CN117737633A - Cold-rolled strip steel flexible aftertreatment production line suitable for producing various high-strength steels - Google Patents
Cold-rolled strip steel flexible aftertreatment production line suitable for producing various high-strength steels Download PDFInfo
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- CN117737633A CN117737633A CN202211122519.8A CN202211122519A CN117737633A CN 117737633 A CN117737633 A CN 117737633A CN 202211122519 A CN202211122519 A CN 202211122519A CN 117737633 A CN117737633 A CN 117737633A
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- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Abstract
A cold-rolled strip steel flexible post-treatment production line suitable for producing various high-strength 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 jet radiant composite 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) and (a moving channel section, an overaging section and a final jet cooling section), a final water cooling section, an optional pickling section and an optional flash plating section. The invention can produce five varieties of ultra-high strength strip steel products of cold rolling annealing, acid washing, flash plating, hot plating pure zinc and alloying hot galvanizing on the same production line.
Description
Technical Field
The invention relates to the technical field of continuous annealing heat treatment of strip steel, in particular to a cold-rolled strip steel flexible post-treatment production line suitable for producing various high-strength steel.
Background
With the increase of the market demand of ultra-high-strength steel, a plurality of cold-rolled strip steel continuous heat treatment production lines capable of producing ultra-high-strength steel are established by the steel enterprises of China through joint materials or technology introduction in recent years, and the production lines comprise a strip steel continuous annealing production line, a hot dip pure zinc (GI) production line, an alloying hot dip Galvanizing (GA) production line and a continuous annealing/hot dip galvanizing dual-purpose production line. These production lines mainly adopt the traditional technology to produce the ultra-high strength steel.
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, and 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 proportion 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, and the strip steel with low heating speed has long running time in the furnace 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, the production of ultra-high strength steel is very unfavorable, and the product quality loss is large.
(6) Due to the fact that the thermal inertia of the radiant tube soaking furnace is large, when the thickness specification and the annealing target temperature change greatly, the soaking temperature of the strip steel is slowly adjusted, transition materials are required to be added, or the actual soaking temperature fluctuation of the strip steel is large.
Disclosure of Invention
The invention aims to provide a cold-rolled strip steel flexible post-treatment production line suitable for producing various high-strength steels, 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 of equipment 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 heated to more than 650 ℃ by utilizing quick and efficient preheating and quick heating (longitudinal magnetic induction heating), and if the transverse magnetic induction heating and jet radiation composite heating are used in a matched mode in the follow-up process, the strip steel can be quickly and uniformly heated to more than 850 ℃; 5) The rapid adjustment of the heating temperature and the soaking 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, not only can reduce the production cost, but also can improve the mechanical properties of various super high-strength steel products, and remarkably 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 cold-rolled strip steel flexible post-treatment production line suitable for producing various high-strength 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 jet radiant composite 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, an optional pickling section and a flash plating section;
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 waste gas generated by combustion of the radiant tube heating section to exchange heat in the furnace to heat the recycled nitrogen-hydrogen protective gas, and then the nitrogen-hydrogen protective gas is jetted to the upper surface and the lower surface of the strip steel to realize forced convection heat exchange;
the transverse magnetic induction heating sections or the jet-air radiation composite heating sections are arranged in parallel or in series, preferably in series, so that the transverse magnetic induction heating can be selected according to peak-valley electricity price, and the production cost is reduced;
The jet-radiation composite soaking section adopts a mode of combining forced convection and radiation to quickly soak the strip steel, so that the uniformity of the strip steel temperature is improved, and the quick adjustment of the strip steel soaking temperature is realized;
the rapid cooling section comprises a high-hydrogen cooling section or/and an aerosol cooling section or/and a water quenching cooling section;
an optional withdrawal and 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, and the strip steel can be withdrawn and straightened and/or subjected to surface post-treatment.
The production line adopts high hydrogen cooling or aerosol cooling or/and water quenching cooling to perform rapid cooling treatment while adopting a jet radiant tube preheating section, then reheating and then galvanization or overaging treatment;
the furnace nose section and the moving channel section are arranged in parallel, strip steel passes through the furnace nose section backwards and is used for producing hot-dip pure zinc or alloyed hot dip galvanized products, and strip steel passes through the moving channel section and is used for producing cold-rolled or flash-plated products;
the pickling section is arranged after the final water cooling section, and the strip steel can be selected to pass through the pickling section to produce cold-rolled pickling products, and can also bypass to cross the pickling section to produce cold-rolled products;
a flash plating section is arranged behind the pickling section after the final water cooling section, and the strip steel after pickling can also be subjected to flash plating treatment to produce a flash plating product;
The production 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 is respectively connected with the furnace nose section and the moving channel section; the hot galvanizing can be performed after the heat preservation treatment is performed on the strip steel.
