CN116064998A - RH refining treatment process of Q235NH weathering steel - Google Patents
RH refining treatment process of Q235NH weathering steel Download PDFInfo
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- CN116064998A CN116064998A CN202310044050.9A CN202310044050A CN116064998A CN 116064998 A CN116064998 A CN 116064998A CN 202310044050 A CN202310044050 A CN 202310044050A CN 116064998 A CN116064998 A CN 116064998A
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- Prior art keywords
- treatment
- steel
- refining
- q235nh
- controlling
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- 238000000034 method Methods 0.000 title claims abstract description 35
- 238000007670 refining Methods 0.000 title claims abstract description 28
- 229910000870 Weathering steel Inorganic materials 0.000 title description 5
- 229910000831 Steel Inorganic materials 0.000 claims abstract description 51
- 239000010959 steel Substances 0.000 claims abstract description 51
- 238000007872 degassing Methods 0.000 claims abstract description 9
- 229910045601 alloy Inorganic materials 0.000 claims abstract description 8
- 239000000956 alloy Substances 0.000 claims abstract description 8
- 238000007664 blowing Methods 0.000 claims abstract description 6
- 238000012840 feeding operation Methods 0.000 claims abstract description 5
- 229910001069 Ti alloy Inorganic materials 0.000 claims abstract description 4
- 238000003723 Smelting Methods 0.000 abstract description 4
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 24
- 229910052757 nitrogen Inorganic materials 0.000 description 12
- OYPRJOBELJOOCE-UHFFFAOYSA-N Calcium Chemical compound [Ca] OYPRJOBELJOOCE-UHFFFAOYSA-N 0.000 description 9
- 229910052791 calcium Inorganic materials 0.000 description 9
- 239000011575 calcium Substances 0.000 description 9
- 238000009489 vacuum treatment Methods 0.000 description 5
- 238000005516 engineering process Methods 0.000 description 4
- 238000004519 manufacturing process Methods 0.000 description 4
- 230000008901 benefit Effects 0.000 description 3
- 238000009749 continuous casting Methods 0.000 description 3
- 238000009628 steelmaking Methods 0.000 description 3
- 238000003466 welding Methods 0.000 description 3
- 230000003749 cleanliness Effects 0.000 description 2
- 230000018109 developmental process Effects 0.000 description 2
- 239000012535 impurity Substances 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 239000002893 slag Substances 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- 229910001295 No alloy Inorganic materials 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 238000005261 decarburization Methods 0.000 description 1
- 238000004925 denaturation Methods 0.000 description 1
- 230000036425 denaturation Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 238000005065 mining Methods 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000002035 prolonged effect Effects 0.000 description 1
- 238000003908 quality control method Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000010079 rubber tapping Methods 0.000 description 1
- 238000005496 tempering Methods 0.000 description 1
Classifications
-
- 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
-
- 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
- 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 invention discloses an RH refining treatment process of Q235NH weather resistant steel, which comprises the steps of controlling the components of the Q235NH steel in an internal control range in an LF refining process, feeding wires for 200-300 m/furnace after the LF refining process is finished, controlling the end temperature of molten steel at 1605-1615 ℃, adding no or little alloy except titanium alloy in the RH refining furnace treatment process after 3min of RH treatment, controlling the adding amount within 50Kg, controlling the RH degassing time at 15-18min, controlling the pure degassing time within the whole treatment time to be more than or equal to 10min, fully playing the RH inclusion treatment capability, and stopping the wire feeding operation and the soft blowing operation after the RH treatment. Under the condition of ensuring the internal quality of steel, the wire feeding and soft blowing operation time can be reduced, the smelting treatment period of RH is shortened by 5-10 min, and the RH operation efficiency is effectively improved.
Description
Technical Field
The invention relates to an RH refining treatment process of Q235NH weathering steel.
Background
RH refining is commonly referred to as RH vacuum cycle degassing refining. With the development and development of vacuum steelmaking technology, the RH refining furnace has the advantages of short treatment time, low cost, capability of treating a large amount of molten steel and the like because of adopting the technology of circulating molten steel in a vacuum tank, and can be matched with converter continuous casting.
Q235NH is a weather-resistant steel grade, and has high strength, and particularly has higher comprehensive mechanical properties in a normalizing or normalizing plus tempering state. The welding structure is mainly used for large ships, bridges, power station equipment, medium-pressure and high-pressure boilers, high-pressure containers, rolling stock, hoisting machinery, mining machinery and other large welding structures.
