CN117737357A - Quick continuous annealing ultra-high strength strip steel production line - Google Patents
Quick continuous annealing ultra-high strength strip steel production line Download PDFInfo
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- CN117737357A CN117737357A CN202211122619.0A CN202211122619A CN117737357A CN 117737357 A CN117737357 A CN 117737357A CN 202211122619 A CN202211122619 A CN 202211122619A CN 117737357 A CN117737357 A CN 117737357A
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- 229910000831 Steel Inorganic materials 0.000 title claims abstract description 172
- 239000010959 steel Substances 0.000 title claims abstract description 172
- 238000004519 manufacturing process Methods 0.000 title claims abstract description 64
- 238000000137 annealing Methods 0.000 title claims abstract description 35
- 238000001816 cooling Methods 0.000 claims abstract description 179
- 238000010438 heat treatment Methods 0.000 claims abstract description 109
- 238000002791 soaking Methods 0.000 claims abstract description 66
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims abstract description 60
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- 238000003466 welding Methods 0.000 claims abstract description 19
- 238000003303 reheating Methods 0.000 claims abstract description 17
- 230000006698 induction Effects 0.000 claims abstract description 15
- 229910000797 Ultra-high-strength steel Inorganic materials 0.000 claims abstract description 13
- 238000010583 slow cooling Methods 0.000 claims abstract description 11
- 238000007747 plating Methods 0.000 claims abstract description 8
- 238000002485 combustion reaction Methods 0.000 claims description 62
- 239000007789 gas Substances 0.000 claims description 60
- 239000002912 waste gas Substances 0.000 claims description 58
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 42
- 238000002347 injection Methods 0.000 claims description 29
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- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 2
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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
- Y02P10/25—Process efficiency
Abstract
A rapid annealing ultra-high strength strip steel production line sequentially comprises the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a transverse magnetic induction heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final air-jet cooling section and a final water-cooling section; the soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section; the rapid cooling section adopts a high-hydrogen cooling section or/and an aerosol cooling section or/and a water quenching cooling section. The invention realizes the rapid heating and rapid cooling process of high-strength steel, can produce the ultra-high-strength steel products with four different rapid cooling paths on the same production line, and produces the high-strength strip steel products with three different surface states of cold rolling annealing, acid washing and flash plating, thereby realizing the flexible production of various ultra-high-strength steel products with different surface states with low cost.
Description
Technical Field
The invention relates to the technical field of strip steel cold rolling post-treatment, in particular to a rapid continuous annealing ultra-high-strength strip steel production line.
Background
The automotive industry has become one of the pillar industries in China. Safety is a primary requirement of automobiles. In order to improve the safety of the vehicle body, the automotive material needs to have sufficient strength, and in general, the higher the material strength, the greater the absorption energy at the time of collision, and the more advantageous the safety of the vehicle body. Along with the increasing aggravation of global environment deterioration and energy shortage problems, the improvement of vehicle collision safety standards and automobile exhaust emission regulation limits in all countries in the world is added, so that the automobile weight reduction becomes one of the main development directions of the automobile manufacturing industry. Considering the manufacturing cost, recovery and maintenance of automobiles comprehensively, high-strength steel, particularly ultrahigh-strength steel, is still the first choice material for the development of the automobile industry in the future. Accordingly, the demand of the automotive industry for high strength steel strips, particularly ultra high strength steel strips, is rapidly increasing year by year. The production of continuously annealed cold-rolled ultra-high-strength strip steel is always one of the focus of each large steel mill.
Conventional continuous annealing strip processing lines typically include equipment at the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, intermediate looping, flattening, outlet looping, finishing and coiling, wherein a withdrawal and straightening station device is arranged between a flattening station and a finishing station of some treatment lines, a surface post-treatment station device such as passivation or fingerprint resistance is arranged between the flattening station and the finishing station of some treatment lines, and a withdrawal and straightening station device and a surface post-treatment station device such as passivation or fingerprint resistance are arranged between the flattening station and the finishing station of some treatment lines at the same time, as shown in figure 1.
The central continuous post-treatment station generally comprises equipment such as a common preheating section, a heating section, a soaking section, a slow cooling section, a fast cooling section, an Overaging (OA) section, a jet cooling section and a final water cooling section when producing continuously annealed cold rolled products. Some treatment lines have reheating sections arranged between the quick cooling section and the overaging section, and some units have pickling sections and reheating sections arranged between the quick cooling section and the overaging section at the same time, as shown in fig. 1.
The prior art has the following defects:
the common preheating section and the heating section of the traditional continuous annealing strip steel treatment line adopt direct fire heating, preferably adopt clean natural gas for direct fire heating, prevent unclean combustion waste gas from polluting the surface of the strip steel, and directly preheat the strip steel by utilizing the direct fire combustion waste gas. The disadvantages are:
1) The exhaust gas emission temperature of direct-fire combustion after preheating the strip steel is still relatively high, and is usually higher than 800 ℃, sometimes higher than 850 ℃, and when the exhaust gas emission temperature exceeds 850 ℃, cold air is usually doped to control the exhaust gas emission temperature to 850 ℃ or below for secondary offline utilization. The higher the exhaust gas temperature means more thermal energy is lost. According to the method, the primary online utilization rate of heat energy is low, and steam or hot water generated by secondary offline utilization cannot be completely consumed in the unit, so that the energy balance of the area is difficult; because the direct-fired waste gas directly contacts the strip steel and the contact time is longer, in addition, excessive fuel gas in the direct-fired waste gas needs to be subjected to secondary combustion in a preheating section, the secondary combustion flame is often an oxidizing flame, which necessarily limits the improvement of the preheating temperature of the strip steel, otherwise, an excessively thick oxide layer is easily formed on the surface of the strip steel, particularly for high-strength steel and ultra-high-strength steel, as the substrate is added with reinforced alloy elements such as Si, mn and the like, compared with a common strength product, the enrichment of the alloy reinforced elements is more easy to occur on the surface of the strip steel, the surface quality problem is caused, and therefore, the preheating temperature of the strip steel can only be preheated to about 250 ℃ generally, and the preheating effect is poor.
2) Some high-strength steels such as QP steel are developed and used in recent years, the annealing temperature needs to be increased to more than 900 ℃, the conventional production line cannot meet the process requirement, and the conventional radiant tube heating technology heats the strip steel in a high temperature range, so that the efficiency is low, and the energy utilization rate is very low.
3) When the thickness of the strip steel, the target annealing temperature and the unit speed are changed, the soaking temperature of the strip steel is slower in regulation speed, the temperature is limited, the thickness of the strip steel, the target annealing temperature and the unit speed are greatly changed, or the quality loss is increased due to inconsistent soaking temperature.
