CN117737398A - Flexible post-treatment line suitable for producing various ultra-high-strength strip steels - Google Patents
Flexible post-treatment line suitable for producing various ultra-high-strength strip steels Download PDFInfo
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- CN117737398A CN117737398A CN202211122521.5A CN202211122521A CN117737398A CN 117737398 A CN117737398 A CN 117737398A CN 202211122521 A CN202211122521 A CN 202211122521A CN 117737398 A CN117737398 A CN 117737398A
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- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Abstract
A flexible post-treatment line suitable for producing various ultra-high strength strip steels sequentially comprises the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, intermediate looping, flattening, outlet looping, finishing and coiling; the central continuous post-treatment station sequentially comprises a jet radiant tube preheating section, a radiant tube heating section, a transverse magnetic induction heating section or a jet radiant composite heating section, a radiant tube soaking section, a slow cooling section, a rapid cooling section, a reheating section, a parallel-connection (a furnace nose section, a zinc pot section, an air knife section, an alloying heating section, an alloying soaking section and a post-plating cooling section), a moving channel section, an overaging section and a final jet cooling section), a final water cooling section and an optionally arranged pickling section and a flash plating section. The flexible post-treatment line has more than three selectable process paths, and can realize the production of five different types of high-strength steel including cold rolling annealing, acid washing, flash plating, hot dip pure zinc and alloying hot dip galvanizing.
Description
Technical Field
The invention relates to a strip steel cold rolling post-treatment technology, in particular to a flexible post-treatment line suitable for producing various ultra-high strength strip steels.
Background
Energy conservation and emission reduction are the necessary trend of the development of the automobile industry. The energy conservation and the reduction of the automobile industry exclude measures for improving the fuel economy, such as improving the engine efficiency, the transmission system efficiency, the automobile windage and the like, and the light weight is an indispensable means. In light weight, the use of high strength steel and ultra high strength steel remains the preferred option for automotive plants. Accordingly, in recent years, demand for high-strength steel strips, particularly ultra-high-strength steel strips, including continuously annealed cold-rolled steel strips, hot-dip galvanized steel strips (hereinafter abbreviated as GI) and galvannealed steel strips (hereinafter abbreviated as GA), has increased year by year.
Conventional strip processing lines, in addition to each looper station apparatus, typically include the following stations: uncoiling, welding, cleaning, central continuous post-treatment, flattening, finishing and coiling, wherein a withdrawal and straightening station is further arranged between a flattening station and a finishing station on some treatment lines, a post-treatment station is arranged between the flattening station and the finishing station on some treatment lines, and a withdrawal and straightening station and a post-treatment station are simultaneously arranged between the flattening station and the finishing station on other treatment lines.
The above-mentioned central continuous post-treatment station generally comprises the equipment of a general preheating section-heating section-soaking section-slow cooling section-fast cooling section-Overaging (OA) section-air-jet cooling section and final water-cooling section when producing continuously annealed cold rolled products, as shown in fig. 1. And a reheating section is arranged between the quick cooling section and the overaging section, and an acid washing section and a reheating section are simultaneously arranged between the quick cooling section and the overaging section by using other units. In the production of GI products, the central continuous post-treatment station typically comprises in sequence the equipment of a common preheating section-heating section-soaking section-slow cooling section-fast cooling section-balanced heat preservation section-furnace nose section-zinc pot section-air knife section-post-plating cooling section-final water cooling section, as shown in fig. 2. And a reheating section is arranged between the quick cooling section and the balanced heat preservation section, and an acid washing section and a reheating section are simultaneously arranged between the quick cooling section and the balanced heat preservation section by using other units. There are treatment lines with a movable post-plating quick-cooling section arranged within 10 meters above the air knife between the air knife section and the fixed post-plating cooling section (typically in the upper half of the APC tower). In the production of GA products, the central continuous post-treatment station typically comprises in sequence the equipment of a common preheating section-heating section-soaking section-slow cooling section-fast cooling section-balanced heat-preserving section-furnace nose section-zinc pot section-air knife section-alloying heating section-alloying soaking section-stationary post-plating cooling section and final water cooling section, as shown in fig. 3. And a reheating section is arranged between the quick cooling section and the balanced heat preservation section, and an acid washing section and a reheating section are simultaneously arranged between the quick cooling section and the balanced heat preservation section by using other units. The movable channel section is also arranged above the air knife section, so that the switching of two or three products is realized, wherein the movable channel section (only cold-rolled product is produced), the quick cooling section (only GI product is produced) after movable plating and the alloying heating section (only GA product is produced) are arranged in parallel, and strip steel is usually cut off for product switching. And the production line for producing the GI products and the GA products adopts parallel arrangement of a quick cooling section (only the GI products are put into use) and an alloying heating section (only the GA products are put into use) after mobile plating, so that the switching of the two products is realized.
For the common preheating section and the heating section, one common method is to heat by using a radiant tube, then heat the protective gas by using combustion waste gas discharged by the radiant tube through an external heat exchanger, and finally spray the protective gas on the surface of the strip steel to preheat the strip steel to about 200 ℃. The preheating method has the following advantages compared with the method of directly spraying the waste gas generated by the combustion of the radiant tube on the surface of the strip steel to preheat the strip steel:
(1) And the pollution of the combustion waste gas to the surface of the strip steel is eliminated. Certain amount of impurities such as tar, dust, organic sulfur and the like exist in the mixed gas and the coke oven gas, so that if the combustion waste gas is directly sprayed on the surface of the strip steel to preheat the strip steel, the surface of the strip steel is polluted, and particularly, the situation is avoided when the high-surface-quality plate strip is produced.
