CN114317865B - Method for controlling carbon-oxygen reaction of vacuum treatment of aluminum-free bearing steel - Google Patents
Method for controlling carbon-oxygen reaction of vacuum treatment of aluminum-free bearing steel Download PDFInfo
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- CN114317865B CN114317865B CN202210110423.3A CN202210110423A CN114317865B CN 114317865 B CN114317865 B CN 114317865B CN 202210110423 A CN202210110423 A CN 202210110423A CN 114317865 B CN114317865 B CN 114317865B
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 88
- 239000010959 steel Substances 0.000 title claims abstract description 88
- 238000000034 method Methods 0.000 title claims abstract description 30
- 238000009489 vacuum treatment Methods 0.000 title claims abstract description 26
- CSJDCSCTVDEHRN-UHFFFAOYSA-N methane;molecular oxygen Chemical compound C.O=O CSJDCSCTVDEHRN-UHFFFAOYSA-N 0.000 title claims abstract description 20
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims abstract description 41
- 229910052760 oxygen Inorganic materials 0.000 claims abstract description 41
- 239000001301 oxygen Substances 0.000 claims abstract description 41
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 29
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 26
- 239000002893 slag Substances 0.000 claims abstract description 23
- 238000010079 rubber tapping Methods 0.000 claims abstract description 20
- 238000007670 refining Methods 0.000 claims abstract description 19
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 claims abstract description 9
- 229910010271 silicon carbide Inorganic materials 0.000 claims abstract description 9
- 238000003723 Smelting Methods 0.000 claims abstract description 8
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 14
- 229910052782 aluminium Inorganic materials 0.000 claims description 14
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 11
- 229910052742 iron Inorganic materials 0.000 claims description 7
- 229910052710 silicon Inorganic materials 0.000 claims description 7
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 6
- 239000010936 titanium Substances 0.000 claims description 6
- 229910052719 titanium Inorganic materials 0.000 claims description 6
- 229910052717 sulfur Inorganic materials 0.000 claims description 3
- 238000004886 process control Methods 0.000 claims description 2
- 239000002436 steel type Substances 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 abstract description 14
- 238000005272 metallurgy Methods 0.000 abstract description 2
- 238000005406 washing Methods 0.000 abstract description 2
- 239000006004 Quartz sand Substances 0.000 abstract 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 abstract 1
- 238000004140 cleaning Methods 0.000 abstract 1
- 230000002035 prolonged effect Effects 0.000 abstract 1
- 238000005728 strengthening Methods 0.000 abstract 1
- 239000000956 alloy Substances 0.000 description 5
- 229910045601 alloy Inorganic materials 0.000 description 5
- 238000009749 continuous casting Methods 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 230000002159 abnormal effect Effects 0.000 description 4
- 238000010438 heat treatment Methods 0.000 description 4
- 239000010703 silicon Substances 0.000 description 4
- 239000002699 waste material Substances 0.000 description 4
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 description 2
- 238000007664 blowing Methods 0.000 description 2
- 229910002091 carbon monoxide Inorganic materials 0.000 description 2
- 238000005266 casting Methods 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 238000005070 sampling Methods 0.000 description 2
- 230000009286 beneficial effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 239000011819 refractory material Substances 0.000 description 1
Classifications
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- 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
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- Treatment Of Steel In Its Molten State (AREA)
Abstract
The invention relates to the technical field of metallurgy, in particular to a method for controlling a carbon-oxygen reaction of aluminum-free bearing steel in vacuum treatment, which comprises the following specific steps: (1) The primary smelting process needs to control the end point oxygen content and the target carbon content, the tapping operation is enhanced, and a sliding plate is used for slag stopping during tapping; (2) ladle washing is carried out on the ladle; (3) refining: controlling the alkalinity of slag in the early stage of refining, and adding quartz sand in the late stage of refining to reduce the alkalinity of slag; (4) Strengthening LF refining slag surface deoxidation, carrying out deoxidation operation by using high-purity high-density silicon carbide, and controlling the oxygen content to be less than or equal to 15ppm before vacuum treatment; (5) Adopting a preliminary vacuum tank, and cleaning residual steel residues in a vacuum chamber before production; (6) The vacuum treatment time is prolonged, the vacuum degree is improved to less than 67pa, the pressure is maintained under high vacuum, the oxygen content in the bearing steel production process can be reduced, the carbon-oxygen reaction balance can be maintained, the stability of a vacuum chamber is improved, and the occurrence of unexpected production accidents is reduced.
Description
Technical Field
The invention relates to the technical field of metallurgy, in particular to a method for controlling a carbon-oxygen reaction of aluminum-free bearing steel in vacuum treatment.