Disclosure of Invention
The invention aims to provide a rapid annealing ultra-high strength strip steel production line, which can realize the following purposes: when the direct fire heating is adopted, the waste heat of the waste gas generated by the direct fire combustion is fully utilized, the temperature of the strip steel can be quickly preheated to at least 350 ℃, and the waste gas generated by the direct fire combustion is prevented from directly contacting the strip steel in a preheating furnace for a long time, so that an excessively thick oxide layer is prevented from being generated on the surface of the strip steel; the waste heat of the combustion waste gas is basically transmitted to the strip steel, so that the primary utilization rate of heat energy is improved, the combustion waste gas can be directly discharged after the strip steel is fully heated, a boiler or a superheated water heating device is not required to be additionally used for secondary utilization, the investment is obviously reduced, and the occupied area is reduced. And the soaking is improved, and the quick adjustment of the soaking temperature of the strip steel is realized. Improving ultrahigh temperature heating: the transverse magnetic induction heating technology is used for further and fast improving the heating temperature of the high-temperature strip steel, realizing the ultra-high temperature annealing of the high-strength strip steel and improving the energy utilization rate. In addition, the rapid heating and rapid cooling treatment of the ultra-high strength steel is realized, and the heat treatment cycle time of the strip steel is shortened; the application of the rapid heating, rapid cooling and rapid heat treatment process technology can adopt lower alloy components to produce various advanced high-strength steel products with higher strength grades, not only can reduce the production cost of the high-strength steel, but also can improve the mechanical properties and subsequent processing properties (such as welding property and coating property) of various super-high-strength steel products, and obviously improves the market competitiveness of the high-strength steel products.
In order to achieve the above purpose, the technical scheme of the invention is as follows:
a rapid annealing ultra-high strength strip steel production line sequentially comprises the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a transverse magnetic induction heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final jet cooling section and a final water cooling section;
the soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section;
the rapid cooling section adopts a high-hydrogen cooling section or an aerosol cooling section or a water quenching cooling section;
or the high-hydrogen cooling section is arranged in parallel with the aerosol cooling section or the water quenching cooling section;
or the gas mist cooling section and the water quenching cooling section are arranged in parallel, and a connecting channel is arranged between the gas mist cooling section and the water quenching cooling section;
or the high hydrogen cooling section, the gas mist cooling section and the water quenching cooling section are arranged in parallel, a connecting channel is arranged between the gas mist cooling section and the water quenching cooling section, and the high hydrogen cooling section is connected with the reheating section.
Preferably, an optional pickling section is arranged after the final water-cooling section, and the strip steel can optionally pass through the pickling section or bypass and skip the pickling section.
Preferably, an optional flash plating section is further arranged after the acid washing section, the strip steel can be subjected to flash plating or flash plating zinc after acid washing, and the flash plating section can be skipped to directly produce acid washing surface products.
Preferably, a cleaning station is arranged between the welding station and the inlet loop station, and preferably, the cleaning stations are arranged in front of and behind the inlet loop station; the strip steel is firstly cleaned for the first time, enters the loop, is cleaned for the second time and enters the central continuous post-treatment station.
Preferably, a finishing station is arranged before the coiling station, and the strip steel is coiled after finishing.
Preferably, an intermediate loop station is arranged before the leveling station, the center of the strip steel enters the center loop after continuous post-treatment, and then enters the leveling station, so that the replacement of a working roller of the leveling machine can be realized without reducing the speed of the center continuous post-treatment.
Preferably, a withdrawal and straightening station is arranged between the flattening station and the outlet loop station, and the strip steel can be selectively withdrawn and straightened and then enter the outlet loop.
Preferably, a surface post-treatment station such as passivation or fingerprint resistance is arranged between the flattening station and the outlet loop station, and the strip steel can be subjected to surface treatment such as passivation or fingerprint resistance and then enter the outlet loop.
Preferably, a withdrawal straightening station and a surface post-treatment station such as passivation or fingerprint resistance are arranged between the flattening station and the outlet loop station, and the strip steel can be selectively subjected to withdrawal straightening or/and surface post-treatment such as passivation or fingerprint resistance and then enters the outlet loop.
In addition, the invention also provides a jet direct-fire preheating device, which comprises: a direct fire furnace and a preheating furnace; wherein,
the direct fire includes:
a furnace shell, the upper end and the lower end of which are respectively provided with a furnace top roller chamber and a furnace bottom roller chamber; steering rollers are respectively arranged in the furnace top roller chamber and the furnace bottom roller chamber; a plurality of direct-fire heating areas are arranged in the furnace shell along the height direction, and a plurality of direct-fire burners are arranged in the direct-fire heating areas; the side wall of the upper part of the furnace shell is provided with at least two through holes which are symmetrically arranged left and right;
the preheating furnace comprises:
the side wall of the upper part of the furnace body is provided with at least two connecting holes which are symmetrically arranged left and right and are respectively connected with the through holes on the upper part of the furnace shell of the direct-fired furnace through communicating pipes; the top end of the furnace body is provided with a furnace throat which corresponds to the furnace top roller chamber of the direct furnace and is used for the strip steel to pass through; the bottom of the furnace body is provided with a strip steel inlet, a corresponding sealing device and a corresponding steering roller; an upper partition plate with a through hole is arranged at the upper part in the furnace body to form an upper gas collection chamber of the direct-fire waste gas; a direct-fire combustion waste gas secondary combustion chamber is arranged below the upper gas collection chamber of the direct-fire waste gas, and at least one open-fire burner is arranged in the direct-fire combustion waste gas secondary combustion chamber; preferably, a combustion waste gas thermometer is further arranged in the direct-fired combustion waste gas secondary combustion chamber; a lower partition plate with a penetrating hole is arranged at the lower part in the furnace body to form a lower straight fire waste gas collecting chamber, and the lower straight fire waste gas collecting chamber is connected with a waste gas fan through a waste gas discharge pipeline; a control valve is arranged on the waste gas discharge pipeline;
The heat exchange and air injection bellows units are arranged on two sides below the direct-fired combustion waste gas secondary combustion chamber in the furnace body along the height direction of the furnace body, and a strip penetrating channel for strip steel to pass through is formed in the middle of the heat exchange and air injection bellows units; each heat exchange and air injection bellows unit comprises,
the air box body is vertically provided with a plurality of heat exchange tubes, and a plurality of nozzles are arranged on one side surface of the air box body, which is opposite to the threading channel; an exhaust gas secondary mixing chamber communicated with the heat exchange tube is arranged between the upper and lower bellows bodies; introducing nitrogen and hydrogen protective gas into the bellows body;
the port of the inlet pipeline of the circulating fan is arranged in the threading channel, and the port of the outlet pipeline of the circulating fan is positioned in the bellows body;
the sealing devices are respectively arranged at the upper and lower ports of the threading channel and the threading holes of the upper and lower partition plates; preferably, the sealing device is of a nitrogen sealing structure, a nitrogen sealing chamber is adopted, and a nitrogen injection pipeline is arranged on the sealing device.