(2) The combustion waste gas contains a certain amount of oxygen (3% -5%), and the combustion waste gas is directly sprayed on the surface of the strip steel to easily cause oxidation on the surface of the strip steel, and the surface quality of the strip steel product can be influenced. The protective gas is heated by the heat exchanger outside the furnace and then sprayed to the surface of the strip steel, and the protective gas contains 3 to 7 percent of hydrogen, so that the oxidation phenomenon can not occur, and the fuel can be saved by about 10 percent by adopting the preheating mode.
However, this technique still has the following drawbacks:
(1) The exhaust temperature of the combustion exhaust gas after preheating the strip steel is still higher, the temperature is usually higher than 350 ℃ when the high-temperature annealing material is produced, a boiler or a superheated water heating device is required to be added for secondary utilization of the waste heat of the combustion exhaust gas, the economic efficiency is obviously reduced, and the occupied area of equipment is large.
(2) The ratio of directly utilizing energy to the strip steel is low, namely a great amount of heat is still taken away by waste gas after the strip steel is preheated (the higher the temperature of the waste gas after the strip steel is preheated, the more heat is taken away), and the burnt heat is not fully transmitted to the strip steel (namely, the primary utilization rate of the energy is low).
(3) The temperature of the preheated strip steel is limited, and the preheated strip steel is difficult to exceed 250 ℃.
(4) The strip steel has low heating speed, and for high-strength steel, especially ultrahigh-strength steel, the incoming material plate shape is generally worse than that of common products, the heating speed is low, and the strip steel runs in the furnace for a long time and is easy to deviate in the furnace.
(5) Because the thermal inertia of the radiant tube heating furnace is large, when the thickness specification and the annealing target temperature change greatly, the temperature adjustment speed of the strip steel is low, the temperature control precision is poor, and the radiant tube heating furnace is very unfavorable for producing ultra-high-strength steel and has large mass loss.
Disclosure of Invention
The invention aims to provide a flexible post-treatment line suitable for producing various ultra-high strength strip steel, which can realize the following steps: 1) The temperature of the strip steel can be quickly preheated to at least 250 ℃ by fully utilizing the waste heat of the combustion waste gas of the radiant tube; 2) The cooling of the radiant tube after the waste gas is combusted fully preheats the strip steel is obviously and directly discharged, a boiler or a superheated water heating device is not required to be added for secondary utilization, so that the investment is obviously reduced, and the occupied area is reduced; 3) The waste heat of the combustion waste gas of the radiant tube is basically transmitted to the strip steel, and the primary utilization rate of heat energy is high; 4) The strip steel can be quickly and uniformly heated to above 870 ℃ by utilizing quick and efficient preheating, radiant tube heating, transverse magnetic induction heating or jet-air radiation composite heating; 5) The rapid adjustment of the annealing heating temperature of the strip steel can be realized; 6) The flexible high-strength steel special production line can flexibly produce various cold-rolled annealed, acid-washed, flash-plated, hot-dip pure zinc (GI) and alloyed hot-dip Galvanized (GA) products, so that the production line can better meet market demands; 7) The platability of the ultra-high strength steel product can be greatly improved, so that the surface quality of the ultra-high strength hot dip product can also be obviously improved; 8) 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, thereby not only reducing the production cost, but also improving the mechanical properties of various super high-strength steel products.
In order to achieve the above purpose, the technical scheme of the invention is as follows:
a flexible post-treatment line suitable for producing various ultra-high strength strip steels sequentially comprises the following stations: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, intermediate looping, flattening, outlet looping, finishing and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet radiant tube preheating section, a radiant tube heating section, a transverse magnetic induction heating section or a jet radiant composite heating section, a radiant tube soaking section, a slow cooling section, a rapid cooling section, a reheating section, a furnace nose section, a zinc pot section, an air knife section, an alloying heating section, an alloying soaking section and a post-plating cooling section which are arranged in parallel, a moving channel section, an overaging section, a final jet cooling section, a final water cooling section and an acid washing section and a flash plating section which can be optionally arranged;
the transverse magnetic induction heating section or the jet-air radiation composite heating section is arranged in parallel or in series; the series arrangement is preferred, and transverse magnetic induction heating can be selectively used according to peak-valley electricity prices, so that the production cost is reduced;
an optional withdrawal straightening station and/or a surface post-treatment station such as passivation or fingerprint resistance and the like are arranged between the flattening station and the outlet looper station;
The radiant tube heating section burns natural gas or liquefied petroleum gas or gas and other gas fuels;
the radiant tube heating section or the jet-jet radiation composite heating section burns natural gas, liquefied petroleum gas, coal gas or other gas fuel.
The jet radiant tube preheating section utilizes the nitrogen and hydrogen protective gas which is circularly utilized by heat exchange and heating of combustion waste gas in the furnace by utilizing the radiant tube heating section or/and the radiant tube soaking section, and then the nitrogen and hydrogen protective gas is jetted to the upper surface and the lower surface of the strip steel to realize forced convection heat exchange;
the rapid cooling section comprises a high-hydrogen cooling section or an aerosol cooling section or/and a water quenching cooling section.
The flexible post-treatment line adopts a jet radiant tube preheating section and adopts high hydrogen cooling or aerosol cooling or/and water quenching cooling to carry out rapid cooling treatment, then reheating and then galvanization or overaging treatment.
