Continuous annealing device and method

Abstract

Disclosed in the present specification are a continuous annealing device and method. The continuous annealing device comprises: a heating section (1), a soaking section (2), a slow cooling section (3), a first rapid cooling section (4), a first aging section (5), a second rapid cooling section (6) and a second aging section (7) which are successively provided; the heating section (1) is used for heating strip steel; the soaking section (2) is used for performing heat preservation treatment on the heated strip steel; the slow cooling section (3) is used for performing first cooling treatment on the strip steel subjected to the heat preservation treatment at a first cooling rate; the first rapid cooling section (4) is used for performing second cooling treatment on the strip steel subjected to the first cooling treatment at a second cooling rate; the first aging section (5) is used for performing first aging treatment on the strip steel subjected to the second cooling treatment; the second rapid cooling section (6) is used for performing third cooling treatment on the strip steel subjected to the first aging treatment at a third cooling rate; and the second aging section (7) is used for performing second aging treatment on the strip steel subjected to the third cooling treatment, the second cooling rate and the third cooling rate both being greater than the first cooling rate.

Description

Continuous annealing apparatus and method Cross-reference to related applications

[0001] This application claims priority to Chinese Patent Application No. 2024112292184, filed September 3, 2024, the entire contents of which are incorporated herein by reference. TECHNICAL FIELD

[0002] The present disclosure belongs to the technical field of automotive steel and engineering structure steel, and particularly relates to a continuous annealing apparatus and method. BACKGROUND

[0003] With the development of the automobile industry and the increasingly stringent government regulations, the automobile industry has higher and higher demands for light weight, high safety, low emission, and low cost. In order to reduce fuel consumption and improve safety, the strength grade of automobile parts is getting higher and higher, and the parts are getting more and more complex. Typical steel grades of cold-rolled ultra-high strength steel include DP (Dual Phase) steel, TRIP (Transformation Induced Plasticity) steel, MS (Martensitic) steel, and third-generation high-strength steel. DP steel has been widely used in the automobile industry due to its good comprehensive mechanical properties, low alloy content, and easy mass production. However, for some complex parts, DP steel has the defect of insufficient forming ability and is prone to cracking at parts with large strain. The production process of common DP steel is shown in FIG. 1, which includes a heating section, a soaking section, a slow cooling section, a fast cooling section, an aging section, and a final cooling section.

[0004] To solve the problem of deformation of complex parts, advanced steel companies at home and abroad have developed third-generation high-strength steel with excellent overall and local forming properties. Typical steel grades include QP (Quenching and Partitioning) steel. The production process of common QP steel is shown in FIG. 2, which includes a heating section, a soaking section, a slow cooling section, a fast cooling section, an aging section, and a final cooling section. The elongation of QP steel is significantly improved compared to DP steel. For example, the A80 of DP980 is generally about 13%, while the A80 of QP980 is as high as about 19%, which is more than 40% higher than that of DP980. However, as the requirements for forming properties of some vehicle body parts become higher and higher, traditional QP980 has been difficult to meet the relevant requirements. In addition, as the strength grade of QP steel increases, its elongation gradually decreases, making it difficult to meet the stamping requirements of complex parts. Therefore, how to further improve the forming properties of third-generation high-strength steel is a problem that needs to be solved. SUMMARY

[0005] Embodiments of the present disclosure provide a continuous annealing apparatus and method, which aims to further improve the forming properties of third-generation high-strength steel.

[0006] Other features and advantages of the present disclosure will be apparent from the detailed description that follows, or can be learned by practice of the present disclosure.

[0007] According to a first aspect of the present disclosure, there is provided a continuous annealing device, comprising: a heating section, a soaking section, a slow cooling section, a first fast cooling section, a first aging section, a second fast cooling section and a second aging section arranged in sequence; wherein the heating section is configured to perform a heating treatment on a strip steel; the soaking section is configured to perform a heat preservation treatment on the strip steel after the heating treatment; the slow cooling section is configured to perform a first cooling treatment on the strip steel after the heat preservation treatment at a first cooling speed; the first fast cooling section is configured to perform a second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed; the first aging section is configured to perform a first aging treatment on the strip steel after the second cooling treatment; the second fast cooling section is configured to perform a third cooling treatment on the strip steel after the first aging treatment at a third cooling speed; and the second aging section is configured to perform a second aging treatment on the strip steel after the third cooling treatment, wherein the second cooling speed and the third cooling speed are both greater than the first cooling speed.