In the production process, high-temperature combustion waste gas generated by direct fire combustion of a direct fire furnace enters a preheating furnace through a communicating pipe, a plurality of heat exchange and air injection bellows units which are sequentially arranged up and down are arranged in the preheating furnace, a heat exchange pipeline (high-temperature combustion waste gas tube side and protective gas tube side) of the heat exchange and air injection bellows units heats nitrogen-hydrogen mixed gas in the bellows body, high Wen Danqing mixed gas is blown to two sides of the strip steel through high-speed nozzles opposite to two sides of the strip steel, the strip steel is rapidly heated, the ejected high Wen Danqing mixed gas exchanges heat with low-temperature strip steel, the mixed gas is subjected to heat exchange again from circulating fans which are arranged close to two sides of the strip steel after the temperature of the mixed gas is reduced, the temperature of the nitrogen-hydrogen mixed gas is raised again, and then the nitrogen-hydrogen mixed gas is sprayed to two sides of the strip steel from the inside of the air injection bellows unit again, and the strip steel is circulated and reciprocated in this way.
In the preheating device:
the preheating device is characterized in that a heat exchange and air injection bellows unit and a direct-fire combustion waste gas secondary combustion chamber are arranged, the heat exchange and air injection bellows unit adopts a heat exchange pipeline (the heat exchanger is not arranged outside the furnace), the waste gas which is combusted again in the direct-fire combustion waste gas secondary combustion chamber heats nitrogen and hydrogen protective gas circularly utilized in the bellows, and the heated nitrogen and hydrogen protective gas is sprayed to the upper surface and the lower surface of the strip steel at a high speed under the action of a circulating fan for forced convection heat exchange, so that the strip steel is preheated rapidly and efficiently.
And an open flame burner is further arranged in the direct-fire combustion waste gas secondary combustion chamber and is used for carrying out oxygen-enriched secondary combustion on insufficiently combusted fuel gas in the direct-fire combustion waste gas secondary combustion chamber, and the burning flame cannot contact strip steel.
An exhaust gas secondary mixing chamber communicated with the heat exchange tube is arranged between the upper and lower bellows bodies, and the exhaust gas temperature is homogenized in the exhaust gas secondary mixing chamber and then enters the downstream bellows body.
The sealing device is of a nitrogen sealing structure and is provided with a nitrogen sealing chamber, a nitrogen injection pipeline opening is arranged in the nitrogen sealing chamber, sealing nitrogen is introduced into the nitrogen sealing chamber to maintain relatively high pressure, a large amount of direct-fire combustion waste gas is prevented from entering a strip penetrating channel in the furnace for heat exchange and the air injection bellows unit, and accordingly the surface of strip steel can be prevented from being excessively oxidized by the direct-fire combustion waste gas.
The strip steel inlet of the preheating furnace is provided with a sealing device, and the inside of the sealing device is also provided with a gas injection port for injecting a small amount of sealing nitrogen or air, so that the sealing device has the function of preventing the direct-fired combustion waste gas from overflowing out of the furnace.
The invention also provides a jet-radiation composite soaking device, which comprises:
the furnace body is internally provided with a composite heating body along the height direction; the composite heating body comprises an insulation box body, wherein an insulation material is arranged on the inner wall of the shell; a mounting hole is arranged in the center of one side surface of the heat preservation box body;
the circulating fan is arranged at the mounting hole of the heat insulation box body, the air suction inlet of the circulating fan corresponds to the axis of the mounting hole, and the air outlet is arranged on the side surface of the shell;
the buffer cavity is arranged in the insulation box body at a position corresponding to the air suction opening of the circulating fan, the back surface of the buffer cavity is provided with a hot air outlet corresponding to the air suction opening of the circulating fan, and the front surface of the buffer cavity is provided with a hot air inlet; preferably, the buffer cavity and the high-temperature air injection bellows are of an integrated structure;
the two high-temperature air jet bellows are vertically and symmetrically arranged at two sides of a hot air inlet at the front side of the buffer cavity in the heat insulation box body to form a strip penetrating channel for strip steel to pass through; a plurality of rows of jet nozzles are arranged on one side surface of the two high-temperature jet bellows at two sides of the threading channel at intervals along the height direction, and a gap is arranged between n rows of jet nozzles, wherein n is more than or equal to 1; n=1, the radiant tubes are arranged in parallel above or below the row of jet nozzles; preferably, the diameter of the jet nozzle is 1/10-1/5 of the distance from the jet nozzle to the strip steel; more preferably, the jet nozzle adopts a round hole structure;
The radiant tubes are symmetrically arranged in the two high-temperature air injection bellows and comprise a connecting tube section for connecting a burner, a radiant tube section bent and extended from one end of the connecting tube section and a heat exchange tube section formed by extending and bending from one end of the radiant tube section; the radiant tube section corresponds to gaps arranged between n rows of jet nozzles in the high-temperature jet bellows, so as to form a jet-radiation alternating structure; preferably, the radiant tube section, the connecting tube section and the heat exchange tube section of the radiant tube are arranged in parallel.
The jet-radiation composite soaking device adopts a composite heating technology, can organically combine a high-speed high-temperature jet heating technology with a radiant tube heating technology, and fully plays technical advantages of the high-speed high-temperature jet heating technology and the radiant tube heating technology. The structure of the radiant tube is optimally designed, the radiant tube is arranged in the high-speed high-temperature jet air box, heat generated by burning gas of the radiant tube is rapidly transferred to the strip steel through two modes of high-speed high-temperature jet and radiation, the rapid heating of the strip steel is realized, the highest average heating speed of the strip steel of 1mm is not lower than 40 ℃/s, the length of a heating furnace can be greatly shortened, the heating section of a unit with 30 ten thousand tons per year output is about 2 pass, and the thermal inertia of a furnace body is reduced;
Second, heat generated by the fuel gas is transferred to the circulating gas (N 2 +H 2 ) The heat-conducting material is taken away, so that the exhaust temperature of the radiant tube can be reduced, the exhaust temperature of the radiant tube can be reduced by about 100 ℃ under the same condition, the heat efficiency of the radiant tube is improved by about 5%, the average working temperature of the radiant tube can be reduced, and the service life of the radiant tube is prolonged;
and the temperature of the heated circulating gas is uniform, so that the temperature distribution of the strip steel in the width direction in the heating process is uniform, and the temperature distribution of the strip steel in the width direction in the actual heating process is controlled to be +/-5 ℃ according to the uniformity of the strip steel in the width direction, thereby realizing the stable operation of the unit. The high-speed air injection and radiation composite heating technology can obviously improve the productivity of the existing unit and solve the problem of insufficient heating capacity on the production line.