The furnace nose section and the moving channel section are arranged in parallel, the strip steel passes backwards from the furnace nose section and is used for producing hot-dip pure zinc or alloyed hot dip galvanized products, and the strip steel passes from the moving channel section and is used for producing cold-rolled or flash-plated products.
And an acid washing section is arranged after the final water cooling section, and the strip steel can be selected to pass through the acid washing section to produce cold-rolled acid washing products, and can also bypass to cross the acid washing section to produce cold-rolled products.
And a flash plating section is arranged after the pickling of the final water cooling section, and the pickled strip steel can be subjected to flash plating treatment to produce a flash plating product.
The flexible post-treatment line has more than three selectable process paths, and can realize the production of five different types of high-strength steel including cold rolling annealing, acid washing, flash plating, hot dip pure zinc and alloying hot dip galvanizing.
Further, an equalizing heat-preserving section is arranged between the reheating section and the furnace nose section, and the equalizing heat-preserving section is connected with the furnace nose section and the moving channel section. And the balanced heat preservation section carries out heat preservation treatment on the strip steel and then carries out hot galvanizing.
Furthermore, a movable post-plating quick cooling section is arranged between the air knife section and the post-plating cooling section, and the movable post-plating quick cooling section and the alloying heating section are arranged in parallel to realize the quick cooling of the strip steel after the hot-dip pure zinc high-strength steel product is plated; preferably, a mobile plating post-fast cooling section is arranged within a range of 10 meters above the air knife section.
And a secondary reheating section is arranged after the balanced heat preservation section and is connected with the furnace nose section and the moving channel section. And the secondary reheating section carries out secondary reheating on the balanced heat-preserving strip steel, and then carries out hot galvanizing or overaging treatment.
And a pickling section is arranged between the rapid cooling section and the reheating section, and comprises a pickling unit, a hot water scrubbing unit, a hot water rinsing unit and a hot air drying unit. The method realizes the acid washing of the surface of the strip steel, can be used for removing an oxide layer on the surface of the strip steel after aerosol cooling or/and water quenching cooling, and can also improve the platability of high-strength strip steel, particularly ultra-high-strength strip steel for hot dip galvanizing products or alloyed hot dip galvanizing products.
Preferably, the flash iron plating or the flash nickel plating section is arranged before the reheating section after the pickling section, and then the reheating section is connected, so that the platability of the ultra-high-strength strip steel can be further improved.
In addition, the invention also provides a jet radiant tube preheating device, which comprises:
the radiant tube heating furnace is characterized in that a furnace top roller chamber is arranged above a furnace body, and a steering roller is arranged in the furnace top roller chamber;
the radiant tube waste gas collection chamber is connected with the radiant tube heating furnace body through a connecting pipeline;
a preheating furnace, comprising:
a connecting hole is formed in the side wall of the upper part of the preheating furnace body, and the preheating furnace body is communicated with the radiant tube waste gas collection chamber through a communicating pipe; the top end of the preheating furnace body is provided with a furnace throat which corresponds to the furnace top roller chamber of the radiant tube heating furnace and is used for the strip steel to pass through; the bottom of the preheating furnace body is provided with a strip steel inlet, an inlet sealing device and an inlet steering roller; the upper part of the preheating furnace body is provided with a preheating furnace gas collection chamber; the lower part of the furnace body is provided with a lower partition plate with a penetrating hole to form an exhaust gas collecting chamber, and the exhaust gas collecting chamber is connected with an exhaust gas fan through an exhaust gas discharge pipeline, and preferably, a control valve is arranged on the exhaust gas discharge pipeline;
The heat exchange and air injection bellows units are arranged on two sides below a preheating furnace air collection chamber in the preheating furnace body along the height direction of the furnace body, and a strip penetrating channel for the strip 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; the air box body is internally provided with a protective gas, preferably, the air box body is internally provided with a nitrogen-hydrogen protective gas;
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 device is used for the strip steel to pass through and is respectively arranged at the lower port of the strip passing channel and the strip passing holes of the upper and lower partition plates.
Preferably, the inlet sealing device and the sealing device through which the strip steel can pass are of a nitrogen sealing structure, a nitrogen sealing chamber is adopted, and a nitrogen injection pipeline is arranged on the nitrogen sealing chamber.
According to the jet radiant tube preheating device, the nitrogen and hydrogen protective gas which is circularly utilized is directly heated by adopting in-furnace heat exchange (the heat exchange is not arranged outside the furnace), 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 to realize rapid and efficient preheating of the strip steel by forced convection heat exchange; the radiant tube combustion waste gas enters the preheating furnace gas collection chamber from the radiant tube waste gas collection chamber through a communicating pipe, then passes through a heat exchanger chamber (the heat exchanger is not arranged outside the furnace) in the preheating furnace from top to bottom, and fully exchanges heat with the nitrogen-hydrogen protective gas in the shell pass through the tube pass combustion waste gas in the process to heat the nitrogen-hydrogen protective gas, so that the radiant tube combustion waste gas in the preheating furnace is not directly contacted with the strip steel all the time, and the oxidation of the surface of the strip steel is avoided; in addition, the preheating temperature of the strip steel is high by adopting the preheating device, at least up to 250 ℃ and above, and at least 50 ℃ higher than the temperature of the common preheating strip steel; if the arrangement quantity of the jet preheating units is enough, the temperature of the burning exhaust gas of the radiant tube discharged from the multistage preheating furnace can be generally lower than 200 ℃, the radiant tube can be directly discharged, and the secondary utilization of the waste heat of the burning exhaust gas can be carried out outside the furnace without additional investment at all.
