JP4810732B2 - Steel plate thermomechanical processing equipment - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a thick steel plate thermomechanical processing apparatus capable of efficiently heat-treating an accelerated cooled thick steel plate on-line efficiently after hot rolling.
[0002]
[Prior art]
A thick steel plate is manufactured by rolling a slab heated to a predetermined temperature in a heating furnace with a hot rolling mill, cooling to room temperature, and then cutting to a predetermined dimension. In recent years, in order to increase the strength and toughness of thick steel plates, a cooling device is provided on the outlet side of the hot rolling mill to accelerate cooling the thick steel plates rolled by the hot rolling mill, and after accelerated cooling A thick steel plate is heat-treated in a heat treatment furnace. Conventionally, since heat treatment is performed in a heat treatment furnace installed offline, there is a problem that a manufacturing period is required, mass production cannot be performed, and manufacturing efficiency is poor. In recent years, a method of efficiently performing a heat treatment by installing a heat treatment furnace on a rolling to shear line has been proposed.
The literature regarding the heat processing of the conventional thick steel plate is shown below.
[0003]
A rapid heating tempering process is performed by a heating device installed on the same line as the rolling mill and the accelerated cooling device. The purpose of this treatment is to improve work efficiency and toughen the steel sheet. As the heating method, current heating or infrared radiation heating is used (hereinafter referred to as “prior art 1”).
[0004]
JP, 6-134512, A The cooling bed {cooling bed (CB)} and a heat treatment furnace are arranged near, and the exit side of a heat treatment furnace and the entrance side of CB are directly connected with a transfer line. According to this, continuous processing of heat treatment and shearing is enabled online (hereinafter referred to as “prior art 2”).
[0005]
JP, 6-254615, A Hot straightening machine, a cooling device, and a heat retention device are arranged in this order, and a steel plate excellent in shape is obtained by keeping the steel plate at a constant temperature with the heat retention device and making the temperature distribution on the inner surface of the steel plate uniform. (Hereinafter referred to as “prior art 3”).
[0006]
Japanese Patent Application Laid-Open No. 2000-119744 is an application filed by the applicant of the present application, and performs online dehydrogenation using a heat treatment apparatus arranged in parallel on a rolling line. As an embodiment, it is a configuration with a layout in which an online hot cutting machine and a heat treatment apparatus are arranged on a line (hereinafter referred to as “prior art 4”).
[0007]
[Problems to be solved by the invention]
However, in recent years, the rolling pitch (time interval) of thick steel plates in the rolling mill has been shortened to a short time of about 2.5 to 3 minutes in order to improve the rolling capacity of the rolling mill. Therefore, in order to adapt the heat treatment to such a pitch, the prior art has the following problems.
[0008]
In Prior Art 1, no specific disclosure is made about the equipment layout in actual manufacturing. If the facilities are arranged on the same line as in the embodiment, there is a problem that an imbalance between the rolling efficiency and the heat treatment efficiency occurs. In addition, the heat treatment of a steel plate having a total length of 40 to 50 m requires an enormous scale of equipment suitable for it, and it is unrealistic and impossible to install it.
[0009]
Prior art 2 does not disclose any equipment layout in the upper process than the heat treatment furnace. That is, heat treatment is substantially impossible in a layout that does not have a hot cutter.
[0010]
In the prior art 3, as in the prior art 1, the processing on the same line cannot be realized.
[0011]
Prior art 4 does not have accelerated cooling equipment.
[0012]
As described above, in order to efficiently heat and heat a thick steel plate that has been rolled and accelerated and cooled, it is desirable to provide a heat treatment furnace on-line. However, no technology that can solve the problem has been developed yet.
[0013]
Accordingly, an object of the present invention is to solve the above-mentioned problems and to provide a thick steel plate work heat treatment apparatus capable of efficiently heat-treating the accelerated and cooled thick steel plate after hot rolling.
[0014]
[Means for Solving the Problems]
As a result of intensive research to solve the above problems, we have newly obtained the following knowledge. That is, a heat treatment facility capable of rapid heating is preferable in order to heat-treat a thick steel plate manufactured by the accelerated cooling facility in large quantities efficiently online. Moreover, in order to make it a realistic heat treatment furnace, it is necessary to cut the rolled steel plate before the heat treatment. Furthermore, in order to eliminate the imbalance between the rolling efficiency and the heat treatment efficiency, a buffer such as a cooling bed is required. The present invention has been made based on the above findings.