The radiant tube of the jet-radiation composite soaking device has the functions of combustion radiation (namely, the high-temperature section of the radiant tube between two rows of nozzles) and a heat exchanger, and is used for heating circulating gas, so that the heat of the combustion gas in the radiant tube can be rapidly transferred to strip steel through forced heat exchange, the rapid heating of the strip steel is realized, the length of a heating furnace can be greatly shortened, and the thermal inertia of a large-scale vertical continuous annealing furnace body is reduced.
The production line of the invention is different from the traditional continuous heat treatment line in the following points or innovation points:
1) When the direct fire heating is used, the jet direct fire preheating section is used for replacing the common preheating section, and the obvious characteristics of the jet direct fire preheating section are that:
(1) the method has the advantages that compared with the traditional preheating method, the heat loss of a furnace shell and a protective gas channel is obviously reduced, the waste heat utilization of combustion waste gas is more complete, the heating efficiency is higher, and the heating rate is faster;
(2) in the jet direct-fire preheating section, the combustion waste gas of the heating section passes through a heat exchanger chamber of the preheating section, and in the passing process, the combustion waste gas of the heating section and a heat exchanger in the heat exchanger chamber perform sufficient heat exchange to heat the nitrogen-hydrogen protective gas, so that the combustion waste gas of the heating section is not always in direct contact with strip steel in the jet direct-fire preheating section (when the heating section adopts direct-fire heating, the jet direct-fire preheating section is only in short time in a high-temperature section and the waste gas belongs to a reducing atmosphere or a micro-oxidation atmosphere at the moment), thereby avoiding the surface peroxidation of the strip steel;
(3) When the heating section adopts direct fire heating, insufficiently combusted fuel gas in the direct fire combustion waste gas is subjected to oxygen-enriched secondary combustion in a semi-sealing unit at the top of the air injection preheating section, but the combusting flame does not contact strip steel, so that the surface peroxidation of the strip steel is effectively avoided;
(4) the preheating temperature of the strip steel is higher, and when the heating section adopts direct fire heating, the high-temperature nitrogen-hydrogen protective gas is sprayed to have high direct fire preheating heat exchange coefficient, so that the temperature of the preheated strip steel at least can reach 350 ℃ or above, and is at least 100 ℃ higher than that of the strip steel in the common preheating section;
(5) when the heating section adopts direct fire heating, the temperature of the direct fire combustion exhaust gas from the jet direct fire preheating section is usually far lower than 750 ℃ (if the number of the high-speed jet preheating units is enough, the direct discharge can be even lower than 200 ℃), and the secondary utilization outside the furnace or the secondary utilization at all is not required by the cold air.
2) The rapid heating and rapid cooling annealing treatment of the high-strength steel is realized by the cooperation of the direct-fire heating equipment, the transverse magnetic induction heating equipment and the high-hydrogen rapid cooling equipment, so that the strength of the high-strength steel can be improved;
3) The transverse magnetic induction heating is used for further rapid promotion of the height Wen Daigang, so that the ultra-high temperature annealing of the high-strength steel can be realized;
4) The soaking section adopts the jet-radiation composite soaking section to realize the rapid adjustment of the soaking temperature of the strip steel when the working conditions such as the thickness specification change, the target temperature change, the unit speed change and the like of the strip steel are changed.
5) The technical scheme of the invention can also realize continuous production of the ultra-high-strength steel with three different surface states of cold rolling annealing, acid washing and flash plating.
The invention has the beneficial effects that:
1) The temperature of the strip steel after preheating is high, and the primary utilization rate of heat energy is high;
2) The invention realizes the rapid heating and cooling treatment of the strip steel and can produce strip steel products with high strength level;
3) When the jet-radiation composite soaking is adopted, the soaking temperature of the strip steel can be quickly adjusted when the working conditions such as the thickness specification of the strip steel is changed, the target temperature is changed, the speed of a unit is changed and the like are changed, and the quality loss caused by inconsistent strip steel temperature can be reduced;
4) The application of the rapid heating, rapid cooling and rapid heat treatment process technology can adopt lower alloy components to produce various advanced high-strength steel products with higher strength grades, the components of 450 MPa-grade products can reach the strength of 590 MPa-grade products, the components of 780 MPa-grade products can reach the performance of 980 MPa-grade products correspondingly, the production cost of the high-strength steel can be reduced, the mechanical properties and the subsequent processing properties (such as welding property and coating property) of various super-high-strength steel products can be improved, and the market competitiveness of the high-strength steel products is obviously improved;
5) The invention realizes the rapid heating and cooling treatment of the ultra-high strength steel and shortens the heat treatment cycle time of the strip steel;
6) The technical scheme of the invention can realize continuous production of the ultra-high-strength steel with three different surface states of cold rolling annealing, acid washing and flash plating.
Drawings
FIG. 1 is a schematic diagram of a station arrangement of a conventional continuous annealing production line;
FIG. 2 is a layout of the production line in accordance with embodiment 1 of the present invention;
FIG. 3 is a layout of the production line in accordance with embodiment 2 of the present invention;
FIG. 4 is a station layout of the production line of example 3 of the present invention;
FIG. 5 is a station layout of the production line of example 4 of the present invention;
FIG. 6 is a layout of the production line of embodiment 5 of the present invention;
FIG. 7 is a layout of the production line of embodiment 6 of the present invention;
FIG. 8 is a station layout of the production line of example 7 of the present invention;
FIG. 9 is a schematic view of an embodiment of a jet direct-fire preheating device according to the present invention;
FIG. 10 is a schematic view of a preheating furnace in an embodiment of the jet direct-fire preheating device according to the present invention;
FIG. 11 is a schematic view of a schematic structure 1 of an embodiment of a jet-propelled radiant composite soaking device according to the present invention;
fig. 12 is a schematic structural view 2 of an embodiment of a jet-radiation composite soaking device according to the present invention;
Fig. 13 is a schematic structural diagram of a composite heating body in an embodiment of the jet-propelled radiation composite soaking device according to the present invention;
FIG. 14 is a partial perspective view of a high temperature jet bellows in an embodiment of a jet-radiant composite soaking apparatus according to the present invention;
fig. 15 is a perspective view of a radiant tube in an embodiment of the jet-propelled radiant composite soaking device according to the present invention.