The invention also provides a jet-radiation composite heating 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 heating 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 thermal efficiency of the radiant tube can be improved by about 5%, the average working temperature of the radiant tube can be reduced, and the service life of the radiant tube can be 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 heating 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 flexible post-treatment line of the invention differs from a conventional continuous heat treatment line in that:
1) The invention has at least three or more than three selectable process paths;
2) The invention can realize the production of five different types of high-strength steel, especially super-high-strength steel, including cold rolling annealing, acid washing, flash plating, hot plating pure zinc and alloying hot galvanizing;
3) According to the technical preferred scheme, the surface post-treatments such as withdrawal straightening or/and passivation or fingerprint resistance can be performed on five different types of ultra-high strength steel;
4) According to the technical preferred scheme, secondary reheating section equipment is arranged, the double lifting of the temperature of strip steel before hot galvanizing or overaging treatment is realized, the rapid cooling of a third-generation high-strength steel (QP steel) product to a lower temperature can be realized, then the product is rapidly heated to a higher temperature to carry out long-time carbon redistribution treatment, and after the treatment is finished, the product is rapidly reheated to the temperature of a hot galvanizing zinc-entering pot for galvanizing treatment;
5) The invention changes the common preheating section into the jet radiant tube preheating section, more precisely the high-temperature nitrogen-hydrogen protective gas jet radiant tube preheating section. This is one of the novelty, creativity and practicality of the present invention, which is distinguished from the common preheating stage by the remarkable characteristics:
(1) The method has the advantages that compared with the traditional heat exchange outside the furnace, the heat loss outside the furnace is less, the waste heat of combustion waste gas is more sufficient, the heating efficiency is higher, and the heating rate is faster;
(2) in the preheating section, the radiant tube combustion waste gas enters the preheating furnace gas collection chamber from the radiant tube waste gas collection chamber through a communicating pipeline, then passes through a heat exchanger chamber (the heat exchanger is not arranged outside the furnace) in the preheating furnace from top to bottom, and fully exchanges heat with the nitrogen-hydrogen protective gas passing through the shell side in the heat exchanger in the process to heat the nitrogen-hydrogen protective gas, so that the radiant tube combustion waste gas in the preheating furnace is always not in direct contact with strip steel, and the oxidation of the surface of the strip steel is avoided;
(3) the preheating temperature of the strip steel is high and at least can reach 250 ℃ or above, and is at least 50 ℃ higher than that of the common preheating strip steel;
(4) if the arrangement quantity of the jet preheating units is enough, the temperature of the combustion exhaust gas of the radiant tube from the preheating section can be generally lower than 200 ℃, the radiant tube can be directly discharged, and the secondary utilization of the waste heat of the combustion exhaust gas is carried out outside the furnace without additional investment at all;
(5) The preheating section adopts an injection radiant tube preheating section, and the injection radiant tube preheating section is one of the core technologies of the invention.
6) The invention is characterized in that the transverse magnetic induction heating section is arranged behind the jet radiant tube preheating section, and the jet radiant tube preheating section and the transverse magnetic induction heating section are used at the same time, so that the invention is novel, creative and practical.
The rapid heating section has the beneficial effects that:
(1) the rapid adjustment of the heating temperature of the strip steel can be realized, which is very critical to the production of high-strength steel, especially ultra-high-strength steel, and the loss of the strip steel can be reduced;
(2) the strip steel can be rapidly heated to a higher temperature, and the rapid heating of the strip steel to above 870 ℃ is realized in the prior engineering through the series connection of a plurality of induction heating units of longitudinal magnetic and transverse magnetic;
(3) the radiant tube is matched with the jet-radiation composite heating unit, the heated strip steel has good temperature uniformity, and the temperature uniformity along the width direction of the strip steel can be controlled within +/-5 ℃.
The invention has the beneficial effects that:
1) The waste heat generated by heating and soaking the radiant tube can be fully utilized on line, and the temperature of the strip steel can be preheated to at least 250 ℃;
2) When the rapid heating section uses longitudinal magnetic induction and transverse magnetic induction heating, the strip steel can be rapidly heated to above 870 ℃, so that high-temperature annealing can be realized;
3) In a heating section using induction heating, the strip steel can be rapidly heated to at least 650 ℃ in one pass, so that the deviation risk of the strip steel in a high-strength steel furnace, particularly an ultrahigh-strength steel furnace, is reduced, and the requirement on the incoming strip shape is low;
4) When the heating section is provided with the radiant tube for jet composite heating, the temperature uniformity of the strip steel is good, and the temperature uniformity along the width direction of the strip steel can be controlled within +/-5 ℃;
5) The rapid adjustment of the heating temperature of the strip steel can be realized;
6) The same production line can be used for producing TRIP steel, QP steel, hot dip galvanized TRIP steel, QP steel and other ultra-high-strength steel with various surface states;
7) The martensitic ultra-high strength steel with the strength up to 1500MPa can be produced by adopting water mist cooling and acid washing, the surface quality is high, and the platability of the strip steel during hot galvanizing is good;
8) The invention can realize the production of five different types of high-strength steel, especially super-high-strength steel, such as cold rolling annealing, acid washing, flash plating, hot plating pure zinc and alloying hot galvanizing.