Background
The aluminum-free bearing steel is characterized in that the aluminum content of molten steel is controlled to be less than or equal to 15ppm, and the aluminum content of the used alloy auxiliary materials and the aluminum content of the refractory materials contacted with the molten steel are strictly controlled, so that the inclusions are low-melting-point shaped inclusions, the castability of the molten steel is strong, and the influence of the inclusions on the fatigue life of the steel is lower than that of the high-melting-point non-deforming inclusions. However, in the production process, the carbon-oxygen reaction is severe in the vacuum treatment process due to the high carbon content of molten steel, the molten steel is splashed to the upper tank and the top lance, the carbon monoxide concentration is continuously high, the carbon content and the oxygen content of the molten steel exceed the process requirements, and secondary treatment is forced to be carried out, so that the continuous casting machine can stop casting. Therefore, the carbon-oxygen reaction in the vacuum treatment process must be controlled to ensure that the carbon and oxygen components meet the technological requirements of the aluminum-free bearing steel.
Disclosure of Invention
The invention aims to solve the technical problems that: in order to solve the problems that in the prior art, the carbon-oxygen reaction is severe in the vacuum treatment process due to high carbon content of molten steel, the molten steel is splashed to an upper tank and a top gun, the concentration of carbon monoxide is continuously high, the carbon content and the oxygen content of the molten steel exceed the process requirements, secondary treatment is forced, and the continuous casting machine is likely to stop production due to the fact that the casting machine is in a broken state, the method for controlling the carbon-oxygen reaction in the vacuum treatment of the aluminum-free bearing steel is provided.
The technical scheme adopted for solving the technical problems is as follows: the method for controlling the carbon-oxygen reaction of the aluminum-free bearing steel in the vacuum treatment is characterized by comprising the following specific steps:
(1) The primary smelting process needs to control the end point oxygen content and the target carbon content, the tapping operation is enhanced, and a sliding plate is used for slag stopping during tapping;
(2) The steel ladle is washed, and steel grades containing harmful elements such as high oxygen, aluminum, titanium and the like cannot be smelted in the early stage of the steel ladle;
(3) The LF process adopts low-alkalinity refining slag, and high-purity silicon carbide (SiC is more than or equal to 90 percent) is used for carrying out slag surface deoxidation;
(4) After refining, the Si content of the molten steel is increased to 0.30-0.35 percent so as to ensure that the dissolved oxygen of the molten steel is controlled within 15ppm;
(5) RH adopts a preliminary vacuum tank, and the RH high vacuum (67 Pa) time is 25-30 min to control the total oxygen content of the molten steel.
The bearing steel further comprises the following components: 0.95 to 1.05 percent of C, 0.30 to 0.35 percent of Si, 0.25 to 0.40 percent of Mn, 0.020 percent of P, 0.015 percent of S, 0.0015 percent of Al, 1.40 to 1.60 percent of Cr and the balance of iron and residual elements.
Further comprising the step (1) of controlling the carbon content of the final molten steel to be more than 0.15% so as to reduce the tapping oxygen content to be less than 200 ppm.
Further comprises the step (3) of controlling the alkalinity of the refining slag in the LF refining process to be 0.80-1.20.
Further included is that after the RH vacuum tank is used for more than 50 furnaces, the RH vacuum tank is no longer used for producing aluminum-free bearing steel.
The beneficial effects of the invention are as follows: the method for controlling the carbon-oxygen reaction in the vacuum treatment of the aluminum-free bearing steel provided by the invention reduces the tapping oxygen content by controlling the carbon content of the endpoint, controls the slag alkalinity to control the slag oxygen content and controls the high vacuum pressure maintaining time,
1. the quality accident caused by high oxygen content of aluminum-free bearing steel in the production process is solved, and the oxygen content in the bearing steel production process can be reduced;
2. the problem that the components are abnormal due to the fact that carbon-oxygen reaction is easy to occur in the vacuum process under the condition of low aluminum content of aluminum-free bearing steel is solved, and carbon-oxygen reaction balance can be maintained;
3. the problem of serious shaking of the vacuum chamber in the vacuum process under the condition of low aluminum content of the aluminum-free bearing steel is solved, and the stability of the vacuum chamber is improved;
4. solves the problem that the accident of production interruption is likely to happen, and reduces the occurrence of the accident of production.