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 quick cooling of the strip steel after the hot-dip pure zinc high-strength steel product is plated; further preferably, a fast cooling section after mobile plating is arranged within a range of 10 meters above the air knife section.
A secondary reheating section is arranged after the balanced heat preservation section and is respectively connected with the furnace nose section and the moving channel section; and (3) carrying out secondary reheating on the balanced heat-preserving strip steel, and then carrying out hot galvanizing or overaging treatment.
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, a flash iron or nickel plating section is arranged before the reheating section after the pickling section, and the flash iron or nickel plating section is connected with the reheating section, so that the platability of the ultra-high-strength strip steel can be further improved.
Preferably, a longitudinal magnetic induction heating section is arranged in front of the radiant tube heating section and is used for further and rapid lifting of the heating temperature of the strip steel.
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/soaking device, which comprises:
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; 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/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 heating/soaking device has the functions of combustion radiation (namely, a 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 vertical continuous annealing furnace body is reduced.
The production line of the invention is different from the traditional process in that:
1) The invention has 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) The invention can carry out surface post-treatment such as withdrawal straightening or/and passivation or fingerprint resistance on five different types of ultra-high strength steel including cold rolling annealing, acid washing, flash plating, hot plating pure zinc and alloying hot galvanizing;
4) The invention is provided with the secondary reheating section, thereby realizing the twice lifting of the temperature of the strip steel before hot galvanizing or overaging treatment, and realizing the rapid cooling of third-generation high-strength steel (QP steel) products to lower temperature, then rapidly heating to higher temperature on the horse for long-time carbon redistribution treatment, and rapidly reheating to the temperature of a hot galvanizing zinc-entering pot for galvanizing treatment after the treatment is finished;
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, which is one of the novelty, creativity and practicability of the invention, and the remarkable characteristics of the invention are that:
(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 the combustion waste gas is utilized more fully, the heating efficiency is higher, and the heating rate is faster;
(2) in the preheating section, 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 section from top to bottom, and fully exchanges heat with nitrogen-hydrogen protective gas in the shell pass through the heat exchanger in the process, and the nitrogen-hydrogen protective gas is heated by the combustion waste gas, so that the radiant tube combustion waste gas is not directly contacted with strip steel all the time in the preheating section, 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 is designed to be an injection radiant tube preheating section.
6) The invention is provided with a transverse magnetic induction heating section after the jet radiant tube preheating section, and the preferable technical scheme is that a longitudinal magnetic induction heating section is also arranged before the radiant tube heating section for further and rapid lifting of the strip steel heating temperature, and the jet radiant composite heating section of the matched radiant tube is preferable for improving the heating temperature uniformity and is used for homogenizing the strip steel temperature and adjusting the strip steel shape. The simultaneous use of the jet radiant tube preheating section and the rapid heating section is yet another embodiment of the novelty, creativity and practicality of the present invention.
7) And a soaking section before the slow cooling section adopts a radiant tube jet-radiation composite rapid soaking section. The strip steel is soaked in a mode of combining forced convection and radiation, so that the uniformity of the soaking temperature of the strip steel can be improved, the soaking temperature of the strip steel can be quickly adjusted, and the fluctuation of the actual temperature of the strip steel at the soaking section is reduced.