[0008] According to a second aspect of the present disclosure, there is provided a continuous annealing method applied to the continuous annealing device described above, comprising: controlling the heating section to perform a heating treatment on a strip steel; controlling the soaking section to perform a heat preservation treatment on the strip steel after the heating treatment; controlling the slow cooling section to perform a first cooling treatment on the strip steel after the heat preservation treatment at a first cooling speed; controlling the first fast cooling section to perform a second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed; controlling the first aging section to perform a first aging treatment on the strip steel after the second cooling treatment; controlling the second fast cooling section to perform a third cooling treatment on the strip steel after the first aging treatment at a third cooling speed; and controlling the second aging section to perform a second aging treatment on the strip steel after the third cooling treatment, wherein the second cooling speed and the third cooling speed are both greater than the first cooling speed.

[0009] According to a third aspect of the present disclosure, there is provided a continuous annealing device, comprising a processor and a memory, wherein the memory stores computer program instructions capable of being executed by the processor, and the processor, when executing the computer program instructions, implements the steps of the method according to the second aspect.

[0010] It should be understood that the general description above and the following detailed description are only exemplary and explanatory, and cannot limit the present disclosure. BRIEF DESCRIPTION OF DRAWINGS

[0011] The accompanying drawings, which are incorporated herein and constitute part of the specification, illustrate embodiments consistent with the present disclosure and, together with the description, further serve to explain the principles of the present disclosure. It is to be understood that the drawings are only schematic, and that they do not necessarily represent a limiting case of the application. In the drawings:

[0012] FIG. 1 shows a schematic diagram of a production process of DP steel in the related art;

[0013] FIG. 2 shows a schematic diagram of a production process of QP steel in the related art;

[0014] FIG. 3 shows a block diagram of a continuous annealing device according to some embodiments of the present disclosure;

[0015] FIG. 4 shows a schematic diagram of a structure of the continuous annealing device in FIG. 3;

[0016] FIG. 5 shows a schematic diagram of a production process applied to the continuous annealing device in FIG. 4;

[0017] FIG. 6 shows a flowchart of a continuous annealing method according to some embodiments of the present disclosure.

[0018] Explanation of reference numerals: DETAILED DESCRIPTION

[0019] The technical solutions in the embodiments of the present disclosure will be described clearly and completely below with reference to the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative effort belong to the scope of the present disclosure.

[0020] In addition, the described features, structures, or characteristics can be combined in any suitable manner in one or more embodiments. In the following description, numerous specific details are provided to give a sufficient understanding of embodiments of the present disclosure. However, one of ordinary skill in the art will recognize that the technical solutions of the present disclosure can be practiced without one or more of the specific details, or with other methods, components, devices, steps, etc. In other cases, well-known methods, devices, implementations, or operations are not shown or described in detail to avoid obscuring the aspects of the present disclosure.

[0021] The flowcharts shown in the drawings are only exemplary and do not necessarily include all contents and operations / steps, nor do they have to be executed in the order described. For example, some operations / steps can be further divided, and some operations / steps can be combined or partially combined, so the actual execution order can be changed according to the actual situation.

[0022] It is also important to note that the terms "first", "second" and the like in the description and in the claims of the present disclosure, as well as above-mentioned figures, are used to distinguish between similar objects and are not necessarily used to describe a particular sequential or chronological order. It is to be understood that the objects so described can be interchangeable that the embodiments of the present disclosure described herein can operate in other sequences than those described or illustrated herein.

[0023] In order to further improve the formability of the third generation of automobile steel, a new annealing production line needs to be used. A domestic invention patent with publication number CN105849289B proposes an annealing production line, which can produce ultra-high strength steel with excellent formability. This patent adds a heating station and a slow cooling or constant temperature holding station before the traditional annealing production line, which requires a very large modification to the traditional annealing production line. Since the heating station has a slow heating rate and the slow cooling or constant temperature holding station has a slow cooling rate, the annealing production line will be significantly lengthened, and the modification cost will be very high. Since the annealing production line is relatively long, and the second cooling station in the annealing production line does not have induction heating capability, the annealing production line not only has a single type of annealing process that can be used, but also makes it difficult to produce high-strength steel (such as QP steel) using existing annealing processes.