Detailed Description
The invention is further illustrated by the following examples and figures: it should be noted that, by applying the inventive concept, various production lines can be derived and expanded, only some embodiments are given in this example, and other embodiments are given in the present invention, even if all the group patent examples are given only some embodiments, various combinations generated by selecting or not selecting the optional stations or segments according to the inventive concept are within the scope of the present invention, and various production lines derived according to the inventive concept are also within the scope of the present invention. In addition, for conventional stations, such as cleaning stations comprising an alkali liquor spraying section, an alkali liquor brushing section, an electrolytic cleaning section, a hot water brushing or cold water abrasive particle roller brushing section and a hot water rinsing section, even the cleaning new technical equipment which is simplified and combined by adopting a high-pressure water jet brushing section, an ultrasonic cleaning section, a high-pressure cleaning section and the like is considered to be the production line of the invention, and the production line is also within the protection scope of the invention. As another example, finishing stations including trimming, oiling, etc., are also within the scope of the present invention.
Referring to fig. 2, in embodiment 1 of the present invention, the rapid annealing ultra-high strength strip steel production line sequentially includes the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a transverse magnetic induction heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final jet cooling section and a final water cooling section;
the soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section;
the rapid cooling section adopts a high-hydrogen cooling section;
in the production line, a jet direct fire preheating section, a transverse magnetic induction heating section and a high-hydrogen cooling section are adopted to carry out rapid heating and rapid cooling treatment, so that the continuous production of the ultra-high-strength strip steel is realized.
Referring to fig. 3, an embodiment 2 of the present invention is shown, in the embodiment 2, the rapid annealing ultra-high strength strip steel production line sequentially includes the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final jet cooling section and a final water cooling section;
The soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section;
the rapid cooling section adopts an aerosol cooling section.
Referring to fig. 4, an embodiment 3 of the present invention is shown, and in embodiment 3, the rapid annealing ultra-high strength strip steel production line sequentially includes the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final jet cooling section and a final water cooling section;
the soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section;
the rapid cooling section adopts a water quenching cooling section.
Referring to fig. 5, an embodiment 4 of the present invention is shown, and in the embodiment 4, the rapid annealing ultra-high strength strip steel production line sequentially includes the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final jet cooling section and a final water cooling section;
The soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section;
the rapid cooling section adopts a high-hydrogen cooling section and an aerosol cooling section which are arranged in parallel, and the strip steel can be selectively moved away from the high-hydrogen cooling section to perform high-hydrogen cooling and can also be selectively moved away from the aerosol cooling section to perform aerosol cooling.
The production line can adopt a jet direct fire preheating section, a high hydrogen cooling section and an aerosol cooling section simultaneously to carry out rapid heating and optional rapid cooling treatment, thereby realizing the continuous production of the ultra-high strength strip steel.
Referring to fig. 6, an embodiment 5 of the present invention is shown, and in the embodiment 5, the rapid annealing ultra-high strength strip steel production line of the present invention includes the following stations in order: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final jet cooling section and a final water cooling section;
the soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section;
the rapid cooling section is arranged in parallel by adopting a high-hydrogen cooling section and a water quenching cooling section, and the strip steel can be selectively cooled by the high-hydrogen cooling section or the water quenching cooling section.
In the production line, a jet direct fire preheating section, a high hydrogen cooling section and a water quenching cooling section are adopted simultaneously to carry out rapid heating and optional rapid cooling treatment, so that the continuous production of the ultra-high-strength strip steel is realized.
Referring to fig. 7, an embodiment 6 of the present invention is shown, and in the embodiment 6, the rapid annealing ultra-high strength strip steel production line of the present invention includes the following stations in order: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final jet cooling section and a final water cooling section;
the soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section;
the rapid cooling section adopts an aerosol cooling section and a water quenching cooling section which are arranged in parallel, and a connecting channel is arranged between the aerosol cooling section and the water quenching cooling section, so that three rapid cooling modes of the strip steel, namely the aerosol cooling section and the water quenching cooling section, or only the aerosol cooling section or only the water quenching cooling section, are formed.
The rapid cooling section adopts an aerosol cooling section and a water quenching cooling section;
In the production line, a jet direct fire preheating section, an aerosol cooling section and a water quenching cooling section are adopted simultaneously to carry out rapid heating and optional rapid cooling treatment, so that the continuous production of the ultra-high-strength strip steel is realized.
Referring to fig. 8, an embodiment 7 of the present invention is shown, and in the embodiment 7, the rapid annealing ultra-high strength strip steel production line of the present invention includes the following stations in order: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final jet cooling section and a final water cooling section;
the soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section;
the rapid cooling section further comprises a high-hydrogen cooling section which is arranged in parallel with the gas mist cooling section and the water quenching cooling section, and the gas mist cooling section and the water quenching cooling section are arranged in series to form four rapid cooling modes, namely, only the high-hydrogen cooling section, only the gas mist cooling section, only the water quenching cooling section, or only the gas mist cooling section and then the water quenching cooling section.
The strip steel can be cooled by aerosol cooling and then water quenching, or can be cooled by aerosol cooling or water quenching; the Gao Qingleng cooling sections are arranged in parallel with the (aerosol cooling section and the water quenching cooling section), and the strip steel can be selected to be subjected to high-hydrogen cooling section or to rapid cooling treatment by the aerosol cooling section and the water quenching cooling section.
In the production line, a jet direct fire preheating section, a high hydrogen cooling section and a (aerosol cooling section and water quenching cooling section) are adopted simultaneously to carry out rapid heating and optional rapid cooling treatment, so that the continuous production of the ultra-high-strength strip steel is realized.