Drawings
FIG. 1 is a schematic diagram of a station arrangement of a conventional continuous annealing production line;
FIG. 2 is a station layout of a conventional hot dip Galvanizing (GI) line;
FIG. 3 is a station layout of a conventional Galvannealed (GA) production line;
FIG. 4 is a station layout of a flexible post-processing line according to example 1 of the present invention;
FIG. 5 is a station layout of a flexible post-processing line according to example 2 of the present invention;
FIG. 6 is a station layout of a flexible post-processing line according to example 3 of the present invention;
FIG. 7 is a station layout of a flexible post-processing line according to example 4 of the present invention;
FIG. 8 is a station layout of a flexible post-processing line according to example 5 of the present invention;
FIG. 9 is a station layout of a flexible post-processing line according to example 6 of the present invention;
FIG. 10 is a schematic diagram of a preheating device for spray radiant tubes according to an embodiment of the present invention;
FIG. 11 is a schematic view of a preheating furnace in an embodiment of the preheating device for jet radiant tubes according to the present invention;
FIG. 12 is a schematic view of an embodiment of a jet-beam radiation composite heating apparatus according to the present invention 1;
FIG. 13 is a schematic view of an embodiment of a jet-beam radiation composite heating apparatus according to the present invention 2;
fig. 14 is a schematic structural diagram of a composite heating body in an embodiment of the jet radiation composite heating device according to the present invention;
FIG. 15 is a partial perspective view of a high temperature jet bellows in an embodiment of a jet radiation complex heating device according to the present invention;
fig. 16 is a perspective view of a radiant tube in an embodiment of the jet radiant composite heating 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 simplified and combined, only one embodiment is given in this example, and other embodiments are given in the present invention, even though all the group patent examples are given only in some embodiments, various combinations generated by selecting and not selecting the optional stations 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 including alkali liquor spraying sections, alkali liquor brushing sections, electrolytic cleaning sections, hot water brushing or cold water abrasive roll brushing sections and hot water rinsing sections, even simplified and combined use of high-pressure water jet brushing sections, ultrasonic cleaning sections, high-pressure cleaning sections and other cleaning new technical equipment are considered to be derivative production lines of the invention and are also within the scope of protection of the invention. As another example, finishing stations including trimming, oiling, etc., are also within the scope of the present invention.
Referring to fig. 4, the flexible post-treatment line suitable for producing various ultra-high-strength strip steel according to the invention comprises the following stations in sequence: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, intermediate looping, flattening, outlet looping, finishing and coiling; wherein,
the central continuous post-treatment station sequentially comprises a jet radiant tube preheating section, a radiant tube heating section, a transverse magnetic induction heating section or a jet radiant composite heating section, a radiant tube soaking section, a slow cooling section, a rapid cooling section, a reheating section, a furnace nose section, a zinc pot section, an air knife section, an alloying heating section, an alloying soaking section and a post-plating cooling section which are arranged in parallel, a moving channel section, an overaging section, a final jet cooling section, a final water cooling section and an acid washing section and a flash plating section which can be optionally arranged;
the transverse magnetic induction heating section or the jet-air radiation composite heating section is arranged in parallel or in series;
an optional withdrawal straightening station and/or a surface post-treatment station such as passivation or fingerprint resistance and the like are arranged between the flattening station and the outlet looper station;
the radiant tube heating section burns natural gas or liquefied petroleum gas or gas and other gas fuels;
the jet radiant tube preheating section utilizes the nitrogen and hydrogen protective gas which is circularly utilized by heat exchange and heating of combustion waste gas in the furnace by utilizing the radiant tube heating section or/and the radiant tube soaking section, and then the nitrogen and hydrogen protective gas is jetted to the upper surface and the lower surface of the strip steel to realize forced convection heat exchange;
The rapid cooling section comprises a high-hydrogen cooling section or an aerosol cooling section or/and a water quenching cooling section.
The flexible post-treatment line has more than three selectable process paths, and can realize the production of five different types of high-strength steel including cold rolling annealing, acid washing, flash plating, hot dip pure zinc and alloying hot dip galvanizing.
Referring to fig. 5, in example 2 of the present invention, a balanced heat-insulating section is provided between the reheating section and the furnace nose section, and hot galvanizing is performed after heat-insulating treatment is performed on the strip steel.
Referring to fig. 6, in embodiment 3 of the present invention, a mobile post-plating fast cooling section is disposed between the air knife section and the post-plating cooling section, and the mobile post-plating fast cooling section and the alloying heating section are arranged in parallel, so as to realize fast cooling of the strip steel after plating of the hot-dip pure zinc high-strength steel product; preferably, a mobile plating post-fast cooling section is arranged within a range of 10 meters above the air knife section.
Referring to fig. 7, in example 4, a secondary reheating section is provided after the equilibrium maintaining section, and the equilibrium maintaining strip steel is subjected to secondary reheating and then hot galvanizing or overaging treatment.
Referring to fig. 8, in embodiment 5 of the present invention, a pickling section is disposed between a rapid cooling section (high hydrogen cooling or gas mist cooling or/and water quenching cooling section) and a reheating section, where the pickling section includes a pickling unit, a hot water scrubbing unit, a hot water rinsing unit, and a hot air drying unit, so as to implement surface pickling of the strip steel, and the pickling section can be used for removing an oxide layer on the surface of the strip steel after gas mist cooling or/and water quenching cooling, and can also improve the platability of the high-strength strip steel, especially the ultra-high-strength strip steel, for hot-dip pure zinc or alloyed hot dip galvanized products.
Referring to fig. 9, which shows embodiment 6 of the present invention, in embodiment 6, the platability of the ultra-high strength steel strip can be further improved by disposing the flash iron or the flash nickel section before the reheating section after the pickling section and then performing the reheating treatment.