[0024] The present disclosure provides a new type of continuous annealing device, which adds a second fast cooling section and a second aging section after the aging section of the traditional annealing production line, so that the elongation of the strip steel after annealing treatment is significantly improved, and the hole expansion rate is also improved, thus the formability is significantly improved. The continuous annealing device can not only produce DP steel, QP steel and other steel grades according to existing annealing processes, but also can produce third generation high-strength steel with higher elongation by using a new type of annealing process.

[0025] FIG. 3 shows a block diagram of a continuous annealing device according to some embodiments of the present disclosure. As shown in FIG. 3, in some embodiments, the continuous annealing device can include a heating section 1, a soaking section 2, a slow cooling section 3, a first fast cooling section 4, a first aging section 5, a second fast cooling section 6, and a second aging section 7 arranged in sequence; wherein the heating section 1 is used for heating treatment of the strip steel; the soaking section 2 is used for heat preservation treatment of the strip steel after heating treatment; the slow cooling section 3 is used for first cooling treatment of the strip steel after heat preservation treatment at a first cooling speed; the first fast cooling section 4 is used for second cooling treatment of the strip steel after the first cooling treatment at a second cooling speed; the first aging section 5 is used for first aging treatment of the strip steel after the second cooling treatment; the second fast cooling section 6 is used for third cooling treatment of the strip steel after the first aging treatment at a third cooling speed; and the second aging section 7 is used for second aging treatment of the strip steel after the third cooling treatment, the second cooling speed and the third cooling speed are both greater than the first cooling speed.

[0026] Fig. 4 shows a structural schematic diagram of the continuous annealing device in Fig. 3. Referring to Figs. 3 and 4 together, the heating section 1 can adopt a heating device such as a radiant tube to perform heating treatment on the strip steel, and the heating temperature range can be 0-950°C. The soaking section 2 can also adopt a heating device such as a radiant tube to perform heat preservation treatment on the strip steel, and the soaking section 2 should have good heat preservation capacity, and the soaking temperature fluctuation range should be less than or equal to ±5°C as much as possible, and the soaking time range can be 0.5-5 min. The slow cooling section 3 can adopt a slow cooling fan 31 to perform first cooling treatment on the strip steel after heat preservation treatment, so as to slowly cool the strip steel after heat preservation treatment, and the cooling temperature range of the slow cooling section 3 can be controlled to be 0-200°C.

[0027] In some embodiments, the first fast cooling section 4 can include a first fast cooling fan 41, the first aging section 5 can include a first induction heater 51, a first radiant tube 52 and a first cooling air pipe 53, the second fast cooling section 6 can include a second fast cooling fan 61, and the second aging section 7 can include a second induction heater 71, a second radiant tube 72 and a second cooling air pipe 73; wherein the first radiant tube 52 and the first cooling air pipe 53 are arranged between the first induction heater 51 and the second fast cooling fan 61; and the second radiant tube 72 and the second cooling air pipe 73 are arranged between the second induction heater 71 and a post-aging device (not shown in the figure).

[0028] It can be understood that the first fast cooling section 4 can adopt the first fast cooling fan 41 to perform second cooling treatment on the strip steel after the first cooling treatment, so as to rapidly cool the strip steel after the first cooling treatment, and the cooling temperature range of the first fast cooling section can be 0-800°C.

[0029] The first aging section 5 can adopt the first induction heater 51, the first radiant tube 52 and the first cooling air pipe 53 to perform first aging treatment on the strip steel after the second cooling treatment, the induction heating temperature range of the first induction heater 51 can be 0-800°C to meet the production process requirements of different steel grades, and the aging time range of the first aging section 5 can be 0.1-15 min. During the first aging treatment, the strip steel is heated by the first induction heater 51, and the temperature of the heated strip steel is kept constant by the first radiant tube 52 or the first cooling air pipe 53, so that the fluctuation range of the first aging temperature is less than or equal to ±5°C as much as possible.

[0030] The second fast cooling section 6 can adopt the second fast cooling fan 61 to perform third cooling treatment on the strip steel after the first aging treatment, so as to rapidly cool the strip steel after the first aging treatment, and the cooling temperature range of the second fast cooling section 6 can be the same as the induction heating temperature range of the first induction heater 51, i.e. 0-800°C.

[0031] The second aging section 7 can adopt the second induction heater 71, the second radiation tube 72 and the second cooling air pipe 73 to perform the second aging treatment on the strip steel after the third cooling treatment, the induction heating temperature range of the second induction heater 71 can be 0-500℃, and the aging time range of the second aging section 7 can be 0.1-15min. During the second aging treatment, the strip steel is heated by the second induction heater 71, and the temperature of the heated strip steel is kept constant by the second radiation tube 72 or the second cooling air pipe 73, so that the fluctuation range of the second aging temperature is less than or equal to ±5℃ as much as possible.

