CN114990309A - Novel bar oxygen quenching technology application process - Google Patents
Novel bar oxygen quenching technology application process Download PDFInfo
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- CN114990309A CN114990309A CN202210465718.2A CN202210465718A CN114990309A CN 114990309 A CN114990309 A CN 114990309A CN 202210465718 A CN202210465718 A CN 202210465718A CN 114990309 A CN114990309 A CN 114990309A
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- cooling water
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D9/00—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor
- C21D9/0075—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for rods of limited length
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- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
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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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- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatments In General, Especially Conveying And Cooling (AREA)
Abstract
The invention relates to the technical field of steel rolling in the metallurgical industry, in particular to a bar oxygen quenching novel technology application process, which comprises the steps of conveying a bar conveyed out of a K1 finished product rolling mill to an oxygen enrichment channel area for oxygen quenching, providing oxygen input inside the oxygen enrichment channel area, and quickly forming an oxide film on the surface of the bar; carrying out multistage sectional cooling temperature control of medium water pressure and low water content on the bar after the oxygen quenching is finished through a sectional multistage cooling control channel area; compared with the prior art, the method has the advantages that the oxygen quenching process is additionally arranged between the K1 finished product process and the multistage controlled cooling process, so that an oxide film can be quickly formed on the surface of the bar, the thickness of the primary film on the surface of the bar can be effectively increased in an oxygen-enriched environment, the red rust condition can be effectively reduced, the temperature interval of the red rust is compressed, the temperature of an upper cooling bed can be effectively reduced on the premise of solving the red rust, the proportion content of alloy manganese and manganese required by bar production is reduced, the production cost is reduced, and the profit space is improved.
Description
Technical Field
The invention relates to the technical field of steel rolling in the metallurgical industry, in particular to a novel bar oxygen quenching technology application process.
Background
From 11 months and 1 day in 2018, domestic construction steel manufacturers begin to implement new national standards for hot-rolled ribbed steel bars (deformed steel bars) (GB/T1499.2-2018). In the new standard, the specification of metallographic structure inspection, cross section Vickers hardness, macroscopic metallographic structure, microscopic structure and inspection method thereof are added, corresponding adjustment is made on the aspects of strength grade, size weight and allowable deviation, particularly 335 MPa-grade steel bars are cancelled, 600 MPa-grade steel bars and steel bar marks with 'E' are added, and 400, 500 and 600MPa strength series grades are formed.
After the new national standard is implemented, steel enterprises actively search for production process schemes meeting the conditions of the steel enterprises, but most of the enterprises mainly ensure the strength of the twisted steel by improving the content of Mn and V alloys, so that the production cost of the enterprises is directly increased. Meanwhile, the price of the domestic V alloy is increased, and the profit margin of the iron and steel enterprises is further compressed. Therefore, on the basis of a new national standard, a bar production line adopts a multi-section graded rolling control and cooling control technical means, so that the alloy addition is further reduced, green reduction production of replacing gold with water is realized, the production cost is reduced, and the profit margin is improved.
The bar production line has a plurality of problems in the technical means process of implementing multi-stage graded controlled rolling and controlled cooling, wherein the problem of red rust is particularly prominent, which not only seriously affects the appearance and the product image, but also is easier to be further corroded in the processes of storage, transportation and service, affects the use of customers and reduces the competitiveness of products of iron and steel enterprises.
At present, the scheme for solving red rust in the existing bar production line of iron and steel enterprises is as follows: the temperature of the upper cooling bed is increased, but obviously, the temperature of the upper cooling bed is increased in a way contrary to the controlled rolling concept, so that the controlled rolling and controlled cooling technical operation is not satisfactory in the production of the bar and is still at a middle and high level.
Disclosure of Invention
The invention aims to provide a novel technology application process for bar oxygen quenching, which can effectively reduce the temperature of an upper cooling bed under the condition of avoiding red rust of bars, thereby preventing the increase of Mn consumption, conforming to the rolling control concept and reducing the production cost so as to solve the problems in the background technology.
In order to achieve the purpose, the invention provides the following technical scheme: a process for applying a novel bar oxygen quenching technology comprises the steps of conveying a bar conveyed by a K1 finished product rolling mill to an oxygen enrichment channel area for oxygen quenching, providing oxygen input inside the oxygen enrichment channel area, and quickly forming an oxide film on the surface of the bar;
carrying out multistage sectional cooling temperature control of medium water pressure and low water content on the bar after the oxygen quenching is finished through a sectional multistage cooling control channel area;
conveying the cooled and temperature-controlled bar material to a cooling bed;
the segmented multistage cooling control channel area comprises a first cooling water tank, a second cooling water tank, a third cooling water tank, a fourth cooling water tank and a fifth cooling water tank, and a plurality of groups of nozzles for providing cooling water are arranged in the cooling water tanks.