Detailed Description
The method for controlling the carbon-oxygen reaction of the aluminum-free bearing steel in the vacuum treatment is characterized by comprising the following specific steps:
(1) The primary smelting process needs to control the end point oxygen content and the target carbon content, the tapping operation is enhanced, and a sliding plate is used for slag stopping during tapping;
(2) The steel ladle is washed, and steel grades containing harmful elements such as high oxygen, aluminum, titanium and the like cannot be smelted in the early stage of the steel ladle;
(3) The LF process adopts low-alkalinity refining slag, and high-purity silicon carbide (SiC is more than or equal to 90 percent) is used for carrying out slag surface deoxidation;
(4) After refining, the Si content of the molten steel is increased to 0.30-0.35 percent so as to ensure that the dissolved oxygen of the molten steel is controlled within 15ppm;
(5) RH adopts a preliminary vacuum tank, and the RH high vacuum (67 Pa) time is 25-30 min to control the total oxygen content of molten steel, so as to ensure that the purity of the molten steel meets the requirements of bearing steel.
The bearing steel comprises the following components: 0.95 to 1.05 percent of C, 0.30 to 0.35 percent of Si, 0.25 to 0.40 percent of Mn, 0.020 percent of P, 0.015 percent of S, 0.0015 percent of Al, 1.40 to 1.60 percent of Cr and the balance of iron and residual elements.
In the step (1), the carbon content of the final molten steel is more than 0.15%, and the tapping oxygen content is controlled to be lower than 200 ppm.
In the step (3), the LF refining process controls the alkalinity of refining slag to be 0.80-1.20 so as to solve the problem of the pourability of bearing steel molten steel.
When the RH vacuum tank is used for more than 50 furnaces, the RH vacuum tank is not used for producing aluminum-free bearing steel.
The oxygen content of the aluminum-free bearing steel produced by the method can be controlled to be 5-10 ppm, the average value of total oxygen is 6.5ppm, and the production of over ten thousand tons of aluminum-free bearing steel does not cause abnormal components and production interruption accidents due to severe carbon-oxygen reaction.
The present invention will be described in detail with reference to examples, but the present invention is not limited to these examples.
Example 1:
(1) Decarburizing, dephosphorizing, preserving carbon, heating and tapping after the waste steel and the desulfurized molten iron are subjected to primary smelting furnace, wherein the target carbon content is controlled to be 0.16%, and the tapping oxygen content is 180ppm;
(2) The steel ladle is washed, and the steel grade produced in the early stage of the steel ladle is a hard wire steel grade with non-high oxygen, low aluminum and low titanium;
(3) The alkalinity of slag in the earlier stage of refining is 1.8, the content of alloy silicon element is controlled to be 0.30%, and the oxygen content of molten steel before vacuum treatment is 14ppm;
(4) Adopting a front-stage vacuum tank, and carrying out line feeding for the 8 th time;
(5) The vacuum treatment time is 28min; after the air is broken, soft blowing is carried out until continuous casting is carried out;
the bearing steel produced by the method is cast for 17 furnaces, and the phenomena of abnormal components and production interruption caused by carbon-oxygen reaction do not occur.
Example 2:
1) Decarburizing, dephosphorizing, preserving carbon, heating and tapping after the waste steel and the desulfurized molten iron are subjected to primary smelting furnace, wherein the target carbon content is controlled to be 0.18%, and the tapping oxygen content is 160ppm;
(2) The steel ladle is washed, and the steel grade produced in the early stage of the steel ladle is a hard wire steel grade with non-high oxygen, low aluminum and low titanium;
(3) The alkalinity of slag in the earlier stage of refining is 1.9, the content of alloy silicon element is controlled to be 0.31%, and the oxygen content of molten steel before vacuum treatment is 14ppm;
(4) Adopting a front-stage vacuum tank, and carrying out 23 times of online;
(5) Vacuum treatment time is 30min; and after the air is broken, soft blowing is carried out until continuous casting is carried out.
The bearing steel produced by the method is 15 furnaces after being poured for the whole time, and the phenomena of abnormal components and production interruption caused by carbon-oxygen reaction do not occur.
Comparative example 1:
(1) Decarburizing, dephosphorizing, preserving carbon, heating and tapping the waste steel and the desulfurized molten iron in a primary smelting furnace, wherein the target carbon content is controlled to be 0.08%, and the tapping oxygen content is 459ppm;
(2) Washing the hard wire steel ladle;
(3) The silicon element component of the alloy is normally controlled to be 0.22 percent, high-purity silicon carbide is used for deoxidization, and the oxygen content of molten steel before vacuum treatment is 22ppm;
(4) Adopting a front-stage vacuum tank, and feeding the wire for the 6 th time;
(5) The vacuum treatment time is 29min; C-O reaction is severe in the vacuum treatment process, meanwhile, the vacuum tank shakes seriously, the C content of molten steel after vacuum is 0.88%, 1200m carbon wires are forced to be fed to adjust the C content, and continuous casting is carried out.