[0032] In some embodiments, the continuous annealing device can further comprise a first pyrometer I, a second pyrometer II, a third pyrometer III, a fourth pyrometer IV, a fifth pyrometer V, a sixth pyrometer VI, a seventh pyrometer VII, an eighth pyrometer VIII and a ninth pyrometer IX; wherein the first pyrometer I is arranged at the outlet of the heating section 1; the second pyrometer II is arranged at the outlet of the soaking section 2; the third pyrometer III is arranged at the outlet of the slow cooling section 3; the fourth pyrometer IV is arranged at the outlet of the first fast cooling section 4; the fifth pyrometer V is arranged at the output end of the first induction heater 51; the sixth pyrometer VI is arranged at the outlet of the first aging section 5; the seventh pyrometer VII is arranged at the outlet of the second fast cooling section 6; the eighth pyrometer VIII is arranged at the output end of the second induction heater 71; and the ninth pyrometer IX is arranged at the outlet of the second aging section 7.

[0033] It should be noted that the number of first induction heaters in the first aging section is usually multiple, in which case the first induction heaters are usually arranged in series. If the first induction heater connected with the first fast cooling fan 41 is regarded as the first first induction heater, the fifth pyrometer V is arranged at the output end of the last first induction heater. Similarly, the eighth pyrometer VIII is arranged at the output end of the last second induction heater.

[0034] It can be understood that the first pyrometer I is used to measure the heating temperature of the strip steel; the second pyrometer II is used to measure the soaking temperature of the strip steel; the third pyrometer III is used to measure the slow cooling temperature of the strip steel; the fourth pyrometer IV is used to measure the first fast cooling temperature of the strip steel; the fifth pyrometer V is used to measure the first induction heating temperature of the strip steel; the sixth pyrometer VI is used to measure the first aging temperature of the strip steel; the seventh pyrometer VII is used to measure the second fast cooling temperature of the strip steel; the eighth pyrometer VIII is used to measure the second induction heating temperature of the strip steel; and the ninth pyrometer IX is used to measure the second aging temperature of the strip steel.

[0035] In some embodiments, the continuous annealing device can further comprise: a post-aging section connected to the outlet of the second aging section 7, the post-aging section comprising a final cooling section, a water quenching section, an outlet looper, and a skin pass mill, or the post-aging section comprising a third induction heater, a zinc pot, a post-plating cooling section, a water quenching section, an outlet looper, and a skin pass mill.

[0036] It can be understood that the continuous annealing device can be used in both a continuous annealing line and a galvanizing line. When used in the continuous annealing line, the post-aging section can comprise a final cooling section, a water quenching section, an outlet looper, and a skin pass mill. When used in the galvanizing line, the post-aging section can comprise a third induction heater, a zinc pot, a post-plating cooling section, a water quenching section, an outlet looper, and a skin pass mill.

[0037] The continuous annealing device of the embodiments of the present disclosure increases the second fast cooling section and the second aging section after the aging section of the conventional annealing production line, so that the elongation of the strip steel after annealing treatment is significantly improved, and the hole expansion rate is also improved, and thus the formability is significantly improved. The continuous annealing device can produce DP steel, QP steel and other steel grades according to the existing annealing process, or can produce the third generation of high-strength steel with higher elongation by using a new annealing process.

[0038] FIG. 6 shows a flowchart of a continuous annealing method according to some embodiments of the present disclosure. As shown in FIG. 6, a continuous annealing method is provided and applied to the continuous annealing device described above. In some embodiments, the continuous annealing method can comprise the following steps:

[0039] Step 601, controlling the heating section to perform heating treatment on the strip steel;

[0040] Step 602, controlling the soaking section to perform heat preservation treatment on the strip steel after the heating treatment;

[0041] Step 603, controlling the slow cooling section to perform first cooling treatment on the strip steel after the heat preservation treatment at a first cooling speed;

[0042] Step 604, controlling the first fast cooling section to perform second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed;

[0043] Step 605, controlling the first aging section to perform first aging treatment on the strip steel after the second cooling treatment;

[0044] Step 606, controlling the second fast cooling section to perform third cooling treatment on the strip steel after the first aging treatment at a third cooling speed; and

[0045] Step 607, controlling the second aging section to perform second aging treatment on the strip steel after the third cooling treatment, the second cooling speed and the third cooling speed being greater than the first cooling speed.