Referring to fig. 10 and 11, the preheating device for the injection radiant tube according to the present invention comprises:
a radiant tube heating furnace 1, a furnace top roller chamber 101 is arranged above a furnace body, and a steering roller 102 is arranged in the furnace top roller chamber 101;
the radiant tube waste gas collection chamber 2 is connected with the furnace body of the direct fire furnace 1 through a connecting pipeline 21;
a preheating furnace 3 comprising:
a preheating furnace body 31, the upper side wall of which is provided with a connecting hole and is communicated with the radiant tube waste gas collection chamber 2 through a communicating pipe 32; a furnace throat 311 which corresponds to the furnace top roller chamber 101 of the radiant tube heating furnace 1 and is used for the strip steel to pass through is arranged at the top end of the preheating furnace body 31; the bottom of the preheating furnace body 31 is provided with a strip steel inlet, an inlet sealing device 33 and an inlet steering roller; the upper part in the preheating furnace body 31 is provided with a preheating furnace gas collection chamber 312; a lower partition 313 with a through hole is arranged at the lower part in the preheating furnace body 31 to form an exhaust gas collecting chamber 314, and is connected with an exhaust gas fan 35 through an exhaust gas discharge pipeline 34 to be discharged from a chimney 500;
a plurality of heat exchange and air injection bellows units 36 arranged on two sides below a preheating furnace gas collection chamber 312 in the preheating furnace body 31 along the height direction of the preheating furnace body 31, and a strip penetrating channel 315 for passing strip steel is formed in the middle; each heat exchange and air injection bellows unit 36 includes,
A bellows body 361 in which a plurality of heat exchanging tubes 362 are vertically arranged, and a plurality of nozzles 363 are arranged on one side surface of the bellows body 362 opposite to the threading passage 315; a waste gas secondary mixing chamber communicated with the heat exchange tube 362 is arranged between the upper and lower bellows bodies 361; the bellows 361 is filled with nitrogen-hydrogen protective gas;
a circulating fan 364, the inlet of which is arranged in the threading passage 315 and the outlet of which is arranged in the bellows 361;
the sealing device 37 through which the strip steel can pass is arranged at the lower port of the strip passing channel 315 and the strip passing hole of the lower partition 313.
Preferably, the inlet sealing device 33 and the sealing device 37 are of a nitrogen sealing structure, a nitrogen sealing chamber is adopted, and a nitrogen injection pipeline is arranged on the nitrogen sealing chamber.
Preferably, a control valve 38 is provided in the exhaust gas outlet conduit 34.
The strip steel 100 is turned by an inlet turning roller and then runs upwards, enters a preheating furnace 3 for preheating treatment after being sealed by an inlet sealing device, then enters a furnace top roller chamber, and enters a radiant tube heating furnace 1 after being turned by the turning roller; the radiant tube heating combustion waste gas enters a radiant tube waste gas collecting chamber and is communicated with a preheating furnace collecting chamber of the preheating furnace 1 through a communication pipeline, and the preheating furnace collecting chamber belongs to a closed collecting chamber, so that waste gas in the preheating furnace collecting chamber is ensured not to contact with the strip steel 100; the radiant tube combustion exhaust accumulates in the preheating furnace plenum, which is used to preheat its combustion air first.
Under the action of the pumping force of an exhaust gas fan, the combustion exhaust gas of the high-temperature radiant tubes in the preheating furnace gas collection chamber continuously passes through the jet air box units which are serially connected one by one, and heat exchange tubes (the tube side is the high-temperature combustion exhaust gas and the shell side is the nitrogen-hydrogen mixed gas) serving as heat exchangers are arranged in the jet air box units; after the nitrogen-hydrogen protective gas is heated by the radiant tube combustion waste gas through the heat exchanger, the nitrogen-hydrogen protective gas is blown to the upper surface and the lower surface of the strip steel under the action of the circulating fan to preheat the strip steel.
The radiant tube combustion waste gas flows through the heat exchange tube from top to bottom, and in the flowing process, the nitrogen-hydrogen protective gas sprayed circularly is heated by heat exchange, then enters a waste gas secondary mixing chamber between the jet air box units, is subjected to secondary mixing, performs homogenization treatment on the waste gas temperature, then enters the downstream furnace heat exchange and jet air box units until reaching the bottom nitrogen sealing device, and finally enters the waste gas collecting chamber.
The nitrogen-hydrogen protective gas passes through the heat exchange tube bundles and is heated and then is continuously sprayed to the upper surface and the lower surface of the strip steel from the nozzles under the action of the circulating fan to preheat the strip steel. The air suction port of the circulating fan is connected to the DS side and the WS side of the air injection bellows unit through a furnace pipeline, under the action of the circulating fan, the nitrogen-hydrogen mixed gas is sprayed to the surface of the strip steel and then is pumped out from two sides, and then is sprayed to the upper surface and the lower surface of the strip steel through the heat exchanger through the circulating fan, so that the nitrogen-hydrogen mixed gas is circularly sprayed to heat the strip steel.
Referring to fig. 13 to 16, the jet-radiation composite heating 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 steel was prepared, the arrangement of the processing lines of which is shown in fig. 4, and the main chemical composition (mass%) of the substrate is: uncoiling, welding, passing through an inlet loop, cleaning, preheating to 360 ℃ through a jet radiant tube, heating to 720 ℃ through the radiant tube, heating to 820 ℃ through jet radiant combination, soaking the radiant tube for 60 seconds at 820 ℃, cooling high hydrogen to 480 ℃, passing through a longitudinal magnetic induction heater (a reheating device is not required to be started in the embodiment), immersing a zinc pot through a furnace nose for hot galvanizing, controlling the weight of a coating through an air knife, cooling to about 140 ℃ through a cooling device after plating, finally cooling to below 45 ℃ through final water cooling, entering an intermediate loop, flattening, passing through an outlet loop, and coiling to finish production. The yield strength of the final product strip steel is 535MPa, the tensile strength is 817MPa, and the elongation at break is 19%.