Referring to fig. 9 and 10, the injection direct-fire preheating device according to the present invention includes: a direct burner 1 and a preheating furnace 2; wherein,
the direct burner 1 comprises:
a furnace shell 11, the upper and lower ends of which are respectively provided with a furnace top roller chamber 101 and a furnace bottom roller chamber 102; the furnace top roller chamber 101 and the furnace bottom roller chamber 102 are respectively provided with steering rollers 12 and 12'; a plurality of direct-fire heating areas 111 are arranged in the furnace shell 11 along the height direction, and a plurality of direct-fire burners 13 are arranged in the direct-fire heating areas 111; the side wall of the upper part of the furnace shell 11 is provided with two through holes which are symmetrically arranged left and right;
the preheating furnace 2 includes:
the furnace body 21 is provided with two connecting holes on the side wall of the upper part, is symmetrically arranged left and right, and is respectively connected with the through holes on the upper part of the furnace shell 11 of the direct-fired furnace 1 through the communicating pipe 22; the top end of the furnace body 21 is provided with a furnace throat 211 which corresponds to the furnace top roller chamber 101 of the direct furnace 1 and is used for the strip steel to pass through; the bottom of the furnace body 21 is provided with a strip steel inlet and a corresponding sealing device 212 and a steering roller 23; an upper partition plate 213 with a through hole is arranged at the upper part in the furnace body 21 to form a direct-fire waste gas upper gas collection chamber 201; a direct-fire combustion waste gas secondary combustion chamber 202 is arranged below the direct-fire waste gas upper gas collection chamber 201, and at least one open-fire burner 24 is arranged in the direct-fire combustion waste gas secondary combustion chamber 202; a lower partition plate 214 with a penetrating hole is arranged at the lower part in the furnace body 21 to form a lower straight fire waste gas collecting chamber 203, and is connected with a waste gas fan 25 through a waste gas discharge pipeline 215 to be discharged from a chimney 500;
A plurality of heat exchange and air injection bellows units 26 which are arranged at two sides below the direct-fire combustion waste gas secondary combustion chamber 202 in the furnace body 21 along the height direction of the furnace body 21, and a penetrating channel 204 for the strip steel to pass through is formed in the middle; each heat exchange and air injection bellows unit 26 includes,
a bellows body 261, in which a plurality of heat exchange tubes 262 are vertically arranged, and a plurality of nozzles 263 are arranged on one side surface of the bellows body 261 opposite to the threading channel 204; an exhaust gas secondary mixing chamber 205 communicated with the heat exchange tube 262 is arranged between the upper and lower bellows bodies 261; introducing nitrogen and hydrogen protective gas into the bellows 261;
a circulating fan 264, the inlet of which is arranged in the threading channel 204, and the outlet of which is arranged in the bellows 261;
a plurality of sealing devices 27, 27', 27″ for the strip steel to pass through are respectively arranged at the upper and lower ports of the strip passing channel 204 and at the strip passing holes of the upper and lower partition plates 213, 214.
Preferably, a combustion exhaust gas thermometer 28 is also disposed in the direct-fired combustion exhaust gas secondary combustion chamber 202.
Preferably, the sealing devices 27, 27', 27″ are nitrogen sealing structures, and nitrogen sealing chambers are adopted, on which nitrogen injection pipelines are arranged.
Preferably, a control valve 216 is provided on the exhaust gas discharge pipe 215.
The strip steel 100 is turned to upwards run by a turning roll in front of the direct fire furnace, enters the preheating furnace 2 for preheating after being sealed by a preheating furnace inlet sealing device, then enters a furnace top roll chamber of the direct fire furnace 1 for direct fire heating after being turned by the turning roll, then enters a furnace bottom roll chamber of the direct fire furnace 1 for continuous running after being turned by the turning roll.
The temperature of the waste gas is reduced after the nitrogen-hydrogen protective gas is heated by the direct-fire combustion waste gas through the heat exchange pipeline (the nitrogen-hydrogen protective gas is blown to the upper surface and the lower surface of the strip steel to preheat the strip steel under the action of the circulating fan), and the nitrogen-hydrogen protective gas after the temperature reduction is sucked into the bellows by the circulating fan 264 on the two sides of the working side (WS side) and the driving side (DS side) of the preheating furnace to exchange heat with the heat exchange pipeline; the direct-fired combustion exhaust gas sequentially passes through the heat exchange and air injection bellows unit from top to bottom, is sucked by the (variable frequency) exhaust gas fan 25, passes through the exhaust gas discharge pipeline 215, passes through the waste heat boiler 400 to carry out secondary utilization of the waste heat of the combustion exhaust gas, and then enters the chimney 500 to be finally discharged.
Referring to fig. 11 to 15, the jet-radiation composite soaking device according to the present invention includes:
a furnace body 4 in which a composite heating body 5 is arranged in the height direction; the composite heating body 5 comprises a metal sheet and a metal sheet,
A heat-insulating box 51, the inner wall of which is provided with a heat-insulating material; a mounting hole is arranged in the center of one side surface of the heat preservation box body 51;
the circulating fan 52 is arranged at the mounting hole of the heat insulation box body 51, the air suction inlet 521 of the circulating fan corresponds to the axis of the mounting hole, and the air outlet 522 is arranged on the side surface of the casing;
the buffer cavity 53 is arranged in the insulation box 51 at a position corresponding to the air suction opening of the circulating fan 52, the back surface of the buffer cavity 53 is provided with a hot air outlet corresponding to the air suction opening of the circulating fan 52, and the front surface of the buffer cavity is provided with a hot air inlet;
the two high-temperature air jet bellows 54, 54' are vertically and symmetrically arranged at two sides of the hot air inlet at the front side of the buffer cavity 53 in the heat insulation box body 51 to form a strip penetrating channel 200 for the strip 100 to penetrate through; a plurality of rows of jet nozzles 55, 55 'are arranged on one side surface of the two high-temperature jet bellows 54, 54' positioned on two sides of the threading channel 100 at intervals along the height direction, and a gap 300 is arranged between n rows of jet nozzles, wherein n is more than or equal to 1;
the plurality of radiant tubes 56, 56 'are symmetrically arranged in the two high-temperature jet bellows 54, 54', and the radiant tubes 56 (radiant tubes 56 are exemplified by the same below) comprise a connecting tube section 561 for connecting with a burner, a radiant tube section 562 which is bent and extended from one end of the connecting tube section 561, and a heat exchange tube section 563 which is formed by extending and bending from one end of the radiant tube section 562; the radiant tube sections 562 correspond to the gaps 300 provided between the n rows of jet nozzles in the high temperature jet bellows 54 to form an alternating jet and radiant configuration.
Preferably, the buffer cavity and the high-temperature air injection bellows are of an integrated structure.
Preferably, the diameter of the jet nozzle is 1/10-1/5 of the distance from the jet nozzle to the strip steel.
Preferably, the jet nozzle adopts a round hole structure.
Preferably, the radiant tube adopts a space four-stroke structure to form four sections of tube sections which are arranged in parallel, wherein one of the tube sections is a radiant tube section, and the rest is a connecting tube section and a heat exchange tube section.
Example 1
A high-strength strip steel is prepared, the production line is arranged as shown in figure 2, the strip steel is uncoiled, welded, an inlet loop passes through and is cleaned, then, the strip steel is sprayed with direct fire to be preheated to 355 ℃, then, a radiant tube is heated to 810 ℃, then, the transverse magnetic induction is heated to 910 ℃, then, the strip steel is subjected to air-jet radiation composite soaking for 60 seconds at 910 ℃, the strip steel is slowly cooled to 700 ℃, then the strip steel is subjected to high-hydrogen cooling to 320 ℃, then, overaging treatment is carried out at 320 ℃ (reheating is not needed), the strip steel is finally subjected to air-jet cooling to about 140 ℃ and finally is subjected to water cooling to room temperature, then, the strip steel is flattened and then enters an outlet loop, and finally is coiled, so that the production is completed.