[0046] It can be understood that the production processes of different steel grades are different, and the controls of the first aging section, the second fast cooling section and the second aging section are also different. How to control the continuous annealing device to meet the production process requirements of different steel grades will be introduced below.

[0047] Figure 5 shows a schematic diagram of the production process applied to the continuous annealing device in Figure 4. As shown in Figure 5, mode one is the production process of DP steel, mode two is the production process of QP steel, and mode three and mode four are the production processes of the third generation of high-strength steel with higher formability. In these production processes, Ac1 is the start temperature of the transformation of pearlite to austenite during heating, Ac3 is the end temperature of the transformation of proeutectoid ferrite to austenite during heating, and Ms is the start temperature of the transformation of martensite during quenching.

[0048] For the production process of DP steel, in steps 604 to 607, the first fast cooling fan can be turned on to perform second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed; the first induction heater can be turned off, and the first radiation pipe or the first cooling air pipe can be controlled to perform first aging treatment on the strip steel after the second cooling treatment; and the second fast cooling fan and the second induction heater can be turned off, and the second radiation pipe or the second cooling air pipe can be controlled to perform second aging treatment on the strip steel after the first aging treatment.

[0049] In this production process, the heating temperature, the soaking temperature and the slow cooling temperature are consistent with the corresponding temperatures in the existing production process of DP steel, the first fast cooling temperature is the same as the fast cooling temperature in the existing production process of DP steel, the first aging temperature and the second aging temperature are the same as the aging temperature in the existing production process of DP steel, and the first induction heater in the first aging section, the second fast cooling fan in the second fast cooling section and the second induction heater in the second aging section are all turned off.

[0050] For the production process of QP steel, in steps 604 to 607, the first fast cooling fan can be turned on to perform second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed; the first induction heater can be turned on, and the first radiation pipe or the first cooling air pipe can be controlled to perform first aging treatment on the strip steel after the second cooling treatment; and the second fast cooling fan and the second induction heater can be turned off, and the second radiation pipe or the second cooling air pipe can be controlled to perform second aging treatment on the strip steel after the first aging treatment.

[0051] In this production process, the heating temperature, the soaking temperature and the slow cooling temperature are consistent with the corresponding temperatures in the existing production process of QP steel, the first fast cooling temperature is the same as the fast cooling temperature in the existing production process of QP steel, the first aging temperature and the second aging temperature are the same as the aging temperature in the existing production process of QP steel, and the second fast cooling fan in the second fast cooling section and the second induction heater in the second aging section are all turned off.

[0052] For the production process of the third generation high-strength steel with higher formability, in steps 604 to 607, the first fast cooling fan can be turned on to perform a second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed; the first induction heater can be turned on or off, and the first radiation pipe or the first cooling air pipe can be controlled to perform a first aging treatment on the strip steel after the second cooling treatment; the second fast cooling fan can be turned on to perform a third cooling treatment on the strip steel after the first aging treatment at a third cooling speed; and the second induction heater can be turned on, and the second radiation pipe or the second cooling air pipe can be controlled to perform a second aging treatment on the strip steel after the third cooling treatment.

[0053] In the production process shown in mode three, the strip steel passes through the heating section, the soaking section and the slow cooling section, and then enters the first fast cooling section, and the first fast cooling fan, the first induction heater, the second fast cooling fan and the second induction heater are all turned on.

[0054] In the production process shown in mode four, the strip steel passes through the heating section, the soaking section and the slow cooling section, and then enters the first fast cooling section, and the first fast cooling fan, the second fast cooling fan and the second induction heater are all turned on, and the first induction heater is turned off.

[0055] The continuous annealing method of the embodiments of the present disclosure can be used to produce DP steel, QP steel and other steel grades, and can also be used to produce the third generation high-strength steel with higher elongation, and has good compatibility and practicability.

[0056] The following is an application embodiment of the continuous annealing device involved in the present disclosure:

[0057] The conventional 780TR and 980TR slabs are hot charged into the furnace after being cleaned by the machine, the slab heating temperature is set to 1150-1250℃, the finish rolling temperature is set to 900℃, and the coiling temperature is set to 250℃, to obtain a hot-rolled plate.