As a preferable technical scheme of the invention, the oxygen-enriched channel area is of a fully-enclosed non-closed channel structure, and the flow of oxygen input is 2-6 m 3 The pressure value of the oxygen meter is 0.2-0.3 MPa.
As a preferable technical scheme of the invention, the channel length of the oxygen-enriched channel area is at least two meters.
As a preferable technical scheme of the invention, the flow of the cooling water of the first cooling water tank is 120-140 m 3 The flow rate of the cooling water of the second cooling water tank is 100-120 m 3 The flow rate of the cooling water of the third cooling water tank is 80-100 m 3 H, cooling water flow of the fourth cooling water tankThe amount is 100 to 120m 3 The flow rate of the cooling water of the fifth cooling water tank is 60-80 m 3 /h。
As a preferable technical scheme, the water pressure of the cooling water in the segmented multistage controlled cooling channel area is 0.6-0.8 MPa.
Compared with the prior art, the invention has the beneficial effects that:
according to the novel technology application process for bar oxygen quenching, the bar is additionally provided with the oxygen quenching process between the K1 finished product process and the multistage controlled cooling process, so that an oxide film can be quickly formed on the surface of the bar, the thickness of a primary film on the surface of the bar can be effectively increased in an oxygen-enriched environment, the red rust condition can be effectively reduced, the temperature range where red rust occurs is compressed, the red rust is solved, the temperature of an upper cooling bed can be effectively reduced, the proportion content of alloy manganese and manganese required in bar production is reduced, the production cost is reduced, and the profit space is improved.
Additional features and advantages of the invention will be set forth in the detailed description which follows.
Detailed Description
The technical solutions in the embodiments of the present invention will be described clearly and completely below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
The oxidation process of metals is a heterogeneous reaction between the gas-solid phase. The growth of the iron scale on the surface of the steel is a process of gradually thickening, and generally, the formation of the iron scale is divided into two stages, namely a primary film formation stage and an iron scale thickening and growing stage. In an oxidation environment, the growth rate of the primary film is extremely high, and an extremely thin oxide film is rapidly generated; during the growth thickening process, the oxidation rate is controlled by the stable diffusion of Fe and O atoms in the oxide film. And Fe 2 O 3 The depth of red color of (A) depends on the fine Fe 2 O 3 The proportion and the ratio of particles (less than or equal to 2 mu m)The higher the case, the darker the red. Therefore, the cooling water forms powdered Fe under the chilling action after contacting with the high-temperature red steel 2 O 3 The method is mainly used for preventing red rust on the surface of the deformed steel bar, and the thickness of an initial film is increased and the crushing and pulverization of surface iron scale in the water cooling process are reduced to avoid the formation of the red rust on the surface of the deformed steel bar.
The inventor obtains through many years of production experience and experiments that the temperature of the upper cooling bed has certain correlation with the red rust phenomenon of the finished bar, and the red rust condition appears on the surface of the bar in the production process when the oxygen quenching process is not adopted in the traditional prior art as follows:
(1) when the temperature of the finished product on the cooling bed is 870-890 ℃, the surface quality of the finished product is normal;
(2) when the temperature of the steel is 850-870 ℃ on a cooling bed, the red rust of the finished product is not obvious, and the tail steel has certain red rust;
(3) when the temperature of the finished product on a cooling bed is 830-850 ℃, the red rust of the finished product is obvious;
(4) when the temperature of the finished product on a cooling bed is 780-830 ℃, the red rust of the finished product is obvious;
(5) when the temperature of the finished product on a cooling bed is 730-760 ℃, the finished product basically has no red rust, but the surface color is obviously dark, and the appearance quality of the finished product is seriously influenced.
In the prior art, in order to solve the problem of red rust, the temperature of an upper cooling bed needs to be increased, red rust does not appear when the temperature of the upper cooling bed of a bar is increased to 870-890 ℃, but when the temperature of the upper cooling bed of the bar is increased to 870-890 ℃, the alloy manganese Mn content of a high-speed bar is required to be more than 1.18% in order to ensure the satisfactory strength of a finished bar product, and the alloy manganese Mn content of a common bar is more than 1.35%, but the green reduction production concept of 'replacing metal with water' is obviously not met, so that the production cost is increased, and the profit space is reduced (a temperature interval can generate certain fluctuation due to the steel specification, chemical components, finished product speed, initial rolling temperature, finish rolling temperature and turbid circulating water quality).
