CN116676465A - Bottom roller cooling device and process of heat treatment furnace - Google Patents

Bottom roller cooling device and process of heat treatment furnace Download PDF

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Publication number
CN116676465A
CN116676465A CN202310773263.5A CN202310773263A CN116676465A CN 116676465 A CN116676465 A CN 116676465A CN 202310773263 A CN202310773263 A CN 202310773263A CN 116676465 A CN116676465 A CN 116676465A
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China
Prior art keywords
roller
heat treatment
treatment furnace
cooling
air
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CN202310773263.5A
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Chinese (zh)
Inventor
王琨铭
廖桑桑
张亚君
蔡芳澜
唐小勇
邹锦忠
赵敏森
张留洪
蒋星亮
刘志芳
杨帆
郑景斌
熊雄
周焱民
汪承星
阳隽觎
周启航
李磊
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Xinyu Iron and Steel Co Ltd
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Xinyu Iron and Steel Co Ltd
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Priority to CN202310773263.5A priority Critical patent/CN116676465A/en
Publication of CN116676465A publication Critical patent/CN116676465A/en
Pending legal-status Critical Current

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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
    • C21D9/0006—Details, accessories not peculiar to any of the following furnaces
    • C21D9/0025—Supports; Baskets; Containers; Covers
    • 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
    • C21D1/26—Methods of annealing
    • C21D1/28—Normalising
    • 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
    • C21D1/62—Quenching devices
    • 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
    • C21D1/74—Methods of treatment in inert gas, controlled atmosphere, vacuum or pulverulent material
    • 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
    • C21D11/00—Process control or regulation for heat treatments
    • 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
    • C21D9/0081—Heat treatment, e.g. annealing, hardening, quenching or tempering, adapted for particular articles; Furnaces therefor for slabs; for billets
    • 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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  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Thermal Sciences (AREA)
  • Crystallography & Structural Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Tunnel Furnaces (AREA)

Abstract

The invention provides a heat treatment furnace bottom roller cooling device and a process, which relate to the field of machine manufacturing, and comprise a compressed air circulation pipe network and an asbestos fiber roller, wherein the asbestos fiber roller comprises an alloy roller and a fiber layer wrapped on the surface of the alloy roller, the center of the alloy roller is provided with a central cooling air passage penetrating along the length direction of the alloy roller, and two ends of the central cooling air passage are connected to the compressed air circulation pipe network; and a plurality of surface cooling air passages arranged along the length direction of the alloy roller are also arranged in the alloy roller, and are all close to the fiber layer and communicated with the central cooling air passage. The invention can reduce the temperature difference between the roller core and the roller surface, reduce the cracking risk of high temperature resistant asbestos fiber, prolong the service life, and reduce the heat in the furnace and reduce the energy consumption due to the improvement of cooling uniformity.

Description

Bottom roller cooling device and process of heat treatment furnace
Technical Field
The invention relates to the field of machine manufacturing, in particular to a bottom roller cooling device and a bottom roller cooling process of a heat treatment furnace.
Background
Along with the continuous improvement of national economy, the demand for high-performance high-quality wide and thick steel plates is increased year by year, in order to obtain good performance and quality, heat treatment processes such as quenching, tempering, normalizing and the like are often needed to be carried out, a common heat treatment furnace is mainly a roller hearth heat treatment furnace, a walking beam heat treatment furnace and a trolley heat treatment furnace, wherein the roller hearth heat treatment furnace is widely applied to various large steel factories in China due to the advantages of uniform heating, low furnace atmosphere control, low energy consumption, high production efficiency and the like, but in the production and use process, oxidized iron scales remained on the lower surface of a steel plate are adhered to the surface of a furnace bottom roller made of high-temperature alloy steel material, nodulation is generated after the steel plate is rolled, irregular convex points are formed, pits are generated after the lower surface of the steel plate passes through the nodulation furnace roller during the heat treatment, the defect is light, polishing treatment is needed, and the steel plate is scrapped due to the heavy steel plate.