[0015]
According to the first aspect of the present invention , an accelerated cooling device , a hot straightening machine , a hot cutting machine, and a downstream side of the hot cutting machine, which are sequentially provided along the rolling line on the exit side of the rolling mill. The cooling which has the 1st conveyance line provided in parallel with the downstream rolling line of this, and the 2nd conveyance line and the 3rd conveyance line provided between the downstream rolling line and the 1st conveyance line A heat treatment furnace provided in the vicinity of the floor and the cooling bed, rolled by the rolling mill, accelerated and cooled by the accelerated cooling device, and corrected by the hot straightening machine, and then the hot cutting The steel plate cut by the machine is transported from the downstream rolling line to the first transport line via the second transport line while being cooled in the cooling bed, and then passes through the third transport line. To the downstream rolling line Then, after being transported to the heat treatment furnace and heated in the process of moving in the heat treatment furnace in one direction, the cooling bed is cooled from the first transport line through the third transport line. It is transported to the downstream rolling line, and is transported to the next process by the downstream rolling line without passing through the heat treatment furnace .
[0016]
The invention according to claim 2 is an accelerated cooling device, a hot straightening machine, a hot cutting machine, and a downstream side of the hot cutting machine, which are sequentially provided along the rolling line on the exit side of the rolling mill. The cooling which has the 1st conveyance line provided in parallel with the downstream rolling line of this, and the 2nd conveyance line and the 3rd conveyance line provided between the downstream rolling line and the 1st conveyance line A heat treatment furnace provided adjacent to the cooling bed and following the first transfer line, rolled by the rolling mill, accelerated by the accelerated cooling device, and corrected by the hot straightening machine Then, the thick steel plate cut by the hot cutting machine is transferred to the first transfer line via the second transfer line while being cooled by the cooling bed from the downstream rolling line, Conveyed to the heat treatment furnace, After being heat-treated in the process of reciprocating in the processing furnace, it is transported to the downstream rolling line via the third transport line while being cooled in the cooling bed, and then the next step by the downstream rolling line It is characterized by being conveyed to
[0017]
The invention according to claim 3 is characterized in that, in the invention according to claim 1 or 2, the heat treatment furnace is a high-frequency induction heating furnace, and the invention according to claim 4 is the invention according to claim 1. Alternatively , in the invention described in 2, the heat treatment furnace is a tempering furnace, and the tempering furnace is a high frequency induction heating furnace.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Next, embodiments of the present invention will be described with reference to the drawings.
[0019]
[Embodiment 1]
FIG. 1 is a perspective view showing the arrangement of devices according to the first embodiment of the present invention, and FIG. 2 is a plan view.
[0020]
As shown in FIGS. 1 and 2, in the hot rolling line 9, the accelerated cooling device 2 and the hot straightening machine are arranged in order from the upstream side of the rolling line 9 along the rolling line 9 on the exit side of the rolling mill 1. 12, a hot cutting machine 3 and a cooling bed (cooling bed) 4 are provided, and a heat treatment furnace (high-frequency induction heating furnace) 5 is provided in the vicinity of the cooling bed 4. The high frequency induction heating furnace 5 is arranged on the downstream side of the cooling bed 4 and shifted to the side surface side of the rolling line 9. The downstream of the high frequency induction heating furnace 5 is a shearing process 6.
[0021]
A transfer 7 is provided on the downstream side of the high-frequency induction heating furnace 5 adjacent to the inlet 5 a of the heating furnace 5. The transfer 7 has a function of carrying the thick steel plate 11 from the rolling line 9 to the inlet 5 a of the heating furnace 5 and further inserting it into the heating furnace 5. Furthermore, a transfer 8 is provided at the outlet 5 b of the heating furnace 5 adjacent to the outlet 5 b of the heating furnace 5. The transfer 8 has a function of carrying out the thick steel plate 11 heated by the heating furnace 5 from the outlet 5 b of the heating furnace 5 and carrying it to the conveyance line 10. The conveyance line 10 is provided in parallel with the rolling line 9 and conveys the heat-treated thick steel plate 11 from the exit side of the transfer 8 to the cooling bed 4.
[0022]
The cooling floor 4 includes a transport line 41 that transports the thick steel plate 11 to the transport line 10 in a direction orthogonal to the rolling line 9, and a transport line 42 that transports the thick steel plate 11 from the transport line 10 to the rolling line 9.