The invention provides a technical scheme that: a technology for quenching bar with oxygen features that the bar delivered by K1 rolling mill is quenched by oxygenConveying to an oxygen-enriched channel area for oxygen quenching, wherein oxygen is supplied to the inside of the oxygen-enriched channel area, the oxygen-enriched channel area is of a fully-enclosed non-closed channel structure, and the flow rate of the oxygen input is 2m 3 H, the pressure value of an oxygen meter is 0.2MPa, and an oxide film is rapidly formed on the surface of the bar;
in the invention, the bar is additionally provided with the oxygen quenching process between the K1 finished product process and the multi-stage controlled cooling process, so that an oxide film can be rapidly formed on the surface of the bar, the thickness of a primary film on the surface of the bar can be effectively increased in an oxygen-enriched environment, and the red rust occurrence condition can be effectively reduced;
the bar after oxygen quenching is sequentially subjected to multistage sectional cooling temperature control of medium water pressure and low water volume by a first cooling water tank, a second cooling water tank, a third cooling water tank, a fourth cooling water tank and a fifth cooling water tank of a sectional multistage cooling control channel region, and a plurality of groups of nozzles for providing cooling water are arranged in the cooling water tanks; the flow of cooling water in the first cooling water tank is 120m 3 The flow rate of the cooling water of the second cooling water tank is 100m 3 The flow rate of the cooling water of the third cooling water tank is 80m 3 H, the flow rate of the cooling water in the fourth cooling water tank is 100m 3 The flow rate of the cooling water of the fifth cooling water tank is 60m 3 And h, the water pressure of the cooling water in the segmented multistage cooling control channel area is 0.6 MPa.
And conveying the bar subjected to cooling temperature control to a cooling bed.
According to the invention, the first cooling water tank, the second cooling water tank, the third cooling water tank, the fourth cooling water tank and the fifth cooling water tank in the middle-section multistage cooling control channel region are utilized to realize low-water-pressure multistage cooling control, wherein the low-water-pressure multistage cooling control is used for reducing the deformation cracking and the chilling cracking of cooling water on the surface of a bar, and the medium water pressure is used for timely extruding and discharging bubbles formed in the chilling process so as to avoid pulverization formed in the subsequent air cooling process.
In the invention, the length of the oxygen-enriched channel area is two meters, and the length can meet the requirement of rapid oxidation of the bar material in the oxygen-enriched channel area.
The process of the invention is adopted, and the red rust condition appears on the surface of the bar during production:
(1) when the temperature of the finished product on the cooling bed is 870-890 ℃, the surface quality of the finished product is normal;
(2) when the temperature of the finished product on a cooling bed is 850-870 ℃, the surface quality of the finished product is normal;
(3) when the temperature of the finished product on the cooling bed is 830-850 ℃, the surface quality of the finished product is normal;
(4) when the temperature of the finished product on a cooling bed is 780-830 ℃, the surface quality of the finished product is normal, but occasional batches of the finished product have no obvious red rust, and the tail steel has certain red rust;
(5) when the temperature of the finished product on a cooling bed is 730-760 ℃, the finished product basically has no red rust, but the surface color is obviously dark, and the appearance quality of the finished product is seriously influenced.
Through years of production experience and experimental results of an inventor, the process applied by the novel bar oxygen quenching technology can reduce the temperature of the red rust phenomenon of the bar on a cooling bed by at least 40 ℃, compress the temperature range of the red rust phenomenon of the bar to 30-50 ℃, and when the temperature of the cooling bed is 830 ℃ or above, the red rust phenomenon is not found, so that the production requirement is greatly met, when the temperature of the cooling bed is 830 ℃, the proportion content of the alloy manganese Mn in the high-speed bar is 1.11-1.13%, the proportion content of the alloy manganese Mn in the ordinary bar is 1.28-1.30%, the proportion content of the alloy manganese Mn required by bar production is reduced, the production cost is reduced, and the profit space is improved.
Therefore, this technology is through letting the rod add the oxygen quenching technology between K1 finished product process and multistage accuse cold process, can make the rod surface form the oxide film fast, and under the oxygen boosting environment, can effectively promote the thickness of rod surface primary film, can effectively reduce the condition that red rust appears, thereby the temperature interval that red rust appears in the compression, realize solving under the red rust's the prerequisite, can effectively reduce the cold bed temperature, required alloy manganese Mn's proportion content when reducing the rod production, and therefore the production cost is reduced, and the profit margin is improved.
Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.
Claims (5)
1. A novel technology application process for bar oxygen quenching is characterized in that the process comprises the steps of conveying a bar conveyed by a K1 finished product rolling mill to an oxygen enrichment channel area for oxygen quenching, providing oxygen input inside the oxygen enrichment channel area, and quickly forming an oxidation film on the surface of the bar;
carrying out multistage sectional cooling temperature control of medium water pressure and low water quantity on the bar material after oxygen quenching through a sectional multistage cooling control channel area;
conveying the cooled and temperature-controlled bar material to a cooling bed;
the segmented multistage cooling control channel area comprises a first cooling water tank, a second cooling water tank, a third cooling water tank, a fourth cooling water tank and a fifth cooling water tank, and a plurality of groups of nozzles for providing cooling water are arranged in the cooling water tanks.