Comparative example 2:
(1) Decarburizing, dephosphorizing, preserving carbon, heating and tapping after the waste steel and the desulfurized molten iron are subjected to primary smelting furnace, wherein the target carbon content is controlled to be 0.15%, and the tapping oxygen content is 200ppm;
(2) The steel ladle is washed, and the steel grade produced in the early stage of the steel ladle is a hard wire steel grade with non-high oxygen, low aluminum and low titanium;
(3) The alkalinity of slag in the earlier stage of refining is 1.9, the silicon element content of alloy is controlled to be 0.30%, and the oxygen content of molten steel before vacuum treatment is 15ppm;
(4) Adopting a later-stage vacuum tank, feeding the steel wire for 70 times, and leaving part of slag steel in the vacuum chamber;
(5) The vacuum treatment time is 25min; sampling and oxygen determination are carried out after the air break.
The carbon reaction in the slag steel and the molten steel in the vacuum chamber is severe, so that the concentration of the tail gas detected CO is more than 95%, the severe carbon-oxygen reaction in the early stage of the vacuum treatment is large in shaking of the vacuum chamber, high vacuum pressure maintaining cannot be carried out until the carbon-oxygen reaction is finished after 10min, the sampling carbon content after the vacuum treatment is finished is 0.85%, the requirement of the carbon content is lower than 0.95% of the steel grade, the oxygen content of the molten steel is higher than 15ppm, and the secondary treatment of re-deoxidation is needed to influence the smooth production.
With the above-described preferred embodiments according to the present invention as an illustration, the above-described descriptions can be used by persons skilled in the relevant art to make various changes and modifications without departing from the scope of the technical idea of the present invention. The technical scope of the present invention is not limited to the description, but must be determined according to the scope of claims.
Claims (2)
1. The method for controlling the carbon-oxygen reaction of the aluminum-free bearing steel in the vacuum treatment is characterized by comprising the following specific steps:
(1) The initial smelting process needs to control the final oxygen content and the target carbon content, the tapping operation is enhanced, the tapping uses a sliding plate to stop slag, the carbon content of the final molten steel is controlled to be more than 0.15%, and the tapping oxygen content is further reduced to be less than 200ppm;
(2) The ladle is washed, and steel types containing harmful elements of high oxygen, aluminum and titanium cannot be smelted in the early stage of the ladle;
(3) The LF process adopts low-alkalinity refining slag, the LF refining process controls the alkalinity of the refining slag to be 0.80-1.20, high-purity silicon carbide is used for slag surface deoxidation, and the SiC content in the high-purity silicon carbide is more than or equal to 90%;
(4) After refining, the Si content of the molten steel is increased to 0.30-0.35 percent so as to ensure that the dissolved oxygen of the molten steel is controlled within 15ppm;
(5) RH adopts a preliminary vacuum tank, RH high vacuum is less than 67Pa, and RH high vacuum time is 25-30 min to control the total oxygen content of molten steel;
the bearing steel comprises the following components: 0.95 to 1.05 percent of C, 0.30 to 0.35 percent of Si, 0.25 to 0.40 percent of Mn, 0.020 percent of P, 0.015 percent of S, 0.0015 percent of Al, 1.40 to 1.60 percent of Cr and the balance of iron and residual elements.
2. The method for controlling the reaction of carbon and oxygen in vacuum treatment of aluminum-free bearing steel according to claim 1, wherein the method comprises the following steps: when the RH vacuum tank is used for more than 50 furnaces, the RH vacuum tank is not used for producing aluminum-free bearing steel.
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| CN104212935B (en) * | 2014-08-22 | 2016-03-16 | 山东西王特钢有限公司 | A kind of method with high titanium ferrochrome production high-quality GCr15 bearing steel |
| CN105463150B (en) * | 2015-12-18 | 2017-05-31 | 中天钢铁集团有限公司 | A kind of automobile hub bearing steel smelting technique |
| CN109252013A (en) * | 2018-09-28 | 2019-01-22 | 中天钢铁集团有限公司 | A kind of bearing steel slagging process control method of full plastic occluded foreignsubstance |
| CN109055664A (en) * | 2018-10-08 | 2018-12-21 | 中天钢铁集团有限公司 | A kind of bearing steel molten steel deoxidation control method of no Ds type impurity |
| CN109402327B (en) * | 2018-11-22 | 2020-09-01 | 江阴兴澄特种钢铁有限公司 | External refining production method of ultrapure high-carbon chromium bearing steel |
| CN110846581B (en) * | 2019-12-05 | 2021-01-29 | 中天钢铁集团有限公司 | Smelting method for realizing ultrahigh purity of bearing steel by controlling alkalinity of furnace slag and combining electromagnetic stirring of tundish |
| CN110983161B (en) * | 2019-12-05 | 2021-03-23 | 中天钢铁集团有限公司 | Smelting method for realizing ultrahigh purity of bearing steel by controlling adding time of low-aluminum low-titanium ferrosilicon and combining with tundish electromagnetic stirring |
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