[0058] The chemical composition of the slab can be seen in Table 1 below, wherein 1# is 780TR and 2# is 980TR.

[0059] The slab heating temperature is set to 1150-1250℃ to homogenize the structure and to solid-solve the micro-alloying elements. If the temperature is too high, it may cause abnormal grain growth, and if the temperature is too low, it may cause uneven composition and structure and insufficient solid-solution of the micro-alloying elements.

[0060] The finish rolling temperature is set to 900℃ to ensure that a good hot-rolled structure is obtained. If the finish rolling temperature is too high, the grains may become coarse, and if the finish rolling temperature is too low, mixed grains may appear.

[0061] The coiling temperature is set to 600℃ for rolling convenience, and a too high coiling temperature will adversely affect the surface control of the finished product.

[0062] The hot-rolled plate obtained by the above treatment is pickled to obtain a strip, and the strip is annealed by using the above continuous annealing device. The annealing process parameters and mechanical properties are shown in Table 2.

[0063] Examples 1-10 correspond to 1# 780TR slab. Example 1 corresponds to the production process of DP steel on the continuous annealing line, and the yield strength and tensile strength of the strip after annealing treatment meet the performance requirements of DP780. Example 2 corresponds to the production process of TRIP steel on the continuous annealing line, and the yield strength and tensile strength of the strip after annealing treatment meet the requirements of TRIP780. Example 3 corresponds to the production process of MS steel on the continuous annealing line, and the performance of the strip after annealing treatment meets the requirements of MS1100. Example 4 also corresponds to the production process of MS steel on the continuous annealing line, and the difference from Example 3 is that the second rapid cooling section and the second aging section are bypassed, the aging time is shortened, and the tensile strength of the strip after annealing treatment is slightly higher than that of Example 3. Example 5 corresponds to the production process of QP steel on the continuous annealing line, and compared with Example 2, the yield strength and tensile strength of the strip after annealing treatment have little difference, but the elongation is increased to 22.3%, and the hole expansion rate is also significantly improved. Example 6 corresponds to the process mode three on the continuous annealing line, and in this example, the first rapid cooling fan, the second rapid cooling fan, the first induction heater and the second induction heater are all turned on. Compared with Example 5, the yield strength and tensile strength of the strip after annealing treatment are basically the same, but the elongation is significantly improved to 27%, and the hole expansion rate is also improved to a certain extent, which indicates that the formability of the strip is significantly improved. Example 7 shortens the aging time of the first aging section and the second aging section based on Example 6, and the elongation of the strip after annealing treatment decreases slightly. Example 8 corresponds to the production process of QP steel on the galvanizing line. Example 9 is the application of the continuous annealing method according to some embodiments of the disclosure on the galvanizing line, and compared with Example 8, the elongation of the strip after annealing treatment is significantly improved, and the change rule of the elongation is basically the same as that in the application of the continuous annealing line. Example 10 corresponds to the process mode four on the continuous annealing line, and in this example, the first rapid cooling fan, the second rapid cooling fan and the second induction heater are turned on. Compared with Example 5, the elongation of the strip after annealing treatment is also significantly improved, and the hole expansion rate is also improved.

[0064] Examples 11-20 correspond to the production of 2#980TR strip. Example 11 corresponds to the production of DP steel on a continuous annealing line, under which the yield strength and tensile strength of the annealed strip meet the performance requirements of DP980. Example 12 corresponds to the production of TRIP steel on a continuous annealing line, under which the yield strength and tensile strength of the annealed strip meet the requirements of TRIP980, and the elongation is improved compared to Example 11. Example 13 corresponds to the production of MS steel on a continuous annealing line, under which the performance of the annealed strip meets the requirements of MS1180. Example 14 corresponds to the production of MS steel on a continuous annealing line, which is different from Example 13 in that the second rapid cooling section and the second aging section are bypassed, and the aging time is shortened. Example 15 corresponds to the production of QP steel on a continuous annealing line, compared to Example 11, the elongation of the annealed strip is increased to 18.5%, and the hole expansion rate is also significantly improved. Example 16 corresponds to the production of QP steel on a continuous annealing line according to mode three, compared to Example 15, the yield strength and tensile strength of the annealed strip are basically the same, but the elongation is significantly improved, and the hole expansion rate is also improved to a certain extent. Example 17 shortens the aging time of the first aging section and the second aging section based on Example 16, and the elongation of the annealed strip is slightly decreased. Example 18 corresponds to the production of QP steel on a galvanizing line. Example 19 is the application of the continuous annealing method according to some embodiments of the present disclosure on a galvanizing line, compared to Example 18, the elongation of the annealed strip is significantly improved, and the hole expansion rate is also improved. Example 20 corresponds to the production of QP steel on a continuous annealing line according to mode four, compared to Example 15, the elongation and hole expansion rate of the annealed strip are both improved.