According to the research of the inventor, in order to solve the problem of the nodulation of the hearth roll, some factories adopt a method of cooling the heat treatment furnace to 400-500 ℃ and then feeding the grooved steel plate into the furnace for repeated furnace sliding, the method has the advantages that the cooling process is slow, the operation rate of the heat treatment furnace is influenced, the hearth roll surface is easy to scratch, the nodulation is easy to generate again in a short period after the nodulation is removed, the furnace sliding needs to be cooled every 7-10 days on average, and the production efficiency is seriously influenced by the repeated furnace sliding. Some high-temperature-resistant fiber furnace rollers are divided into a non-water-passing type and a water-passing type, the problem of nodulation on the surface of the furnace bottom roller is effectively solved by the non-water-passing type, but the furnace roller cannot be effectively cooled, and the heat-resistant fiber on the surface of the furnace roller is easy to crack and has short service life; the water-passing type fiber roller is cooled by passing water through the center of the roller on the basis of the water-non-passing type roller, so that the service life is prolonged, but the roller surface cannot be cooled effectively in the cooling process, the temperature difference is formed on the roller body, the roller body deforms after a period of use, the fiber roller surface still can crack, and meanwhile, industrial circulating water is used to cause scaling of the furnace roller and the pipeline, so that the cooling effect is affected.
Disclosure of Invention
The invention aims to provide a bottom roller cooling device and a process of a heat treatment furnace, which can reduce the temperature difference between a roller center and a roller surface, reduce the cracking risk of high-temperature-resistant asbestos fibers, prolong the service life, and simultaneously reduce the heat in the furnace and reduce the energy consumption due to the improvement of cooling uniformity.
Embodiments of the present invention are implemented as follows:
in a first aspect, the present invention provides a bottom roller cooling apparatus for a heat treatment furnace, comprising:
a compressed air circulation pipe network;
the asbestos fiber roller comprises an alloy roller and a fiber layer wrapping the surface of the alloy roller, a central cooling air passage penetrating along the length direction of the alloy roller is arranged in the center of the alloy roller, and two ends of the central cooling air passage are connected to the compressed air circulating pipe network through an air pipeline;
and a plurality of surface cooling air passages are arranged in the alloy roller along the length direction of the alloy roller, and are close to the fiber layers and communicated with the central cooling air passage.
In an alternative embodiment, four surface cooling air passages are provided, and the four surface cooling air passages are uniformly and equidistantly distributed on the alloy roll and near the fiber layer.
In an alternative embodiment, the diameter of the central cooling air passage is 1/4 to 1/5 of the diameter of the alloy roller, and the diameter of the central cooling air passage is 2 to 3 times of the diameter of the surface cooling air passage.
In an alternative embodiment, the alloy roller is provided with a plurality of cross-shaped air passages along the length direction of the alloy roller, and each cross-shaped air passage is communicated with four surface cooling air passages and four central cooling air passages.
In an alternative embodiment, the cross-shaped air passages are 45 ° from the sides of the central cooling air passage.
In an alternative embodiment, 10-20 cross-shaped air passages are arranged in total and equidistantly along the length direction of the alloy roller, and the diameter of the cross-shaped air passages is 1/10-1/20 of that of the surface cooling air passages.
In an alternative embodiment, an air temperature detector is arranged on the air pipeline, and an air flow control electromagnetic valve is arranged at the joint of the air pipeline and the air circulation pipe network.
In a second aspect, the present invention provides a heat treatment furnace bottom roll cooling process, including any one of the heat treatment furnace bottom roll cooling devices described above, comprising the steps of;
s1: when the temperature of the heat treatment furnace is 200-550 ℃, the cooling is not required to be started at the stage, and the air inflow is 0m 3 And/h, the outlet flow is 0m 3 /h；
S2: when the temperature of the heat treatment furnace is higher than 550 ℃, a compressed air circulation pipe network is started, wherein when the temperature of the heat treatment furnace is 551-700 ℃, the air inlet temperature is less than or equal to 25 ℃, the air outlet temperature is controlled to be 25-50 ℃, and the air inlet flow is controlled to be 100-150 m 3 And/h, controlling the air outlet flow to be 95-145 m 3 And/h, the flow rate of the inlet gas and the flow rate of the outlet gas are more than or equal to 5m 3 ；
When the temperature of the heat treatment furnace is 701-800 ℃, the gas inlet temperature is less than or equal to 25 ℃, the gas outlet temperature is controlled to be 25-45 ℃, and the gas inlet flow is controlled to be 270-320 3 And/h, controlling the air outlet flow to be 265-315 m 3 And/h, the flow rate of the inlet gas and the flow rate of the outlet gas are more than or equal to 5m 3 ；
When the temperature of the heat treatment furnace is 801-950 ℃, the gas inlet temperature is less than or equal to 25 ℃, the gas outlet temperature is controlled to be 25-40 ℃, and the gas inlet flow is controlled to be 295-345 3 And/h, controlling the air outlet flow to be 290-340 m 3 And/h, the flow rate of the inlet gas and the flow rate of the outlet gas are more than or equal to 5m 3 。
In an alternative embodiment, shot blasting treatment and pre-straightening treatment are required before the steel plate is fed into the furnace, the roughness of the upper surface and the lower surface of the steel plate before the steel plate is fed into the furnace reaches Sa2.5 level, and the flatness reaches 2mm/1m.