Example 2
A high-strength steel was prepared, the arrangement of the processing lines of which is shown in fig. 5, and the main chemical components (mass%) of the substrate were: uncoiling, welding, passing through an inlet loop, cleaning, preheating a jet radiant tube to 365 ℃, heating the radiant tube to 800 ℃, heating the radiant tube to 820 ℃ by transverse magnetic induction, soaking the radiant tube at 820 ℃ for 60 seconds, slowly cooling to 750 ℃, cooling the gas mist to about 50 ℃, heating to 240 ℃, entering an overaging section through an equilibrium heat preservation section and a moving channel, carrying out overaging treatment at 240 ℃, finally cooling to about 140 ℃ by air injection, carrying out acid cleaning, then carrying out nickel flash plating, entering an intermediate loop, flattening, coiling after passing through an outlet loop, and completing production. The yield strength of the final product strip steel is 566MPa, the tensile strength is 982MPa, and the breaking elongation is 11%.
Example 3
A high-strength steel was prepared, the arrangement of the processing lines of which is shown in fig. 6, and the main chemical composition (mass%) of the substrate is: uncoiling, welding, passing through an inlet loop, cleaning, preheating to 265 ℃ by a jet radiant tube, heating to 755 ℃ by the radiant tube, heating to 875 ℃ by transverse magnetic induction, soaking the radiant tube for 50 seconds at 875 ℃, slowly cooling to 675 ℃, cooling to 380 ℃ by high hydrogen, heating to 455 ℃ again, uniformly preserving heat at about 455 ℃, immersing a zinc pot through a furnace nose for hot galvanizing, controlling the weight of a coating through an air knife, selecting moving, cooling quickly after plating, cooling to 200 ℃ or lower continuously after plating, cooling to room temperature finally, entering an intermediate loop by water cooling, flattening, coiling after passing through the outlet loop, and completing production. The yield strength of the final product strip steel is 532MPa, the tensile strength is 893MPa, and the breaking elongation is 17%.
Example 4
A high-strength steel was prepared, the arrangement of the processing lines of which is shown in fig. 7, and the main chemical composition (mass%) of the substrate is: uncoiling, welding, passing an inlet loop through a strip steel with 0.15-1.72% of Si-2.28% of Mn, preheating to 255 ℃ by adopting a jet radiant tube, heating the radiant tube to 700 ℃, heating to 780 ℃ by transverse magnetic induction, adopting jet radiant composite heating to 845 ℃, soaking the radiant tube at 845 ℃ for 60 seconds, slowly cooling to 675 ℃, cooling to 260 ℃ by high hydrogen, reheating to 410 ℃, uniformly preserving heat at 410 ℃, then reheating to 455 ℃, immersing the strip steel into a zinc pot through a furnace nose for hot galvanizing, controlling the weight of a coating by an air knife, heating to 510 ℃ by entering an alloying heating furnace, then carrying out alloying soaking for 20 seconds at 505 ℃, cooling after plating, finally cooling to room temperature, entering an intermediate loop, flattening, passing the outlet loop, and coiling to finish production. The yield strength of the final product strip steel is 728MPa, the tensile strength is 1046MPa, and the breaking elongation is 18%.
Example 5
An ultra-high strength steel was prepared, the arrangement of the processing lines of which is shown in fig. 8, and the main chemical components (mass%) of the substrate were: uncoiling, welding, passing through an inlet loop, cleaning, preheating to 255 ℃ by adopting a jet radiant tube, heating to 790 ℃ by adopting a radiant tube, heating to 890 ℃ by transverse magnetic induction, soaking the radiant tube for 60 seconds at 890 ℃, slowly cooling to 670 ℃, cooling the gas mist to about 260 ℃, pickling, reheating to 410 ℃, uniformly preserving heat at 410 ℃, reheating to 460 ℃, immersing in a zinc pot for hot galvanizing, heating to 515 ℃ by adopting an air knife to control the weight of a coating, alloying and soaking for 18 seconds at 510 ℃, cooling after plating, finally cooling to room temperature, entering an intermediate loop, flattening, coiling after passing through the outlet loop, and completing production. The final product band steel has the yield strength of 692MPa, the tensile strength of 1022MPa and the breaking elongation of 20 percent.
Example 6
An ultra-high strength steel was prepared, the arrangement of the processing lines of which is shown in fig. 9, and the main chemical composition (mass%) of the substrate is: uncoiling, welding, passing through an inlet loop, cleaning, preheating to 275 ℃ by adopting a jet radiant tube, heating to 710 ℃ by adopting the radiant tube, heating to 810 ℃ by transverse magnetic induction, soaking the radiant tube for 50 seconds at 810 ℃, slowly cooling to 670 ℃, cooling to about 50 ℃ by water quenching, pickling firstly, then plating nickel by flash, heating to 380 ℃, uniformly preserving heat at 380 ℃, reheating to 455 ℃, immersing in a zinc pot through a furnace nose, hot galvanizing, cooling after plating by controlling the weight of a coating by an air knife, finally cooling to room temperature by water, entering an intermediate loop, flattening, passing through an outlet loop, and coiling to finish production. The yield strength of the final product strip steel is 936MPa, the tensile strength is 1219MPa, and the breaking elongation is 8%.