[0065] From the above examples, it can be seen that the continuous annealing device and method according to the embodiments of the present disclosure can be used on a continuous annealing line or a galvanizing line, and can be used to produce existing high-strength steels (such as DP steel, TRIP steel, MS steel, QP steel, etc.) according to existing processes, or to produce third-generation high-strength steels with better formability according to new annealing processes (such as mode three and mode four).

[0066] The present disclosure also provides a continuous annealing device, which comprises a processor and a memory, the memory stores computer program instructions capable of being executed by the processor, and the processor implements the steps of the continuous annealing method described above when executing the computer program instructions.

[0067] The above only describes the embodiments of the present disclosure and is not intended to limit the present disclosure. Those skilled in the art can make various modifications and changes to the present disclosure. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present disclosure shall be included in the scope of the claims of the present disclosure.

Claims

1. A continuous annealing apparatus comprising: The heating section, the soaking section, the slow cooling section, the first fast cooling section, the first aging section, the second fast cooling section and the second aging section are sequentially arranged; wherein The heating section is configured to perform heating treatment on the strip steel. The soaking section is configured to perform heat preservation treatment on the strip steel after the heating treatment. The slow cooling section is configured to perform first cooling treatment on the strip steel after the heat preservation treatment at a first cooling speed. The first fast cooling section is configured to perform second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed. The first aging section is configured to perform first aging treatment on the strip steel after the second cooling treatment. The second fast cooling section is configured to perform third cooling treatment on the strip steel after the first aging treatment at a third cooling speed. The second aging section is configured to perform second aging treatment on the strip steel after the third cooling treatment, and the second cooling speed and the third cooling speed are both greater than the first cooling speed.

2. The continuous annealing apparatus according to claim 1, wherein The first fast cooling section comprises a first fast cooling fan, the first aging section comprises a first induction heater, a first radiation tube and a first cooling air pipe, the second fast cooling section comprises a second fast cooling fan, and the second aging section comprises a second induction heater, a second radiation tube and a second cooling air pipe; wherein The first radiation tube and the first cooling air pipe are arranged between the first induction heater and the second fast cooling fan; and The second radiation tube and the second cooling air pipe are arranged between the second induction heater and a post-aging equipment.

3. The continuous annealing apparatus according to claim 2, wherein The induction heating temperature range of the first induction heater is 0-800℃, the induction heating temperature range of the second induction heater is 0-500℃, and the cooling temperature range of the first fast cooling fan and the second fast cooling fan is both 0-800℃.

4. The continuous annealing apparatus according to claim 2, wherein The heating temperature range of the heating section is 0-950℃, the soaking time range of the soaking section is 0.5-5min, the cooling temperature range of the slow cooling section is 0-200℃, and the aging time range of the first aging section and the second aging section is both 0.1-15min.

5. The continuous annealing apparatus of claim 2, further comprising: A first pyrometer, a second pyrometer, a third pyrometer, a fourth pyrometer, a fifth pyrometer, a sixth pyrometer, a seventh pyrometer, an eighth pyrometer and a ninth pyrometer; wherein The first pyrometer is arranged at the outlet of the heating section; The second pyrometer is arranged at the outlet of the soaking section; The third pyrometer is arranged at the outlet of the slow cooling section; The fourth pyrometer is arranged at the outlet of the first fast cooling section; The fifth pyrometer is arranged at the output end of the first induction heater; The sixth pyrometer is arranged at the outlet of the first aging section; The seventh pyrometer is arranged at the outlet of the second fast cooling section; The eighth pyrometer is arranged at the output end of the second induction heater; and The ninth pyrometer is arranged at the outlet of the second aging section.

6. The continuous annealing apparatus of claim 1, further comprising: A post-aging equipment connected to the outlet of the second aging section, the post-aging equipment comprising a final cooling section, a water quenching section, an outlet loop and a skin pass mill, or the post-aging equipment comprising a third induction heater, a zinc pot, a post-plating cooling section, a water quenching section, an outlet loop and a skin pass mill.