[0023]
The accelerated cooling device 2 is a device that accelerates and cools a thick steel plate by water spray or jet flow, and can use an apparatus such as a normal roller quench or a pressure quench. The hot straightening machine 12 is not particularly limited as long as it can correct the strain after rolling and accelerated cooling, and a normal hot straightening machine can be used.
[0024]
The type of the hot cutting machine 3 is not particularly limited as long as it does not affect the rolling pitch, and a normal shearing machine can be used.
[0025]
By using the high-frequency induction heating device 5 capable of rapid heating as the heat treatment furnace, a heat treatment efficiency equivalent to the rolling / shear line efficiency can be obtained. This heat treatment furnace is used as a tempering furnace, and is used for the purpose of adjusting the material and removing residual stress.
[0026]
[Action]
After rolling by the rolling mill 1, the thick steel plate 11 that has been accelerated and cooled by the accelerated cooling device 2, corrected by the hot straightening machine 12, and then cut by the hot cutting machine 3 is transferred to the conveying line 41 in the cooling floor 4. It is conveyed and cooled by 42 over a predetermined time. Next, the thick steel plate 11 that has arrived at the transfer line 9 is transferred to the transfer 7 by the transfer line 9, and is inserted into the heating furnace 5 from the inlet 5 a of the heating furnace 5 by the transfer 7. Next, the thick steel plate 11 heat-treated in the heating furnace 5 is transported from the outlet 5 b of the heating furnace 5 to the cooling bed 4 by the ton lance fur 8 and the transport line 10. Then, it is conveyed again to the conveyance line 9 by the conveyance line 42. Subsequently, it is conveyed by the conveyance line 9 to the shearing process 6 without going through the heating furnace 5 this time. The arrows shown in FIGS. 1 and 2 indicate the movement of the thick steel plate. In FIG. 2, the arrows in the cooling bed 4 and the rolling line 9 indicate that the thick steel plate passes through the place twice.
[0027]
The speed of the conveying lines 41 and 42 of the cooling bed 4 can be adjusted, and the speed is adjusted according to the rolling pitch (rolling efficiency) and the processing capacity (heat treatment efficiency) of the heating furnace 5 to balance the rolling efficiency and the heat treatment efficiency. Can keep. According to the thermomechanical processing apparatus of the present invention described above, a large amount of heat treatment can be performed without reducing productivity.
[0028]
[Embodiment 2]
FIG. 3 is a plan view showing the arrangement of the devices according to the second embodiment of the present invention. As shown in FIG. 3, along the rolling line 9, a rolling mill 1 (not shown), an accelerated cooling device 2 (not shown), a hot straightening machine 12 (not shown), a hot cutting machine 3, A cooling bed 4 is provided. The high-frequency induction heating furnace 5 is disposed on an extension of the transfer line 10 provided along with the cooling bed 4, and the thick steel plates on the transfer line 10 are inserted into and out of the heating furnace 5 at the entrance / exit 5 c of the heating furnace 5.・ It can be taken out.
[0029]
[Action]
After rolling by the rolling mill 1, the thick steel plate 11 accelerated and cooled by the acceleration cooling device 2 and hot cut by the hot cutting machine 3 is conveyed on the cooling bed 4 by a conveying line 41 over a predetermined time. . Once transported to the transport line 10, the thick steel plate 11 is inserted into the heating furnace 5 through the entrance / exit 5c. Next, the thick steel plate 11 heat-treated in the heating furnace 5 is carried out from the inlet / outlet 5 c to the conveying line 10, and is conveyed to the conveying line 9 by the conveying line 42. Subsequently, it is conveyed by the conveyance line 9 to a shearing process. The arrows shown in FIG. 3 indicate the movement of the thick steel plate.
[0030]
【Example】
Next, examples of the present invention will be described.
[0031]
In the first example, a thick steel plate was manufactured by the apparatus shown in the first embodiment (FIGS. 1 and 2). As a result, the heat treatment could be carried out quickly by providing the heat treatment furnace close to the cooling bed. Further, since a high-frequency induction heating furnace is arranged as a heat treatment furnace, the heat treatment time in the heat treatment furnace was about 3 minutes when tempering heat treatment of a 20 mm thick plate. As described above, the heat treatment time can be greatly shortened by using the high frequency induction heating furnace. All the heat-treated steel sheets were subsequently cut to a predetermined size by a shear line.