In an alternative embodiment, nitrogen is filled into the furnace when the heat treatment furnace runs, so that the furnace is in a micro-positive pressure state, the residual oxygen content in the furnace is ensured to be less than or equal to 100ppm, the purity of the nitrogen is ensured to be more than or equal to 99.99%, the pressure of the nitrogen is 0.3-0.5 Mpa, and the pressure of a hearth is 10-25 Pa.
The embodiment of the invention has the beneficial effects that:
the invention provides a heat treatment furnace bottom roller cooling device, which comprises: the compressed air circulation pipe network and the asbestos fiber roller comprise an alloy roller and a fiber layer wrapping the surface of the alloy roller; by using the ventilation high-temperature-resistant asbestos fiber roller, certain elasticity exists on the surface of the asbestos fiber roller, and scale on the lower surface of the steel plate cannot form compacted knots on the surface of the asbestos fiber roller, so that the defect of bottom roll marks on the lower surface of the heat treatment plate is eliminated.
In addition, be provided with the central cooling air flue that runs through along self length direction at the center of alloy roller, the both ends of central cooling air flue are connected on compressed air circulation pipe net, still are provided with many surface cooling air flue that set up along self length direction in the alloy roller, and many surface cooling air flue all are close to the fibrous layer and communicate central cooling air flue. Meanwhile, in the production process, the air inlet flow is controlled to be slightly larger than the air outlet flow, so that the air duct is in a micro-positive pressure state, and compressed air is ensured to be filled in the whole asbestos fiber roller; through the micro positive pressure state in the surface cooling air passage and the ventilation pipeline, the uniformity and the cooling efficiency of the roller body cooling are improved.
In addition, the gas temperature of the gas inlet pipeline and the gas outlet pipeline is dynamically adjusted, the temperature of the high-temperature-resistant alloy roller of the asbestos fiber roller at the bottom of the furnace is ensured to be lower than 550 ℃, the power of the gas cooling equipment is increased when the gas inlet temperature is too high, and the flow control electromagnetic valve is used for increasing the gas inlet flow when the gas outlet temperature is too high, and vice versa. The operation method is combined with the structure, so that the problem of cracking of the surface fiber layer caused by deformation of the roller body is avoided, the energy consumption is reduced, the service life of the roller is up to 12-15 months, the repeated temperature rise and fall of a heat treatment furnace are avoided, the operation rate of the heat treatment furnace is effectively improved, the yield of a heat treatment plate is increased, and the gas consumption is 15% lower than that of a water-through high-temperature-resistant fiber roller.
And finally, the compressed air circulation pipe network is used for replacing industrial circulating water to cool the roller body, so that the problem that the cooling effect is influenced by scaling of a cooling pipeline due to excessive impurities of the industrial circulating water is avoided, and the service life is further prolonged.
Drawings
In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.
FIG. 1 is a schematic view of a bottom roller cooling apparatus of a heat treatment furnace according to an embodiment of the present invention;
fig. 2 is a schematic diagram of a second view angle of a bottom roller cooling device of a heat treatment furnace according to an embodiment of the invention.
Icon:
100-compressed air circulation pipe network; 200-asbestos fiber rollers; 210-alloy roller; 211-central cooling air duct; 212-surface cooling airways; 213-cross airway; 220-fiber layers; 300-ventilation duct; 400-air thermometer; 500-air flow control solenoid valve.
Detailed Description
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments of the present invention. The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.
In the description of the present invention, it should be noted that, directions or positional relationships indicated by terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., are directions or positional relationships based on those shown in the drawings, or are directions or positional relationships conventionally put in use of the inventive product, are merely for convenience of describing the present invention and simplifying the description, and are not indicative or implying that the apparatus or element to be referred to must have a specific direction, be constructed and operated in a specific direction, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," "third," and the like are used merely to distinguish between descriptions and should not be construed as indicating or implying relative importance.