The nitrogen content in the steel has direct influence on the performance of steel materials, and the exceeding nitrogen content can reduce the formability, welding performance, toughness and plasticity of the steel, and aggravate the aging and cold embrittlement of the steel. The requirements of modern industry on purity of steel are increasing. In order to control the nitrogen content in the steel, the steel must be grasped from the source, and the increase of the nitrogen content is strictly controlled in the steelmaking process. Particularly, in the weather-resistant steel Q235NH, the lower the required nitrogen content is, the better the required nitrogen content is, however, nitrogen is increased in the wire feeding process of the actual molten steel; the inclusion control is a steel smelting process, the effective control is required, and the fewer and the better the inclusion in the steel, but the slag and alloy are required to be added and the wire feeding calcium treatment is required in the actual smelting process, and the materials pollute the molten steel.
In order to promote the denaturation of steel impurities to be easily removed, reduce the impurity level and improve the service performance of steel, an RH refining furnace of a steel mill of a steel enterprise is used for carrying out a calcium treatment process after the vacuum treatment of molten steel is finished, but according to the actual production condition of the RH refining furnace, the following adverse factors are caused by adopting the calcium treatment process:
the requirement on the initial temperature is high, and according to statistics, the temperature of molten steel is reduced by 8-15 ℃ in the RH calcium treatment process, so that in order to ensure that the terminal temperature meets the requirement, the LF refining furnace needs to increase the tapping temperature and the power consumption;
2. the nitrogen increase of molten steel can be caused, and as the steel slag is splashed greatly when the RH refining furnace carries out wire feeding calcium treatment, the nitrogen is absorbed by the molten steel from the air, and according to statistics, the nitrogen increase is 7-11 ppm when the wire feeding amount is 200-300 m;
3. the production is smooth, the RH average vacuum treatment time is 20.6min, the calcium treatment is carried out, the inclusion in the steel is removed by at least soft blowing for 8min after the calcium treatment, the inclusion content in the steel can be increased due to improper wire feeding, the quality control is not facilitated, meanwhile, the RH treatment period is prolonged, and the production is smooth.
Disclosure of Invention
The invention aims to provide an RH refining treatment process of Q235NH weathering steel, which can reduce wire feeding and soft blowing operation time, shorten RH smelting treatment period by 5-10 min and effectively improve RH operation efficiency under the condition of ensuring the internal quality of the steel.
The technical scheme adopted by the invention is that the RH refining treatment process of the Q235NH weathering steel comprises the steps that in the LF refining process, the components of the Q235NH steel are controlled within an internal control range, the end point temperature of molten steel is controlled to be 1605-1615 ℃ by 200-300 m/furnace after the LF refining treatment is finished, other alloys are not added or less added except titanium alloy is added after the RH treatment is carried out for 3min in the RH refining furnace treatment process, the addition amount is controlled to be within 50Kg, the RH degassing time is 15-18min, the pure degassing time is more than or equal to 10min in the whole treatment time, the RH inclusion treatment capability is fully exerted, and the RH treatment is finished without wire feeding operation and soft blowing operation.
Search document: by comparing the invention with the papers and the inventions, the invention is greatly different from the methods of improving the carbon temperature double hit rate of a converter, covering the whole process of a ladle, optimizing the decarburization process, changing the silicon steel feeding mode, optimizing the acid-soluble aluminum adding formula and the like, the invention focuses on advancing the wire feeding calcium treatment process, does not carry out wire feeding treatment in the RH refining treatment process, and achieves the purposes of reducing the RH treatment time and improving the productivity.
Before RH vacuum treatment, molten steel is subjected to LF treatment, steel-grade molten steel components are controlled according to a standard target value, so that alloy addition amount in the RH vacuum treatment is reduced, RH inclusion treatment capacity is fully exerted, meanwhile, wire feeding operation is finished after LF refining treatment, wire feeding operation is not performed after RH treatment, secondary oxidation of molten steel in the wire feeding process is avoided, and treatment time is controlled to be 15-18min in the RH treatment process.