7. A continuous annealing method applied to the continuous annealing device according to any one of claims 1 to 6, the continuous annealing method comprising: controlling the heating section to perform a heating treatment on the strip steel; controlling the soaking section to perform a soaking treatment on the strip steel after the heating treatment; controlling the slow cooling section to perform a first cooling treatment on the strip steel after the soaking treatment at a first cooling speed; controlling the first fast cooling section to perform a second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed; controlling the first aging section to perform a first aging treatment on the strip steel after the second cooling treatment; controlling the second fast cooling section to perform a third cooling treatment on the strip steel after the first aging treatment at a third cooling speed; and controlling the second aging section to perform a second aging treatment on the strip steel after the third cooling treatment, the second cooling speed and the third cooling speed being greater than the first cooling speed. the first fast cooling section comprises a first fast cooling fan, the first aging section comprises a first induction heater, a first radiation tube and a first cooling air pipe, the second fast cooling section comprises a second fast cooling fan, the second aging section comprises a second induction heater, a second radiation tube and a second cooling air pipe, after the controlling the slow cooling section to perform a first cooling treatment on the strip steel after the soaking treatment at a first cooling speed, the continuous annealing method further comprises:

8. The continuous annealing method according to claim 7, wherein, turning on the first fast cooling fan to perform a second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed; turning on or off the first induction heater and controlling the first radiation tube or the first cooling air pipe to perform a first aging treatment on the strip steel after the second cooling treatment; turning on the second fast cooling fan to perform a third cooling treatment on the strip steel after the first aging treatment at a third cooling speed; and turning on the second induction heater and controlling the second radiation tube or the second cooling air pipe to perform a second aging treatment on the strip steel after the third cooling treatment. the first fast cooling section comprises a first fast cooling fan, the first aging section comprises a first induction heater, a first radiation tube and a first cooling air pipe, the second fast cooling section comprises a second fast cooling fan, the second aging section comprises a second induction heater, a second radiation tube and a second cooling air pipe, after the controlling the slow cooling section to perform a first cooling treatment on the strip steel after the soaking treatment at a first cooling speed, the continuous annealing method further comprises:

9. The continuous annealing method of claim 8, wherein, turning on the first fast cooling fan to perform a second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed; turning off the first induction heater and controlling the first radiation tube or the first cooling air pipe to perform a first aging treatment on the strip steel after the second cooling treatment; and turning off the second fast cooling fan and the second induction heater and controlling the second radiation tube or the second cooling air pipe to perform a second aging treatment on the strip steel after the first aging treatment. the first fast cooling section comprises a first fast cooling fan, the first aging section comprises a first induction heater, a first radiation tube and a first cooling air pipe, the second fast cooling section comprises a second fast cooling fan, the second aging section comprises a second induction heater, a second radiation tube and a second cooling air pipe, after the controlling the slow cooling section to perform a first cooling treatment on the strip steel after the soaking treatment at a first cooling speed, the continuous annealing method further comprises: turning on the first fast cooling fan to perform a second cooling treatment on the strip steel after the first cooling treatment at a second cooling speed; turning off the first induction heater and controlling the first radiation tube or the first cooling air pipe to perform a first aging treatment on the strip steel after the second cooling treatment; and turning off the second fast cooling fan and the second induction heater and controlling the second radiation tube or the second cooling air pipe to perform a second aging treatment on the strip steel after the first aging treatment.

10. The continuous annealing method of claim 7, wherein, The first fast cooling section comprises a first fast cooling fan, the first aging section comprises a first induction heater, a first radiation tube and a first cooling air pipe, the second fast cooling section comprises a second fast cooling fan, the second aging section comprises a second induction heater, a second radiation tube and a second cooling air pipe, after the strip steel after the heat preservation treatment is cooled at the first cooling speed by the control slow cooling section, the continuous annealing method further comprises: the first fast cooling fan is turned on to cool the strip steel after the first cooling treatment at a second cooling speed for a second time; the first induction heater is turned on, and the first radiation tube or the first cooling air pipe is controlled to age the strip steel after the second cooling treatment for a first time; and the second fast cooling fan and the second induction heater are turned off, and the second radiation tube or the second cooling air pipe is controlled to age the strip steel after the first aging treatment for a second time.

11. A continuous annealing apparatus comprising a processor and a memory, wherein, The memory stores computer program instructions capable of being executed by the processor, and the processor executes the computer program instructions to realize the steps of the method in any one of claims 7 to 10.

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