[0032]
Further, as a comparative example, tempering treatment was performed using a gas heating furnace installed off-line as before. In this case, it is necessary to convey to a gas heating furnace using means, such as a conveyance line or a crane. In this example, it took about 40 minutes for the tempering heat treatment of the 20 mm thick material, and the production efficiency was lowered. Moreover, it is necessary to convey to the shear line after heat processing. Since normal rolling material was sheared in the shearing line, the waiting time for shearing occurred and the manufacturing period was significantly increased.
[0033]
【The invention's effect】
As described above, according to the present invention, the following useful effects are brought about.
(1) By placing the heat treatment furnace close to the cooling bed, the accelerated cooled steel sheet can be continuously heat treated online, compared to the conventional offline where the heat treatment must be performed once off the line. As a result, work efficiency is improved, and a large amount of heat treatment can be performed efficiently without reducing productivity.
(2) By using a high-frequency induction heating apparatus capable of rapid heating as the heat treatment furnace, the heat treatment time can be shortened, and the working efficiency can be further improved.
(3) Since a hot cutting machine is provided on the exit side of the rolling mill, the rolled thick steel plate is cut to a length close to the final product before heat treatment in the heat treatment furnace, and then into the heat treatment furnace. since being inserted, it is possible to shorten the length of Netsusho sense furnace can be installed in-line.
(4) Since the thick steel plate is conveyed over a predetermined time in the cooling bed, the time can be extended to several times the rolling pitch, and the heat treatment of the thick steel plate can be balanced between the rolling efficiency and the heat treatment efficiency. It can be done without inhibition.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the arrangement of devices according to a first embodiment of the present invention.
FIG. 2 is a plan view showing the arrangement of devices according to the first embodiment of the present invention.
FIG. 3 is a plan view showing the arrangement of devices according to a second embodiment of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Rolling machine 2 Accelerated cooling device 3 Hot cutting machine 4 Cooling bed (cooling bed)
41, 42 Conveyance line 5 Heat treatment furnace (high frequency induction heating furnace)
5a Inlet 5b Outlet 5c In / out 6 Shearing process 7 Transfer 8 Transfer 9 Rolling line 10 Conveying line 11 Thick steel plate 12 Hot straightening machine

Claims (4)

An accelerating cooling device , a hot straightening machine , a hot cutting machine, and a downstream rolling line on the downstream side of the hot cutting machine are sequentially provided along the rolling line on the exit side of the rolling mill. Close to the cooling bed, which is provided between the first conveying line provided, the second rolling line and the third conveying line, which is provided between the downstream rolling line and the first conveying line. A thick steel plate that is rolled by the rolling mill, accelerated by the accelerated cooling device, corrected by the hot straightening machine, and then cut by the hot cutting machine. , While being cooled in the cooling bed from the downstream side rolling line, and conveyed to the first conveying line via the second conveying line, and then to the downstream rolling line via the third conveying line Then the heat treatment After being transported to a furnace and heated in the course of moving in the heat treatment furnace in one direction, the downstream rolling line passes through the third transport line while being cooled by the cooling bed from the first transport line. Then, the steel plate is conveyed to the next step by the downstream rolling line without passing through the heat treatment furnace, and is a heat treatment apparatus for thick steel plates. An accelerating cooling device, a hot straightening machine, a hot cutting machine, and a downstream rolling line on the downstream side of the hot cutting machine are sequentially provided along the rolling line on the exit side of the rolling mill. Close to the cooling bed, which is provided between the first conveying line provided, the second rolling line and the third conveying line, which is provided between the downstream rolling line and the first conveying line. And a heat treatment furnace provided subsequent to the first transfer line, rolled by the rolling mill, accelerated and cooled by the accelerated cooling device, corrected by the hot straightening machine, and then hot-cut. The steel plate cut by the machine is transported to the first transport line via the second transport line while being cooled in the cooling bed from the downstream rolling line, and then transported to the heat treatment furnace, Move back and forth in the heat treatment furnace After being heated in the process, characterized in that the cooling bed in via the third transport line while being cooled is conveyed in the downstream rolling line, and is conveyed to the next process by the downstream rolling line A processing heat treatment apparatus for thick steel plates. The apparatus for heat treatment of thick steel plate according to claim 1 or 2, wherein the heat treatment furnace is a high frequency induction heating furnace. The apparatus for heat treatment of thick steel plates according to claim 1 or 2, wherein the heat treatment furnace is a tempering furnace, and the tempering furnace is a high frequency induction heating furnace.

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