The beneficial effects of the invention using the rapid heating section are as follows: (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 quality loss of the strip steel caused by inconsistent temperature can be reduced; (2) the strip steel can be heated to a higher temperature, and the rapid heating of the strip steel to 880 ℃ is realized in the prior art through series connection of a plurality of induction heaters of longitudinal magnetic and transverse magnetic; (3) the radiant tube is matched for jet-radiation of the composite heating section, 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 more than 850 ℃, so that high-temperature annealing can be realized;
3) The rapid heating section can rapidly heat the strip steel to at least 650 ℃ in one pass, so that the deviation risk of the strip steel in the high-strength steel furnace, particularly the ultra-high-strength steel furnace, is reduced, and the requirement on the incoming strip shape can be properly reduced;
4) The rapid adjustment of the strip steel temperature of the heating section and the strip steel temperature of the soaking section can be realized by the application of the jet-air radiation composite heating technology;
5) The same production line can be used for producing continuous annealing cold rolled DP steel, MS steel, TRIP steel, QP steel, hot dip galvanized DP steel, TRIP steel, QP steel and other ultra-high-strength steel;
6) The martensitic ultra-high strength steel with the strength up to 1500MPa can be produced by adopting water mist cooling, acid washing or acid washing and flash plating, the surface quality is high, and the platability of the strip steel during hot galvanizing is good;
7) 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 layout of the production line of embodiment 1 of the present invention;
FIG. 5 is a layout of the production line in accordance with embodiment 2 of the present invention;
FIG. 6 is a station layout of the production line of example 3 of the present invention;
FIG. 7 is a station layout of the production line of example 4 of the present invention;
FIG. 8 is a layout of the production line of embodiment 5 of the present invention;
FIG. 9 is a layout of the production line of embodiment 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-propelled radiant composite heating/soaking device according to the present invention 1;
FIG. 13 is a schematic view of an embodiment of a jet-propelled radiant composite heating/soaking device according to the present invention in FIG. 2;
fig. 14 is a schematic structural diagram of a composite heating body in an embodiment of the air jet radiation composite heating/soaking 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 radiant composite heating/soaking apparatus according to the present invention;
Fig. 16 is a perspective view of a radiant tube in an embodiment of the jet radiant composite heating/soaking device according to the present invention.
Detailed Description
The following further describes the implementation method of the present invention with reference to examples and drawings: 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 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. 4, in embodiment 1 of the present invention, the flexible post-treatment production line for cold-rolled steel strips suitable for producing various high-strength 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 jet radiant composite soaking section, a slow cooling section, a rapid cooling section (high hydrogen cooling or aerosol cooling or/and water quenching cooling section), a reheating section, a parallel-arranged (furnace nose section+zinc pot section+air knife section+alloying heating section+alloying soaking section+post-plating cooling section), a moving channel section+overaging section+final jet cooling section) and a final water cooling section;
an optional withdrawal straightening station and/or a surface post-treatment station such as passivation or fingerprint resistance are arranged between the flattening station and the outlet looper station;
the transverse magnetic induction heating section or the jet-air radiation composite heating section is arranged in parallel or in series;
the furnace nose section and the movable channel section are arranged in parallel, strip steel passes through the furnace nose section backwards and is used for producing hot-dip pure zinc or alloyed hot dip galvanized products, and strip steel passes through the movable channel section and is used for producing cold-rolled or flash-plated products;
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;
a flash plating section is arranged behind the pickling section after the final water cooling section, and the pickled strip steel can be subjected to flash plating treatment to produce a flash plating product;
the production line provided by the invention has more than three selectable process paths, and can realize the production of five different types of high-strength steel including cold rolling annealing, pickling, 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, on the basis of embodiment 2, 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.
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, an embodiment 5 of the present invention is shown, in embodiment 5, a pickling section is disposed between the rapid cooling section (high hydrogen cooling or gas mist cooling or/and water quenching cooling section) and the 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 pickling of the surface 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, in example 6 of the present invention, the platability of the ultra-high strength steel strip can be further improved by providing a flash iron or nickel plating section before the reheating section after the pickling section and then performing the reheating treatment.
Preferably, a longitudinal magnetic induction heating section is arranged before the radiant tube is heated for further rapid elevation of the strip steel heating temperature.
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/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 manufacturing line of high-strength steel strip steel is shown in figure 4, the main chemical composition (mass%) of a substrate is 0.11-0.17% of Si-1.95% of Mn, strip steel is uncoiled, welded, inlet loops pass through and are cleaned, then are preheated to 265 ℃ through a jet radiant tube, then are heated to 750 ℃, then are heated to 895 ℃ through transverse magnetic induction, and are subjected to jet radiation composite soaking for 50 seconds at 895 ℃, after being slowly cooled to 670 ℃ and being cooled to 475 ℃, the strip steel is firstly immersed into a zinc pot through a longitudinal magnetic induction heater (a reheating device, the longitudinal magnetic induction heater does not need to be started) through a furnace nose, hot dip is carried out, after the plating weight is controlled through an air knife, the strip steel is cooled to about 140 ℃, finally is cooled to below 45 ℃ through final water cooling, then enters into an intermediate loop, is flattened, is pulled and corrected, and the outlet loop is subjected to finishing and coiling, and the production is completed. The yield strength of the final product strip steel is 552MPa, the tensile strength is 859MPa, and the breaking elongation is 19%.