Example 2
A high-strength strip steel is prepared, the production line arrangement of the high-strength strip steel is shown in fig. 3, and the main chemical components (mass%) of the substrate are: uncoiling, welding, passing an inlet loop and cleaning strip steel with 0.10-0.23% of C and 2.1% of Mn, spraying direct fire, preheating to 360 ℃, heating to 660 ℃ by direct fire, heating to 830 ℃ by a radiant tube, heating to 930 ℃ by transverse magnetic induction, soaking the radiant tube at 930 ℃ for 50 seconds, slowly cooling to 750 ℃, cooling to 300 ℃ by aerosol, performing overaging treatment (reheating is not needed), finally cooling to 140 ℃ by air injection, finally cooling to room temperature by water, performing pickling treatment, flattening, entering an outlet loop, and finally coiling to finish production. The final product band steel has yield strength of 972MPa, tensile strength 1196MPa and elongation at break of 11%.
Example 3
A high-strength strip steel is prepared, the production line arrangement is shown in figure 4, after strip steel uncoiling, welding, entrance loop passing and cleaning, the strip steel is sprayed with direct fire to be preheated to 375 ℃, then the strip steel is sprayed with direct fire to be heated to 635 ℃, then a radiant tube is heated to 800 ℃, then transverse magnetic induction is heated to 850 ℃, then the strip steel is subjected to air-jet radiation composite soaking for 70 seconds at 850 ℃, then the strip steel is slowly cooled to 740 ℃, then water quenched to be cooled to about 50 ℃, then the strip steel is heated to 320 ℃, then overaging treatment is carried out at 320 ℃, finally air-jet cooling is carried out to about 140 ℃, finally water cooling is carried out to room temperature, then the strip steel is flattened, and finally the strip steel enters into an exit loop, and is coiled, thus the production is completed.
Example 4
A high-strength strip steel is prepared, the production line arrangement of the high-strength strip steel is shown in fig. 5, and the main chemical components (mass%) of the substrate are as follows: uncoiling, welding, passing through an inlet loop and cleaning strip steel with 0.09-0.013% of C and 0.87% of Mn, spraying direct fire to preheat to 370 ℃, heating to 700 ℃ by direct fire, heating to 800 ℃ by a radiant tube, heating to 850 ℃ by transverse magnetic induction, carrying out air jet radiation composite soaking for 50 seconds at 850 ℃, slowly cooling to 670 ℃, selecting high-hydrogen cooling, or selecting aerosol cooling, selecting high-hydrogen air jet to cool to about 230 ℃, then entering an overaging section (reheating without input), carrying out overaging treatment, finally carrying out air jet cooling to about 140 ℃, finally carrying out water cooling to room temperature, flattening, entering an outlet loop, and finally coiling to finish production. The final product band steel has the yield strength of 476MPa, the tensile strength of 556MPa and the breaking elongation of 24 percent.
Example 5
A high-strength strip steel is prepared, the production line is arranged as shown in figure 6, the strip steel is uncoiled, welded, an inlet loop passes through and is cleaned, then is sprayed with direct fire to be preheated to 358 ℃, then is heated to 690 ℃, then is heated to 790 ℃ by a radiant tube, finally is heated to 890 ℃ by transverse magnetic induction, is subjected to air-jet radiation composite soaking for 50 seconds at 890 ℃, is slowly cooled to 670 ℃, high-hydrogen cooling can be selected at the moment, water quenching cooling can also be selected, the water quenching cooling is selected to room temperature, then is heated to 280 ℃, then enters an overaging section to be subjected to overaging treatment at 280 ℃, is finally subjected to air-jet cooling to about 140 ℃, enters an outlet loop after being flattened, and is finally coiled, so that the production is completed.
Example 6
A high-strength strip steel is prepared, the production line arrangement of which is shown in fig. 7, and the main chemical components (mass%) of the substrate are: uncoiling, welding, passing an inlet loop and cleaning strip steel with 0.10-0.18% of C and 2.0% of Mn, spraying direct fire to preheat to 365 ℃, heating to 665 ℃ by direct fire, heating to 820 ℃ by a radiant tube, heating to 920 ℃ by transverse magnetic induction, soaking the radiant tube at 920 ℃ for 60 seconds, slowly cooling to 750 ℃, selecting aerosol cooling, or selecting water quenching, or selecting first aerosol cooling and then water quenching, wherein the strip steel of the embodiment is firstly aerosol cooled to 500 ℃, then water quenched to about 50 ℃, then heated to 230 ℃ for overaging treatment, finally air-jet cooled to about 140 ℃ and finally water-cooled to room temperature, then flattening, entering the outlet loop, and finally coiling to finish production. The yield strength of the final product strip steel is 956MPa, the tensile strength is 1183MPa, and the elongation at break is 13%.
Example 7
A high-strength strip steel is prepared, the production line is arranged as shown in figure 8, the strip steel is uncoiled, welded, an inlet loop passes through and is cleaned, then sprayed with direct fire to be preheated to 395 ℃, then the radiation tube is heated to 800 ℃, then the transverse magnetic induction is heated to 890 ℃, then the air-jet radiation is compositely soaked for 60 seconds at 890 ℃, the temperature is slowly cooled to 750 ℃, high-hydrogen cooling can be selected, air mist cooling can also be selected, water quenching cooling can also be selected, air mist cooling can also be selected, then water quenching cooling can be performed, the strip steel in the embodiment is selected, the air mist cooling is performed to about 50 ℃, then the strip steel is heated to 260 ℃ for overaging treatment, finally the air-jet cooling is performed to about 140 ℃, the strip steel is finally cooled to room temperature, then the strip steel is leveled, the strip steel enters into the outlet loop, and finally coiled, and the production is completed.
Claims (9)
1. The rapid annealing ultra-high strength strip steel production line is characterized by sequentially comprising the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, flattening, outlet looping and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet direct-fire preheating section, a direct-fire heating section, a radiant tube heating section, a transverse magnetic induction heating section, a soaking section, a slow cooling section, a rapid cooling section, a reheating section, an overaging section, a final jet cooling section and a final water cooling section;
The soaking section adopts a radiant tube soaking section or a jet-radiation composite soaking section;
the rapid cooling section adopts a high-hydrogen cooling section or an aerosol cooling section or a water quenching cooling section;
or the high-hydrogen cooling section is arranged in parallel with the aerosol cooling section or the water quenching cooling section;
or the gas mist cooling section and the water quenching cooling section are arranged in parallel, and a connecting channel is arranged between the gas mist cooling section and the water quenching cooling section;
or the high hydrogen cooling section, the gas mist cooling section and the water quenching cooling section are arranged in parallel, a connecting channel is arranged between the gas mist cooling section and the water quenching cooling section, and the high hydrogen cooling section is connected with the reheating section.