Furthermore, the terms "horizontal," "vertical," and the like do not denote a requirement that the component be absolutely horizontal or overhang, but rather may be slightly inclined. As "horizontal" merely means that its direction is more horizontal than "vertical", and does not mean that the structure must be perfectly horizontal, but may be slightly inclined.
In the description of the present invention, it should also be noted that, unless explicitly specified and limited otherwise, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
As shown in fig. 1 and 2, the present embodiment provides a heat treatment furnace bottom roller cooling apparatus, comprising: the compressed air circulation pipe network 100 and the asbestos fiber roller 200, wherein the asbestos fiber roller 200 comprises an alloy roller 210 and a fiber layer 220 wrapped on the surface of the alloy roller 210, a central cooling air passage 211 penetrating along the length direction of the alloy roller 210 is arranged at the center of the alloy roller 210, and two ends of the central cooling air passage 211 are connected to the compressed air circulation pipe network 100 through an air pipe 300; the alloy roller 210 is further provided with a plurality of surface cooling air passages 212 arranged along the length direction thereof, and the plurality of surface cooling air passages 212 are close to the fiber layer 220 and are communicated with the central cooling air passage 211. In detail, one end of the surface cooling air passage 212 may be connected to an air inlet pipe of the compressed air circulation pipe network 100, and the other end is in a closed state, so that the compressed air in the surface cooling air passage returns to the compressed air circulation pipe network 100 through the central cooling air passage 211.
It can be understood that, in this embodiment, by using the asbestos fiber roller 200 with ventilation and high temperature resistance, by using a certain elasticity of the surface of the asbestos fiber roller 200, the scale on the lower surface of the steel plate cannot form compacted knots on the surface of the asbestos fiber roller 200; in addition, the asbestos fiber roller 200 with ventilation and high temperature resistance is used, the defect of bottom roller mark of the lower surface of the heat treatment plate is eliminated, meanwhile, the uniformity and cooling efficiency of roller body cooling are improved through the surface cooling air passage 212, the cracking problem of the surface fiber layer 220 caused by roller body deformation is avoided, meanwhile, the energy consumption is reduced, the service life of the asbestos fiber roller is 12-15 months, the repeated temperature rise and fall of a heat treatment furnace is avoided, the operation rate of the heat treatment furnace is effectively improved, the yield of the heat treatment plate is increased, and the gas consumption is 15% lower than that of the high temperature resistant fiber roller with ventilation and water. In addition, the compressed air circulation pipe network 100 is used for replacing industrial circulating water to cool the roller body, so that the problem that the cooling effect is influenced by scaling of the cooling pipeline due to the fact that the industrial circulating water is more impurity is avoided, and the service life is further prolonged.
Specifically, four surface cooling air passages 212 are provided, and four surface cooling air passages 212 are uniformly and equidistantly distributed over alloy roll 210 and in close proximity to fiber layer 220.
In the present embodiment, four surface cooling air passages 212 are provided, but the present invention is not limited thereto, and in other embodiments, five, six, etc. surface cooling air passages 212 may be provided, and the equivalent of the present embodiment can achieve the effects of the present embodiment, which are all within the scope of the present embodiment.
Further, the diameter of the central cooling air passage 211 is 1/4 to 1/5 of the diameter of the alloy roll 210. It will be appreciated that the specific diameter of the central cooling air passage 211 is determined according to the actual working condition, if the temperature of the asbestos fiber roller 200 is high in the actual working condition, the diameter of the central cooling air passage 211 can be appropriately increased, and otherwise, the diameter of the central cooling air passage 211 can be reduced.
Specifically, the diameter of the central cooling air passage 211 is 2 to 3 times that of the surface cooling air passage 212. It will be appreciated that since the compressed air in the surface cooling passages 212 is discharged through the central cooling passage 211, the diameter of the central cooling passage 211 is 2 to 3 times, particularly, more than the diameter of the surface cooling passages 212, depending on the compressed air supplied from the compressed air circulation network 100, in order to enable rapid discharge of the compressed air in the surface cooling passages 212 and the central cooling passages 211 and to enhance the cooling effect.