Example 2
A process for preparing high-strength steel strip includes such steps as uncoiling the strip steel whose main chemical component (mass%) is 0.16-0.25% Si-2.4% Mn, welding, passing through entrance loop, washing, preheating to 275 deg.C by jet radiant tube, heating to 575 deg.C, heating to 820 deg.C by jet radiant combination, soaking for 60 seconds, slow cooling to 755 deg.C, quenching in water, heating to 230 deg.C, heat preserving at 230 deg.C, passing through moving channel, overageing at 230 deg.C, cooling to 150 deg.C by air jet, water cooling to room temperature, pickling, passing through intermediate loop, levelling, drawing, passing through exit loop, finishing, and coiling. The yield strength of the final product strip steel is 1312MPa, the tensile strength is 1532MPa, and the elongation at break is 4%.
Example 3
A process for preparing high-strength steel strip includes such steps as unwinding the strip steel whose chemical composition (mass%) is 0.14-1.6-2.1% Mn, welding, passing through entrance loop, washing, preheating to 260 deg.C by jet radiant tube, heating to 560 deg.C by transverse magnetic induction, heating to 830 deg.C by jet radiant, heating to 850 deg.C by jet radiant, soaking for 60 seconds, slow cooling to 670 deg.C, cooling to 280 deg.C by high hydrogen, heating to 455 deg.C, heat insulating, immersing in zinc pot, hot plating, moving, cooling to 370 deg.C, cooling to 150 deg.C, cooling to room temperature, passing through intermediate loop, leveling, fingerprint-resisting treatment, finishing and winding. The final product band steel has the yield strength of 692MPa, the tensile strength of 1018MPa and the breaking elongation of 20 percent.
Example 4
A manufacturing line of high-strength steel strip steel is shown in figure 7, the strip steel with the main chemical composition (mass%) of 0.16% C-1.75% Si-2.25% Mn is uncoiled, welded, passed through an inlet looper, cleaned, preheated to 255 ℃ by adopting a jet radiant tube, then heated to 555 ℃, then heated to 850 ℃ by jet radiation compounding, soaked for 70 seconds by jet radiation compounding, slowly cooled to 690 ℃, cooled to 230 ℃ by high hydrogen, then heated to 420 ℃, kept at 420 ℃ in balance, then reheated to 460 ℃ and immersed in a zinc pot for hot galvanizing, passed through an alloying heating section (heating function is not put into) and an alloying soaking section (heating function is not put into), then cooled after plating, cooled to below 150 ℃, finally cooled to room temperature by water, fed into an intermediate looper, subjected to fingerprint resistance treatment after leveling, passed through an outlet looper, coiled and finished product. The final product band steel has yield strength of 762MPa, tensile strength of 1039MPa and elongation at break of 18%.
Example 5
A manufacturing line of high-strength steel strip steel is shown in figure 8, wherein the main chemical composition (mass%) of a substrate is 0.11-0.08% of C-0.08% of Si-2.0% of Mn, strip steel is uncoiled, welded, passed through an inlet loop and cleaned, preheated to 250 ℃ by adopting a jet radiant tube, heated to 550 ℃ by adopting a radiant tube, then heated to 700 ℃ by transverse magnetic induction, then heated to 810 ℃ by jet radiation in a compounding way, soaked for 60 seconds by jet radiation in a compounding way, slowly cooled to 675 ℃, cooled to room temperature by water quenching, pickled, then heated to 220 ℃ again, uniformly kept at 220 ℃, passed through a secondary reheating section (without being input by a heating function), passed through a moving channel section, passed through an overaging section, subjected to overaging treatment at about 220 ℃, finally cooled to 150 ℃ by jet air, finally cooled to room temperature, passed through an intermediate loop, flattened, subjected to chromium-free passivation treatment after withdrawal and finished by an outlet loop, coiled to complete production. The yield strength of the final product strip steel is 785MPa, the tensile strength is 1033MPa, and the elongation at break is 7%.