2. The rapid annealing ultra-high strength strip steel production line according to claim 1, wherein an optional pickling section is arranged after the final water-cooling section, and the strip steel can optionally pass through the pickling section or bypass and skip the pickling section.
3. The rapid annealing ultra-high strength strip steel production line of claim 2, wherein an optional flash plating section is further provided after the pickling section.
4. A rapid annealing ultra high strength steel strip production line according to any one of claims 1 to 3, wherein a cleaning station is provided between the welding station and the inlet looping station, preferably before and after the inlet looping station.
5. The rapid annealing ultra-high strength strip steel production line according to any one of claims 1 to 4, wherein a finishing station is provided before the coiling station.
6. The rapid annealing ultra high strength steel strip production line according to any one of claims 1 to 5, wherein an intermediate looper station is provided before the flattening station.
7. The rapid annealing ultra-high strength strip steel production line according to any one of claims 1 to 6, wherein a withdrawal and straightening station is provided between the flattening station and the outlet looper station; or, a passivation or fingerprint-resistant surface post-treatment station is arranged between the leveling station and the outlet looper station; or a withdrawal straightening station and a surface post-treatment station such as passivation or fingerprint resistance are arranged between the flattening station and the outlet looper station.
8. A jet direct fire preheating device for a rapid annealing ultra high strength steel strip production line according to any one of claims 1 to 7, comprising: a direct fire furnace and a preheating furnace; wherein,
the direct fire includes:
a furnace shell, the upper end and the lower end of which are respectively provided with a furnace top roller chamber and a furnace bottom roller chamber; steering rollers are respectively arranged in the furnace top roller chamber and the furnace bottom roller chamber; a plurality of direct-fire heating areas are arranged in the furnace shell along the height direction, and a plurality of direct-fire burners are arranged in the direct-fire heating areas; the side wall of the upper part of the furnace shell is provided with at least two through holes which are symmetrically arranged left and right;
The preheating furnace comprises:
the side wall of the upper part of the furnace body is provided with at least two connecting holes which are symmetrically arranged left and right and are respectively connected with the through holes on the upper part of the furnace shell of the direct-fired furnace through communicating pipes; the top end of the furnace body is provided with a furnace throat which corresponds to the furnace top roller chamber of the direct furnace and is used for the strip steel to pass through; the bottom of the furnace body is provided with a strip steel inlet, a corresponding sealing device and a corresponding steering roller; an upper partition plate with a through hole is arranged at the upper part in the furnace body to form an upper gas collection chamber of the direct-fire waste gas; a direct-fire combustion waste gas secondary combustion chamber is arranged below the upper gas collection chamber of the direct-fire waste gas, and at least one open-fire burner is arranged in the direct-fire combustion waste gas secondary combustion chamber; preferably, a combustion waste gas thermometer is further arranged in the direct-fired combustion waste gas secondary combustion chamber; a lower partition plate with a penetrating hole is arranged at the lower part in the furnace body to form a lower straight fire waste gas collecting chamber, and the lower straight fire waste gas collecting chamber is connected with a waste gas fan through a waste gas discharge pipeline; a control valve is arranged on the waste gas discharge pipeline;
the heat exchange and air injection bellows units are arranged on two sides below the direct-fired combustion waste gas secondary combustion chamber in the furnace body along the height direction of the furnace body, and a strip penetrating channel for strip steel to pass through is formed in the middle of the heat exchange and air injection bellows units; each heat exchange and air injection bellows unit comprises,
the air box body is vertically provided with a plurality of heat exchange tubes, and a plurality of nozzles are arranged on one side surface of the air box body, which is opposite to the threading channel; an exhaust gas secondary mixing chamber communicated with the heat exchange tube is arranged between the upper and lower bellows bodies; introducing nitrogen and hydrogen protective gas into the bellows body;
The port of the inlet pipeline of the circulating fan is arranged in the threading channel, and the port of the outlet pipeline of the circulating fan is positioned in the bellows body;
the sealing devices are respectively arranged at the upper and lower ports of the threading channel and the threading holes of the upper and lower partition plates; preferably, the sealing device is of a nitrogen sealing structure, a nitrogen sealing chamber is adopted, and a nitrogen injection pipeline is arranged on the sealing device.
9. A jet-radiation composite soaking apparatus for a rapid annealing ultra-high-strength steel strip production line according to any one of claims 1 to 7, comprising:
the furnace body is internally provided with a composite heating body along the height direction; the composite heating body comprises a plurality of heating elements,
the inner wall of the shell of the heat preservation box body is provided with a heat preservation material; a mounting hole is arranged in the center of one side surface of the heat preservation box body;
the circulating fan is arranged at the mounting hole of the heat insulation box body, the air suction inlet of the circulating fan corresponds to the axis of the mounting hole, and the air outlet is arranged on the side surface of the shell;
the buffer cavity is arranged in the insulation box body at a position corresponding to the air suction opening of the circulating fan, the back surface of the buffer cavity is provided with a hot air outlet corresponding to the air suction opening of the circulating fan, and the front surface of the buffer cavity is provided with a hot air inlet; preferably, the buffer cavity and the high-temperature air injection bellows are of an integrated structure;
The two high-temperature air jet bellows are vertically and symmetrically arranged at two sides of a hot air inlet at the front side of the buffer cavity in the heat insulation box body to form a strip penetrating channel for strip steel to pass through; a plurality of rows of jet nozzles are arranged on one side surface of the two high-temperature jet bellows at two sides of the threading channel at intervals along the height direction, and a gap is arranged between n rows of jet nozzles, wherein n is more than or equal to 1; preferably, the diameter of the jet nozzle is 1/10-1/5 of the distance from the jet nozzle to the strip steel; more preferably, the jet nozzle adopts a round hole structure;
the radiant tubes are symmetrically arranged in the two high-temperature air injection bellows and comprise a connecting tube section for connecting a burner, a radiant tube section bent and extended from one end of the connecting tube section and a heat exchange tube section formed by extending and bending from one end of the radiant tube section; the radiant tube section corresponds to gaps arranged between n rows of jet nozzles in the high-temperature jet bellows, so as to form a jet-radiation alternating structure; preferably, the radiant tube section, the connecting tube section and the heat exchange tube section of the radiant tube are arranged in parallel.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211122619.0A CN117737357A (en) | 2022-09-15 | 2022-09-15 | Quick continuous annealing ultra-high strength strip steel production line |
| PCT/CN2023/119209 WO2024056085A1 (en) | 2022-09-15 | 2023-09-15 | Rapid heat treatment production line of strip steel |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211122619.0A CN117737357A (en) | 2022-09-15 | 2022-09-15 | Quick continuous annealing ultra-high strength strip steel production line |
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