In this embodiment, the alloy roller 210 is provided with a plurality of cross-shaped air passages 213 along its own length direction, and each cross-shaped air passage 213 communicates with four surface cooling air passages 212 and the center cooling air passage 211. It can be appreciated that when the purpose of setting the plurality of cross air passages 213 to connect the surface cooling air passages 212 and the central cooling air passage 211 is to discharge heat of the roller surface through the central cooling air passage 211 better, the temperature difference between the roller core and the roller surface is reduced, the cracking risk of the high temperature resistant asbestos fiber is reduced, and the cooling uniformity is further improved.
Specifically, the cross-shaped air passages 213 are 45 ° to the sides of the central cooling air passage 211. It can be appreciated that the cross-shaped air passage 213 forms a certain angle with the central cooling air passage 211, so that the resistance of the compressed air in the surface cooling air passage 212 when entering the central cooling air passage 211 can be reduced, the compressed air in the surface cooling air passage 212 can be quickly subjected to heat exchange, and the temperature of the surface of the asbestos fiber roller 200 is cooled, and finally, the embodiment determines that 45 ° is the optimal angle through multiple experiments.
Specifically, 10 to 20 in total are provided for the cross-shaped air passages 213, and are equidistantly provided along the length direction of the alloy roller 210, and the diameter of the cross-shaped air passages 213 is 1/10 to 1/20 of that of the surface cooling air passages 212. It is noted that the number of the cross-shaped air passages 213 in the present embodiment is inversely proportional to the diameter of the cross-shaped air passages 213, and when the number of the cross-shaped air passages 213 is 15, the diameter of the cross-shaped air passages 213 is 1/15 of the surface cooling air passages 212, and such matching setting is advantageous for heat exchange between the center cooling air passage 211 and the surface cooling air passages 212.
In this embodiment, an air thermometer 400 is provided on the ventilation pipe 300. It will be appreciated that air thermometer 400 is primarily used to measure the temperature of compressed air; the two air thermometers 400 are respectively arranged on the air ducts 300 connected with the two ends of the central cooling air passage 211, and are respectively used for detecting the temperature of the compressed air entering the central cooling air passage 211 and the temperature of the compressed air exiting the central cooling air passage 211.
In this embodiment, an air flow control solenoid valve 500 is disposed at the connection between the ventilation pipe 300 and the air circulation pipe network. Specifically, the air flow control solenoid valve 500 is provided for controlling the flow rate of compressed air, so that the asbestos fiber roller 200 can achieve an optimal cooling effect under different working conditions, and the service life of the device is prolonged.
Specifically, the alloy roll 210 is a roll made of tungsten carbide, cobalt, or the like, which is made of a material by a powder metallurgy method.
In addition, in this embodiment, through repeated experiments, in order to achieve both the cooling effect and the processing cost, the diameter of the central cooling air passage 211 is designed to be 1/5 of the diameter of the superalloy roller 210, meanwhile, in order to facilitate compressed air in the surface cooling air passage 212 to enter the central air passage, the diameter of the central cooling air passage 211 is designed to be 2 times that of the surface cooling air passage 212, the diameter of the cross-shaped air passage 213 is determined according to the number of the cross-shaped air passages, as shown in fig. 1, 18 herringbone air passages are arranged, the diameter of the cross-shaped air passage 213 is just 1/18 of the near-surface air passage, the side angle between the cross-shaped air passage 213 and the central cooling air passage 211 is 45 ℃, the heat in the roller body is taken away by the central cooling air passage 211 and the surface cooling air passage 212 through heat exchange, and the air inlet flow is controlled to be slightly greater than the air outlet flow in the production process, so that the whole air passage 300 is in a micro-positive pressure state, the whole air passage is ensured to be full of the whole air passage, the effect of uniformly cooling the roller body of the asbestos fiber roller 200 is achieved, the roller body temperature of the alloy roller 210 is kept in a range below 550 ℃ uniformly, and the roller body temperature is not obvious, and the high temperature creep phenomenon of the roller body does not occur.
