularly degassing the molten steel between a steel ladle and the vacuum chamber for 4-6 min at the flow velocity, and then adding aluminum.
Specifically, after adding aluminum, argon gas is used for heating at 145-155 m3The molten steel is circularly degassed between a steel ladle and a vacuum chamber for 4-6 min at the flow velocity of/h, the content of the components of the molten steel is adjusted to be the content of target components, and the argon gas is 145-155 m3And the flow rate per hour enables the molten steel to be circularly and purely degassed between a steel ladle and the vacuum chamber for 4-8 min until smelting is finished. The time interval between aluminum adding and subsequent alloy adding and the argon degassing time are kept, and the aim is to ensure that impurities are sufficiently floated and removed, so that the quality of molten steel meets the requirements. The final molten steel composition can be adjusted after the aluminum is added for deoxidation.
If argon and nitrogen are sequentially adopted as the circulating gas, and finally the nitrogen is adopted as the circulating gas to circulate until refining is finished, the nitrogen content in the molten steel is excessively increased. Therefore, in the embodiment of the application, nitrogen is firstly adopted and then argon is adopted as the circulating gas, so that the low nitrogen increment is controlled.
When RH vacuum smelting is carried out, the vacuum degree of a vacuum chamber needs to be adjusted, and the vacuum degree of the vacuum chamber is gradually reduced to be less than 133Pa from 30kPa to 50kPa, and the method specifically comprises the following steps:
starting smelting, starting a vacuum pump to pump for 5 stages for more than 1min until the vacuum degree is 25000Pa or less, starting a 4-stage pump to pump for more than 3min until the vacuum degree is 7500Pa or less, starting a 3-stage pump to pump for more than 3.5min until the vacuum degree is 2000Pa or less, starting a 2-stage pump to pump for more than 2min until the vacuum degree is 500Pa or less, and starting a 1-stage pump to pump for more than 1min until the vacuum degree is 133Pa or less. In the processing process, the vacuum pump is controlled to be started at the same time with the set time, if one condition is not met, the corresponding vacuum pump is not started, and the moment when the vacuum pump is started is the moment when the vacuum degree and the set time both reach the preset condition.
In the above embodiments, before the step of refining by guiding molten steel to circularly flow by sequentially using nitrogen and argon as circulating gas, the method further includes: and lifting the steel ladle to a position in the steel ladle, wherein the slag surface is 400-600 mm higher than the end part of the lower opening of the dip pipe. The height of the slag surface from the end part of the lower opening of the dip pipe is smaller, so that the steel slag can participate in circulation and the quality of molten steel is deteriorated; the larger height may cause a loss of the RH vacuum refining apparatus.
As a specific example of the application, the smelting steel is DC03, and the content of N in molten steel in an argon station of a converter is less than 40 ppm. Aiming at the molten steel, the RH vacuum refining method comprises the following steps:
s10, checking the tightness of the vacuum chamber, the dip pipe, the top lance and the hot bend pipe, avoiding air leakage in the refining process and ensuring that the vacuum degree can be reduced to below 133 pa;
s20, lifting the steel ladle filled with the molten steel at the treatment position to enable the slag surface of the steel ladle to be 400-600 mm higher than the end part of the lower opening of the dip pipe, ensuring that the vacuum chamber is in a closed state and the dip pipe is positioned in the molten steel, and continuously lifting the molten steel into the vacuum chamber without generating slag suction;
s30, pre-vacuumizing to make the pressure in the vacuum chamber between 30kpa and 50 kpa.
Opening the main valve for formal smelting, and using circulating gas N2At a flow rate of 100m3The molten steel is circularly degassed between the steel ladle and the vacuum chamber;
s40, beginning smelting for 4min, increasing N2The circulation flow is 190m3H; oxygen blowing using a top lance, N2The circulation flow rate was adjusted to 175m3H, blowingAdjusting N after the oxygen is finished2The circulation flow is 190m3/h。
The change condition of the circulation flow is adjusted according to the time points, and the circulation starts to blow N from the starting main valve2And the blowing time is ensured to be 7min, and then the circulating gas is switched to Ar until the smelting is finished.
S50, calculating the ultimate vacuum time when the vacuum degree reaches below 133pa, keeping the ultimate vacuum time for 4-6 min, keeping the oxygen content at the decarburization end point at 30-600 ppm, adding aluminum for deoxidation alloying, and starting from the completion of adding aluminum, wherein the Ar circulation flow is 190m3The h is adjusted to 150m3And h, keeping for 4-6 min after adding aluminum, adding other alloys to adjust the content of the molten steel components to be target components, pure degassing for 4-8 min, and finishing smelting.
Starting RH vacuum smelting, starting a main valve, regulating the vacuum degree of a vacuum chamber, gradually reducing the vacuum degree of the vacuum chamber from 30kPa to 50kPa to below 133Pa, and degassing molten steel between a steel ladle and the vacuum chamber.
On one hand, the ultimate vacuum time is kept, so that the C content in the molten steel can be guaranteed to be removed to the target requirement of ultra-low carbon, the end-point oxygen content is guaranteed, the molten steel quality is improved, and excessive inclusions are avoided. The reduction of the Ar circulation flow can reduce the production cost in the later circulation stage and can improve the quality of the molten steel.