The method is suitable for steel-making enterprises of the same type, after the method is used, the RH average treatment time is 16.3min, compared with the prior art, the RH treatment is reduced by 4.3min, the calcium treatment is not carried out after the RH treatment, the nitrogen increasing problem of molten steel in the wire feeding process is avoided, no alloy or little alloy is added in the RH treatment process, so that molten steel inclusions are always removed in the RH vacuum treatment process, the molten steel cannot be polluted because the RH treatment is not carried out after the RH treatment is finished, the cleanliness of the molten steel is ensured, the inclusion analysis is carried out from the steel, the inclusion level A, B, C and D is less than or equal to 1.5, the continuous casting pouring process cannot cause the cutoff of a continuous casting nozzle due to the inclusion problem in the steel, the method can be suitable for the production requirements of similar steel factories, and has obvious economic benefit and environmental benefit, and has higher practical value and popularization significance.
The application of the technology can improve RH operation efficiency, inhibit the effective control of nitrogen and inclusions in molten steel, and integrally improve the cleanliness of the steel, so that the technology has an optimistic application prospect.
Description of the embodiments
The RH refining process of Q235NH weather resistant steel includes LF refining with Q235NH steel in controlled temperature range of 200-300 m/furnace, molten steel end temperature of 1605-1615 deg.c, adding other alloy in the RH refining furnace except titanium alloy after RH treatment for 3min, adding alloy in 50Kg, RH degassing in 15-18min, pure degassing time over 10min, RH inclusion treating capacity, and RH treatment.
Claims (1)
1. The RH refining treatment process of Q235NH weather resistant steel is characterized in that in the LF refining process, the components of Q235NH steel are controlled within an internal control range, the end temperature of molten steel is controlled to be 1605-1615 ℃ at 200-300 m/furnace after the LF refining treatment, other alloys are not added or less added except titanium alloy after the RH treatment for 3min in the RH refining furnace treatment process, the addition amount is controlled to be within 50Kg, the RH degassing time is 15-18min, the pure degassing time is more than or equal to 10min in the whole treatment time, the RH inclusion treatment capability is fully exerted, and the wire feeding operation and the soft blowing operation are not carried out after the RH treatment is finished.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310044050.9A CN116064998A (en) | 2023-01-29 | 2023-01-29 | RH refining treatment process of Q235NH weathering steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202310044050.9A CN116064998A (en) | 2023-01-29 | 2023-01-29 | RH refining treatment process of Q235NH weathering steel |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN116064998A true CN116064998A (en) | 2023-05-05 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202310044050.9A Pending CN116064998A (en) | 2023-01-29 | 2023-01-29 | RH refining treatment process of Q235NH weathering steel |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN116064998A (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107699654A (en) * | 2017-09-25 | 2018-02-16 | 南京钢铁股份有限公司 | A kind of smelting process of ultra-low-carbon steel desulfurization rapidly |
| CN110760643A (en) * | 2019-11-29 | 2020-02-07 | 新疆八一钢铁股份有限公司 | RH smelting method of high-construction steel Q390GJEZ15 steel grade |
| KR20200075651A (en) * | 2018-12-18 | 2020-06-26 | 주식회사 포스코 | Refining method of high-purity molten steel |
| CN112430709A (en) * | 2020-11-20 | 2021-03-02 | 新疆八一钢铁股份有限公司 | Smelting method for cleaning high-construction steel refining molten steel |
| CN114540582A (en) * | 2022-03-20 | 2022-05-27 | 新疆八一钢铁股份有限公司 | Process for reducing smelting time of weathering steel grade Q55D by RH refining furnace |
-
2023
- 2023-01-29 CN CN202310044050.9A patent/CN116064998A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107699654A (en) * | 2017-09-25 | 2018-02-16 | 南京钢铁股份有限公司 | A kind of smelting process of ultra-low-carbon steel desulfurization rapidly |
| KR20200075651A (en) * | 2018-12-18 | 2020-06-26 | 주식회사 포스코 | Refining method of high-purity molten steel |
| CN110760643A (en) * | 2019-11-29 | 2020-02-07 | 新疆八一钢铁股份有限公司 | RH smelting method of high-construction steel Q390GJEZ15 steel grade |
| CN112430709A (en) * | 2020-11-20 | 2021-03-02 | 新疆八一钢铁股份有限公司 | Smelting method for cleaning high-construction steel refining molten steel |
| CN114540582A (en) * | 2022-03-20 | 2022-05-27 | 新疆八一钢铁股份有限公司 | Process for reducing smelting time of weathering steel grade Q55D by RH refining furnace |
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Application publication date: 20230505 |