The embodiment also provides a bottom roller cooling process of the heat treatment furnace. The method comprises the following steps:
s1: when the temperature of the heat treatment furnace is 200-550 ℃, the cooling is not required to be started at the stage, and the air inflow rate is maintained to be 0m 3 And/h, the outlet flow is 0m 3 /h；
S2: when the temperature of the heat treatment furnace is higher than 550 ℃, a compressed air circulation pipe network is started, wherein when the temperature of the heat treatment furnace is 551-700 ℃, the air inlet temperature is less than or equal to 25 ℃, the air outlet temperature is controlled to be 25-50 ℃, and the air inlet flow is controlled to be 100-150 m 3 And/h, controlling the air outlet flow to be 95-145 m 3 And/h, the flow rate of the inlet gas and the flow rate of the outlet gas are more than or equal to 5m 3 ；
When the temperature of the heat treatment furnace is 701-800 ℃, the gas inlet temperature is less than or equal to 25 ℃, the gas outlet temperature is controlled to be 25-45 ℃, and the gas inlet flow is controlled to be 270-320 3 And/h, controlling the air outlet flow to be 265-315 m 3 And/h, the flow rate of the inlet gas and the flow rate of the outlet gas are more than or equal to 5m 3 ；
When the temperature of the heat treatment furnace is 801-950 ℃, the gas inlet temperature is less than or equal to 25 ℃, the gas outlet temperature is controlled to 25-40 ℃, and the gas inlet flow is controlled to 295-345 3 And/h, controlling the air outlet flow to be 290-340 m 3 And/h, the flow rate of the inlet gas and the flow rate of the outlet gas are more than or equal to 5m 3 。
It should be noted that during the production process, the ventilation pipe 300 is in a micro-positive pressure state by controlling the inflow rate slightly larger than the outflow rate, so as to ensure that the compressed gas fills the whole asbestos fiber roller 200.
The gas temperature of the gas inlet pipeline and the gas outlet pipeline is dynamically adjusted, the temperature of the high-temperature resistant alloy roller 210 of the asbestos fiber roller 200 at the bottom of the furnace is guaranteed to be lower than 550 ℃, the power of gas cooling equipment is increased when the gas inlet temperature is too high, and the flow control electromagnetic valve is used for increasing the gas inlet flow when the gas outlet temperature is too high, and vice versa.
According to the air cooling formula: l=q/[ cp× +× (T1-T2) ] (L: cooling air flow, Q: heat of removal, cp: air specific heat capacity, oc: air specific gravity, T1: temperature after air cooling, T2: temperature before air cooling), alloy roll 210 cooling heat of removal q=c×m× (T3-T4) (C: alloy steel specific heat capacity, M: alloy layer mass, T3: temperature before alloy layer cooling, T4: temperature after air alloy layer cooling).
The temperature of the air outlet in the air duct 300 should not be higher than 50 ℃, and the furnace roller is slowly deformed due to the high temperature creep phenomenon of the high temperature resistant fiber layer 220 at a temperature higher than 550 ℃, so that the furnace roller is started to cool when the temperature of the heat treatment furnace is higher than 550 ℃, and a control gear is arranged every 100-150 ℃ for considering the cooling efficiency and the running cost.
Further, shot blasting treatment and pre-straightening treatment are required before the heat treatment steel plate enters the furnace, the roughness of the upper surface and the lower surface of the steel plate before the steel plate enters the furnace reaches Sa2.5 level, and the flatness reaches 2mm/1m.
Further, nitrogen is charged into the furnace when the heat treatment furnace runs, so that the furnace is in a micro-positive pressure state, the residual oxygen content in the furnace is ensured to be less than or equal to 100ppm, the purity of the nitrogen is ensured to be more than or equal to 99.99%, the pressure of the nitrogen is 0.3-0.5 Mpa, and the pressure of a hearth is 10-25 Pa.
The present invention will be described in further detail with reference to specific examples.
1. Producing 2000t steel CCSE550 with the thickness of 6-100 mm, and carrying out heat treatment: quenching and tempering, wherein the quenching temperature is 930 ℃ and the tempering temperature is 660 ℃. Before entering the furnace, firstly, performing shot blasting and pre-straightening on each steel plate to ensure that the surface of each steel plate has no oxide scale, the roughness reaches Sa2.5 level, the flatness is less than or equal to 2mm/1m, and during quenching, the temperature of entering air is monitored to be controlled below 25 ℃, and the temperature of exiting air is monitored to ensure that the temperature of exiting air is within the range of 30-40 ℃. During tempering, the temperature of the gas outlet is controlled at 40-50 ℃, the nitrogen pressure is controlled, the nitrogen flow is stabilized, the residual oxygen in the furnace is ensured to be less than or equal to 100ppm during quenching and tempering, the pressure of the hearth is stabilized at 10-25 Pa, the defect of the bottom roll marks of the lower surface of 1 steel plate does not appear after the production is finished, and the surface quality is good.