Tests show that N is blown in the early stage of circulation2The contents of inclusions in the samples after the completion of the smelting are shown in Table 1 under the conditions of 6min of time and the later stage Ar blowing or the circulation full-process Ar blowing, and the circulation early stage N blowing can be found2The time is 6min, the size of the inclusions in the later stage Ar blowing or the circulation full-range Ar blowing is>5um, the content is 0.1-0.9 pieces/mm2Indicating circulating flow earlier stage blowing of N2Or the rule that the content of the impurities is not obviously influenced by blowing Ar in the whole process.
TABLE 1 relationship between blowing species at RH circulation early stage and molten steel inclusions
The embodiment of the application is to blow N2Time is 7min modeCalculation, average blow 1m3 N2Saving 2.5 yuan, saving cost by blowing 7min, first 4min and last 3min, 100/60 x 4 x 2.5+190/60 x (7-4) x 2.5-40.42 yuan. The method has the advantages that the cost can be saved by 48.5 yuan when one furnace of molten steel is smelted, the content of increased N is less, and the quality of the molten steel is not influenced.
Therefore, the embodiment of the application can reduce the production cost on the one hand, does not influence the molten steel quality on the other hand, and can control the nitrogen increasing amount on the other hand.
The above description is only a preferred embodiment of the present application and should not be taken as limiting the present application, and any modifications, equivalents and improvements made within the spirit and principle of the present application should be included in the protection scope of the present application.
Claims (8)
1. The RH vacuum refining method is characterized in that nitrogen and argon are sequentially adopted as circulating gas to guide molten steel to circularly flow for refining, wherein the time of taking the nitrogen as the circulating gas is 1-7 min, and the nitrogen increasing amount of the molten steel is controlled to be below 7 ppm.
2. The RH vacuum refining method according to claim 1, wherein the nitrogen gas is used as the circulating gas for a period of 5 to 7 min.
3. The RH vacuum refining method as set forth in claim 1, wherein the step of refining by guiding the circular flow of molten steel using nitrogen as a circulating gas comprises:
the nitrogen gas is 95-105 m3Guiding the molten steel to circularly flow at the flow speed/h for degassing for 3-4 min;
the flow rate of the nitrogen is increased to 185-195 m3And h, continuously guiding the molten steel to circularly flow and degas for 2-3 min.
4. The RH vacuum refining method of claim 3, wherein the step of increasing the flow rate of nitrogen further comprises: when top lance oxygen blowing is carried out in the vacuum chamber, the flow of nitrogen in the process of top lance oxygen blowing is adjusted to 170-180 m3/h，After the oxygen blowing is finished, the flow velocity of the nitrogen is adjusted to 185-195 m3/h。
5. The RH vacuum refining method as claimed in claim 1, wherein the step of refining by guiding the circular flow of molten steel using argon as a circulating gas comprises:
the argon gas is 185-195 m3The molten steel is subjected to circular flow degassing between a steel ladle and a vacuum chamber for 4-6 min at the flow velocity of/h, the oxygen content at the decarburization end point is kept at 300-600 ppm, aluminum is added for deoxidation alloying, and the flow of argon is adjusted to 145-155 m3And h until the smelting is finished.
6. The RH vacuum refining method of claim 5, wherein the argon gas is supplied at 145-155 m after the aluminum is added3Guiding the molten steel to circularly flow and degas for 4-6 min at a flow speed of/h, adjusting the content of other components of the molten steel to the content of target components, and using argon gas at 145-155 m3And guiding the molten steel to circularly flow and degas for 4-8 min at the flow rate/h until the smelting is finished.
7. The RH vacuum refining method of claim 1, further comprising:
starting a main valve for smelting, starting 5-stage pumping by a vacuum pump for more than 1min until the vacuum degree is 25000Pa or less, starting 4-stage pumping for more than 3min until the vacuum degree is 7500Pa or less, starting 3-stage pumping for more than 3.5min until the vacuum degree is 2000Pa or less, starting 2-stage pumping for more than 2min until the vacuum degree is 500Pa or less, and starting 1-stage pumping for more than 1min until the vacuum degree is 133Pa or less.
8. The RH vacuum refining method as claimed in claim 1, wherein before the step of refining by guiding the molten steel to circulate by using nitrogen and argon as circulating gas in sequence, the method further comprises:
the tightness of the RH vacuum refining device is checked, the air leakage condition in the RH vacuum refining process is avoided, and the vacuum degree can be guaranteed to be below 133 pa;
and lifting the steel ladle to a position in the steel ladle, wherein the slag surface is 400-600 mm higher than the end part of the lower opening of the dip pipe.
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114959186A (en) * | 2022-06-10 | 2022-08-30 | 东北大学 | RH vacuum refining device and method with partition wall in ladle |
| CN115074491A (en) * | 2021-03-16 | 2022-09-20 | 上海梅山钢铁股份有限公司 | RH furnace circulation gas automatic control method |
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| CN110453029A (en) * | 2019-09-25 | 2019-11-15 | 敬业钢铁有限公司 | The method of the inexpensive accurate control siliceous low-alloy steel nitrogen content of high nitrogen |
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| CN115074491A (en) * | 2021-03-16 | 2022-09-20 | 上海梅山钢铁股份有限公司 | RH furnace circulation gas automatic control method |
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| CN114959186A (en) * | 2022-06-10 | 2022-08-30 | 东北大学 | RH vacuum refining device and method with partition wall in ladle |
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