Example 6
A process for preparing high-strength steel strip includes such steps as uncoiling the strip steel whose main chemical component (mass%) is 0.088-0.28% Si-2.1% Mn, welding, passing through entrance loop, washing, preheating to 277 deg.C by jet radiant tube, heating to 575 deg.C by transverse magnetic induction, heating to 810 deg.C by jet radiation, immersing the radiant tube in heat for 60 seconds, slow cooling to 680 deg.C, cooling to 50 deg.C by aerosol, pickling, plating by nickel, immersing in zinc pot for hot dip, controlling the weight of plated layer by air knife, alloying for 20 seconds, cooling to 150 deg.C, cooling to room temp, cooling to intermediate loop, levelling, drawing, coiling, and finished product. The yield strength of the final product strip steel is 918MPa, the tensile strength is 1192MPa, and the breaking elongation is 8.5%.
Claims (9)
1. A cold-rolled strip steel flexible post-treatment production line suitable for producing various high-strength steels is characterized by sequentially comprising 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 jet radiant composite 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, an optional pickling section and a flash plating section;
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 waste gas generated by combustion of the radiant tube heating section to exchange heat in the furnace to heat the recycled nitrogen-hydrogen protective gas, and then the nitrogen-hydrogen protective gas is jetted to the upper surface and the lower surface of the strip steel to realize forced convection heat exchange;
the transverse magnetic induction heating section or the jet-air radiation composite heating section is arranged in parallel or in series;
the jet-radiation composite heating soaking section adopts a mode of combining forced convection and radiation to quickly soak the strip steel;
the rapid cooling section comprises a high-hydrogen cooling section or/and an aerosol cooling section or/and a water quenching cooling section;
an optional withdrawal straightening station and/or a surface post-treatment station such as passivation or fingerprint resistance is arranged between the flattening station and the outlet looper station.
2. The flexible post-treatment production line for cold-rolled steel strips suitable for producing various high-strength steels according to claim 1, wherein an equalizing heat-preserving section is arranged between the reheating section and the furnace nose section and is respectively connected with the furnace nose section and the moving channel section.
3. The flexible post-treatment production line for cold-rolled steel strips suitable for producing various high-strength steels 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; further preferably, a fast cooling section after mobile plating is arranged within a range of 10 meters above the air knife section.
4. A cold rolled steel strip flexible post-treatment line suitable for producing a plurality of high strength steels according to claim 2 or 3, wherein a secondary reheating section is provided after the balancing heat preservation section, the secondary reheating section being respectively connected to the furnace nose section and the moving channel section.
5. The flexible post-treatment production line for cold-rolled steel strips suitable for producing various high-strength steels according to any one of claims 1 to 4, wherein 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.
6. The flexible post-treatment line according to any one of claims 1 to 5, wherein a flash iron or nickel section is provided before the reheating section after the pickling section, the flash iron or nickel section being connected to the reheating section.
7. A flexible post-treatment line suitable for the production of a plurality of ultra-high strength steel strips according to any of claims 1 to 6, characterized in that a longitudinal magnetic induction heating section is provided before the radiant tube heating section.
8. A spray radiant tube preheating device for a cold rolled strip steel flexible post-treatment line suitable for producing a plurality of high strength steels according to any one of claims 1 to 7, 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.
9. A jet-radiation composite heating/soaking apparatus for a cold-rolled strip steel flexible post-treatment line suitable for producing a plurality of high-strength steels according to any one of claims 1 to 7, characterized by 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 |
|---|---|---|---|
| CN202211122519.8A CN117737633A (en) | 2022-09-15 | 2022-09-15 | Cold-rolled strip steel flexible aftertreatment production line suitable for producing various high-strength steels |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211122519.8A CN117737633A (en) | 2022-09-15 | 2022-09-15 | Cold-rolled strip steel flexible aftertreatment production line suitable for producing various high-strength steels |
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| Publication Number | Publication Date |
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| CN117737633A true CN117737633A (en) | 2024-03-22 |
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| CN202211122519.8A Pending CN117737633A (en) | 2022-09-15 | 2022-09-15 | Cold-rolled strip steel flexible aftertreatment production line suitable for producing various high-strength steels |
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| Country | Link |
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| CN (1) | CN117737633A (en) |
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