2. Producing 5000t steel 16MnDR with thickness of 6-80 mm, and heat treatment process: normalizing, wherein the normalizing temperature is 900 ℃. Before entering the furnace, firstly, performing shot blasting and pre-straightening on each steel plate to ensure that the surface of each steel plate has no oxide scale, the roughness reaches Sa2.5 level, the flatness is less than or equal to 2mm/1m, during normalizing, the temperature of entering air is monitored to be controlled below 25 ℃, and the temperature of exiting air is monitored to ensure that the temperature of exiting air is within the range of 30-40 ℃. Meanwhile, the nitrogen pressure is controlled, the nitrogen flow is stabilized, the residual oxygen in the furnace is ensured to be less than or equal to 100ppm, the furnace pressure is stabilized at 10-25 Pa, the defect of the bottom roll marks of the lower table of 1 steel plate after the production is finished is avoided, and the surface quality is good.
The device and the method for eliminating the defects of the hearth roll marks have the following advantages:
in the embodiment, by using the ventilation high-temperature-resistant asbestos fiber roller 200, certain elasticity exists on the surface of the asbestos fiber roller 200, and the scale on the lower surface of the steel plate cannot form compacted knots on the surface of the asbestos fiber roller 200, so that the defect of bottom roll marks on the lower surface of the heat treatment plate is eliminated.
In addition, a central cooling air passage 211 penetrating along the length direction of the alloy roller 210 is arranged in the center of the alloy roller 210, two ends of the central cooling air passage 211 are connected to the compressed air circulation pipe network 100, a plurality of surface cooling air passages 212 arranged along the length direction of the alloy roller 210 are also arranged in the alloy roller 210, and the surface cooling air passages 212 are close to the fiber layer 220 and are communicated with the central cooling air passage 211. Meanwhile, in the production process, the air inlet flow is controlled to be slightly larger than the air outlet flow, so that the air duct 300 is in a micro-positive pressure state, and compressed air is ensured to be filled in the whole asbestos fiber roller 200; by surface cooling the micro positive pressure conditions within the air passage 212 and the air duct 300, the uniformity of roll body cooling and cooling efficiency are improved.
In addition, the gas temperature of the gas inlet pipeline and the gas outlet pipeline is dynamically adjusted, the temperature of the high-temperature resistant alloy roller 210 of the asbestos fiber roller 200 at the bottom of the furnace is guaranteed to be lower than 550 ℃, the power of the gas cooling equipment is increased when the gas inlet temperature is too high, and the flow control electromagnetic valve is used for increasing the gas inlet flow when the gas outlet temperature is too high, and vice versa. The operation method is combined with the structure, so that the problem of cracking of the surface fiber layer 220 caused by deformation of the roller body is avoided, the energy consumption is reduced, the service life of the roller is up to 12-15 months, the repeated temperature rise and drop of the heat treatment furnace are avoided, the operation rate of the heat treatment furnace is effectively improved, the yield of a heat treatment plate is increased, and the gas consumption is 15% lower than that of a water-through high-temperature-resistant fiber roller.
Finally, the compressed air circulation pipe network 100 is used for replacing industrial circulating water to cool the roller body, so that the problem that the cooling effect is affected by scaling of a cooling pipeline due to excessive impurities of the industrial circulating water is avoided, and the service life is further prolonged.
The above description is only of the preferred embodiments of the present invention and is not intended to limit the present invention, but various modifications and variations can be made to the present invention by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims (10)

1. A bottom roller cooling device of a heat treatment furnace, comprising:
a compressed air circulation pipe network;
the asbestos fiber roller comprises an alloy roller and a fiber layer wrapping the surface of the alloy roller, a central cooling air passage penetrating along the length direction of the alloy roller is arranged in the center of the alloy roller, and two ends of the central cooling air passage are connected to the compressed air circulating pipe network through an air pipeline;
and a plurality of surface cooling air passages are arranged in the alloy roller along the length direction of the alloy roller, and are close to the fiber layers and communicated with the central cooling air passage.
2. A heat treatment furnace bottom roller cooling device according to claim 1, wherein four surface cooling air passages are provided, and four surface cooling air passages are uniformly and equidistantly distributed on the alloy roller at positions close to the fiber layer.