Claims (8)
1. A flexible post-treatment line suitable for producing various ultra-high-strength strip steels, which is characterized by comprising the following stations in sequence: uncoiling, welding, inlet looping, cleaning, central continuous post-treatment, intermediate looping, flattening, outlet looping, finishing and coiling; wherein,
The central continuous post-treatment station sequentially comprises a jet radiant tube preheating section, a radiant tube heating section, a transverse magnetic induction heating section or a jet radiant composite heating section, a radiant tube soaking section, a slow cooling section, a rapid cooling section, a reheating section, a (furnace nose section, zinc pot section, air knife section, alloying heating section, alloying soaking section and post-plating cooling section) and (moving channel section, overaging section, final jet cooling section), a final water cooling section, and an optionally arranged pickling section and flash plating section;
the transverse magnetic induction heating section and the jet-air radiation composite heating section are arranged in parallel or in series;
an optional withdrawal straightening station and/or a surface post-treatment station such as passivation or fingerprint resistance and the like are arranged between the flattening station and the outlet looper station;
the radiant tube heating section burns natural gas or liquefied petroleum gas or gas and other gas fuels;
the jet radiant tube preheating section utilizes the nitrogen and hydrogen protective gas which is circularly utilized by heat exchange and heating of combustion waste gas in the furnace by utilizing the radiant tube heating section or/and the radiant tube soaking section, and then the nitrogen and hydrogen protective gas is jetted to the upper surface and the lower surface of the strip steel to realize forced convection heat exchange;
the rapid cooling section comprises a high-hydrogen cooling section or an aerosol cooling section or/and a water quenching cooling section.
2. The flexible post-treatment line suitable for producing a plurality of ultra-high strength steel strips according to claim 1, wherein an equalizing heat-preserving section is arranged between the reheating section and the furnace nose section, and the equalizing heat-preserving section is connected with the furnace nose section and the moving channel section.
3. The flexible post-treatment line suitable for producing various ultra-high-strength steel strips according to claim 1 or 2, wherein a mobile post-plating quick cooling section is arranged between the air knife section and the post-plating cooling section, and the mobile post-plating quick cooling section and the alloying heating section are arranged in parallel; preferably, a mobile plating post-fast cooling section is arranged within a range of 10 meters above the air knife section.
4. A flexible post-treatment line suitable for the production of various ultra-high-strength steel strips according to claim 2 or 3, wherein a secondary reheating section is arranged after the equalizing heat-preserving section, and the secondary reheating section is connected with the furnace nose section and the moving channel section.
5. The flexible post-treatment line suitable for producing a plurality of ultra-high-strength steel strips according to any one of claims 1 to 4, wherein a pickling section is provided between the rapid cooling section and the reheating section, the pickling section comprising a pickling unit, a hot water scrubbing unit, a hot water rinsing unit, and a hot air drying unit.
6. The flexible post-treatment line suitable for producing a plurality of ultra-high strength steel strips according to claim 5, wherein a flash iron or nickel plating section is provided before a reheating section after the pickling section, and then the reheating section is connected.
7. A jet radiant tube preheating device for a flexible post-treatment line adapted to produce a plurality of ultra-high strength steel strips as claimed in any one of claims 1 to 6, comprising:
the radiant tube heating furnace is characterized in that a furnace top roller chamber is arranged above a furnace body, and a steering roller is arranged in the furnace top roller chamber;
the radiant tube waste gas collection chamber is connected with the radiant tube heating furnace body through a connecting pipeline;
a preheating furnace, comprising:
a connecting hole is formed in the side wall of the upper part of the preheating furnace body, and the preheating furnace body is communicated with the radiant tube waste gas collection chamber through a communicating pipe; the top end of the preheating furnace body is provided with a furnace throat which corresponds to the furnace top roller chamber of the radiant tube heating furnace and is used for the strip steel to pass through; the bottom of the preheating furnace body is provided with a strip steel inlet, an inlet sealing device and an inlet steering roller; the upper part of the preheating furnace body is provided with a preheating furnace gas collection chamber; a lower partition plate with a penetrating hole is arranged at the lower part in the preheating furnace body to form an exhaust gas collecting chamber and is connected with an exhaust gas fan through an exhaust 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 a preheating furnace air collection chamber in the preheating furnace body along the height direction of the furnace body, and a strip penetrating channel for the strip 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; the bellows body is filled with a protective gas, preferably a nitrogen-hydrogen protective gas;
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 device is used for allowing the strip steel to pass through and is respectively arranged at the lower port of the strip threading channel and the strip threading hole of the lower partition plate; preferably, the inlet sealing device and the sealing device through which the strip steel can pass are of a nitrogen sealing structure, a nitrogen sealing chamber is adopted, and a nitrogen injection pipeline is arranged on the nitrogen sealing chamber.
8. A jet-radiation composite heating device for a flexible post-treatment line suitable for producing a plurality of ultra-high-strength steel strips according to any one of claims 1 to 6, 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 (1)
| Application Number | Priority Date | Filing Date | Title |
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| CN202211122521.5A CN117737398A (en) | 2022-09-15 | 2022-09-15 | Flexible post-treatment line suitable for producing various ultra-high-strength strip steels |
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| CN202211122521.5A CN117737398A (en) | 2022-09-15 | 2022-09-15 | Flexible post-treatment line suitable for producing various ultra-high-strength strip steels |
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