2. The process of claim 1, wherein the oxygen-enriched channel region is a fully-enclosed and non-enclosed channel structure, and the flow rate of oxygen input is 2-6 m 3 The pressure value of the oxygen meter is 0.2-0.3 MPa.
3. The process of claim 1, wherein the oxygen-enriched channel zone has a channel length of at least two meters.
4. The novel bar oxygen quenching technology application process as claimed in claim 1, wherein the flow rate of the cooling water in the first cooling water tank is 120-140 m 3 The flow rate of the cooling water of the second cooling water tank is 100-120 m 3 The flow rate of the cooling water of the third cooling water tank is 80-100 m 3 The flow rate of the cooling water of the fourth cooling water tank is 100-120 m 3 H, saidThe flow rate of cooling water of the fifth cooling water tank is 60-80 m 3 /h。
5. The process of claim 1, wherein the water pressure of the cooling water in the segmented multistage controlled cooling channel region is 0.6-0.8 MPa.
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| CN202210465718.2A CN114990309A (en) | 2022-04-29 | 2022-04-29 | Novel bar oxygen quenching technology application process |
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Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080169050A1 (en) * | 2007-01-15 | 2008-07-17 | Sl Steel Group Holding Company Limited | Method for manufacturing prime hot rolled high tensile strength deformed bars |
| CN106111698A (en) * | 2016-07-16 | 2016-11-16 | 首钢总公司 | A kind of controlled rolling and controlled cooling reinforcing bar hinders the production method of rust online |
| CN107185968A (en) * | 2017-06-21 | 2017-09-22 | 北京科技大学 | A kind of excellent special steel bar controlled rolling and controlled cooling method |
| CN110560490A (en) * | 2019-08-26 | 2019-12-13 | 中冶赛迪工程技术股份有限公司 | process method for controlling temperature of wire rod and inhibiting surface red rust |
| CN111360066A (en) * | 2020-02-21 | 2020-07-03 | 中冶赛迪工程技术股份有限公司 | Low-cost, less-red-rust, high-strength and anti-seismic deformed steel bar production method and system |
| CN112246888A (en) * | 2020-09-08 | 2021-01-22 | 福建泉州闽光钢铁有限责任公司 | Production method for improving surface quality of finish-rolled twisted steel |
| CN112536321A (en) * | 2020-11-23 | 2021-03-23 | 山东钢铁股份有限公司 | Cold control method for small-specification bearing steel |
| CN213256297U (en) * | 2020-09-08 | 2021-05-25 | 福建泉州闽光钢铁有限责任公司 | Improved finish rolling twisted steel water cooling device |
| CN113814281A (en) * | 2021-09-03 | 2021-12-21 | 广西钢铁集团有限公司 | Cost-reducing segmented cooling control method for hot-rolled ribbed steel bar |
-
2022
- 2022-04-29 CN CN202210465718.2A patent/CN114990309A/en active Pending
Patent Citations (9)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20080169050A1 (en) * | 2007-01-15 | 2008-07-17 | Sl Steel Group Holding Company Limited | Method for manufacturing prime hot rolled high tensile strength deformed bars |
| CN106111698A (en) * | 2016-07-16 | 2016-11-16 | 首钢总公司 | A kind of controlled rolling and controlled cooling reinforcing bar hinders the production method of rust online |
| CN107185968A (en) * | 2017-06-21 | 2017-09-22 | 北京科技大学 | A kind of excellent special steel bar controlled rolling and controlled cooling method |
| CN110560490A (en) * | 2019-08-26 | 2019-12-13 | 中冶赛迪工程技术股份有限公司 | process method for controlling temperature of wire rod and inhibiting surface red rust |
| CN111360066A (en) * | 2020-02-21 | 2020-07-03 | 中冶赛迪工程技术股份有限公司 | Low-cost, less-red-rust, high-strength and anti-seismic deformed steel bar production method and system |
| CN112246888A (en) * | 2020-09-08 | 2021-01-22 | 福建泉州闽光钢铁有限责任公司 | Production method for improving surface quality of finish-rolled twisted steel |
| CN213256297U (en) * | 2020-09-08 | 2021-05-25 | 福建泉州闽光钢铁有限责任公司 | Improved finish rolling twisted steel water cooling device |
| CN112536321A (en) * | 2020-11-23 | 2021-03-23 | 山东钢铁股份有限公司 | Cold control method for small-specification bearing steel |
| CN113814281A (en) * | 2021-09-03 | 2021-12-21 | 广西钢铁集团有限公司 | Cost-reducing segmented cooling control method for hot-rolled ribbed steel bar |
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