3. A heat treatment furnace hearth roll cooling apparatus according to claim 1, wherein the diameter of the center cooling air passage is 1/4 to 1/5 of the diameter of the alloy roll, and the diameter of the center cooling air passage is 2 to 3 times the diameter of the surface cooling air passage.
4. The heat treatment furnace bottom roller cooling device according to claim 1, wherein the alloy roller is provided with a plurality of cross-shaped air passages along the length direction thereof, and each cross-shaped air passage is communicated with four surface cooling air passages and the central cooling air passage.
5. A heat treatment furnace bottom roll cooling apparatus according to claim 4, wherein the cross-shaped air passage is 45 ° from the side of the central cooling air passage.
6. The heat treatment furnace hearth roll cooling apparatus according to claim 4, wherein 10 to 20 cross-shaped air passages are provided in total and are equidistantly provided along the longitudinal direction of the alloy roll, and the cross-shaped air passages have a diameter of 1/10 to 1/20 of the surface cooling air passages.
7. The heat treatment furnace bottom roller cooling device according to claim 1, wherein an air thermometer is arranged on the air duct, and an air flow control electromagnetic valve is arranged at the joint of the air duct and the air circulation pipe network.
8. A heat treatment furnace bottom roll cooling process, characterized by comprising a heat treatment furnace bottom roll cooling apparatus according to any one of claims 1 to 7, comprising the steps of;
s1: when the temperature of the heat treatment furnace is 200-550 ℃, the cooling is not required to be started at the stage, and the air inflow is 0m 3 And/h, the outlet flow is 0m 3 /h；
S2: when the temperature of the heat treatment furnace is higher than 550 ℃, a compressed air circulation pipe network is started, wherein when the temperature of the heat treatment furnace is 551-700 ℃, the air inlet temperature is less than or equal to 25 ℃, the air outlet temperature is controlled to be 25-50 ℃, and the air inlet flow is controlled to be 100-150 m 3 And/h, controlling the air outlet flow to be 95-145 m 3 And/h, the flow rate of the inlet gas and the flow rate of the outlet gas are more than or equal to 5m 3 ；
When the temperature of the heat treatment furnace is 701-800 ℃, the gas inlet temperature is less than or equal to 25 ℃, the gas outlet temperature is controlled to be 25-45 ℃, and the gas inlet flow is controlled to be 270-320 3 And/h, controlling the air outlet flow to be 265-315 m 3 And/h, the flow rate of the inlet gas and the flow rate of the outlet gas are more than or equal to 5m 3 ；
When the temperature of the heat treatment furnace is 801-950 ℃,the inlet gas temperature is less than or equal to 25 ℃, the outlet gas temperature is controlled to be 25-40 ℃, the inlet gas flow is controlled to be 295-3453/h, and the outlet gas flow is controlled to be 290-340 m 3 And/h, the flow rate of the inlet gas and the flow rate of the outlet gas are more than or equal to 5m 3 。
9. The process for cooling a bottom roller of a heat treatment furnace according to claim 8, wherein the heat-treated steel sheet is subjected to shot blasting and pre-straightening before being fed into the furnace, and the roughness of the upper and lower surfaces of the steel sheet before being fed into the furnace reaches the level Sa2.5 and the flatness reaches 2mm/1m.
10. The process for cooling the bottom roller of the heat treatment furnace according to claim 9, wherein nitrogen is filled into the furnace when the heat treatment furnace is operated, so that the furnace is in a micro-positive pressure state, the residual oxygen content in the furnace is ensured to be less than or equal to 100ppm, the purity of the nitrogen is ensured to be more than or equal to 99.99%, the pressure of the nitrogen is 0.3-0.5 Mpa, and the pressure of a hearth is 10-25 Pa.
CN202310773263.5A 2023-06-28 2023-06-28 Bottom roller cooling device and process of heat treatment furnace Pending CN116676465A (en)

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CN202310773263.5A CN116676465A (en) 2023-06-28 2023-06-28 Bottom roller cooling device and process of heat treatment furnace

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Application Number Priority Date Filing Date Title
CN202310773263.5A CN116676465A (en) 2023-06-28 2023-06-28 Bottom roller cooling device and process of heat treatment furnace

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CN116676465A true CN116676465A (en) 2023-09-01

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