Roll changing method for a continuous casting and rolling line rolling mill

Abstract

The application provides a rolling mill roll changing method of a continuous casting and rolling production line, and relates to the technical field of metallurgical continuous casting and rolling, and comprises the following steps: calculating a working roll replacement time according to a production planning system, the calculation being completed in a endless mode, four slab blanks being output in a single block mode in order to provide sufficient buffer time for working roll replacement, and the output quantity of the single block being changed according to the actual production of the single block mode to provide sufficient roll replacement buffer time. The application can realize continuous casting and rolling of the continuous casting-tunnel furnace-rolling mill mode without stopping casting and replacing the roll, the roll replacement process does not need to remove the slab, can avoid causing slab waste, improves the yield, reduces the production cost, and improves the benefit; when there is a quality problem such as scratch on the surface of the strip steel, the application provides an operation method to free up time to deal with the problem, avoids stopping casting and removing the slab, improves the production line operation rate and the yield, reduces the production cost, and improves the benefit.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgical continuous casting and rolling, in particular to a rolling mill roll changing method for a continuous casting and rolling production line. BACKGROUND

[0002] In the continuous casting and rolling production, low cost is one of the main competitive advantages of the continuous casting and rolling production line, and long casting production is of great significance to improve the operation rate of the production line and reduce the production cost. At present, with the continuous improvement of the quality of refractory materials, the single casting production of 900 min has become a reality, and the longest roll period of the rolling mill is about 500 min, which is equivalent to 260 km. The roll period has become the main contradiction of long casting production. With the adoption of the continuous casting-tunnel furnace-rolling mill mode, the continuous casting and rolling production line can realize single casting multi-roll production. When the rolling mill changes the work roll, the caster does not stop casting, and two short plate blanks are produced to remove the tunnel furnace to provide buffer time for the rolling mill to change the work roll.

[0003] However, the removed plate blanks, whether reheated for rolling or directly discarded, still cause great waste, reduce the yield of the production line, increase the overall production cost, and reduce the competitiveness of the production line. SUMMARY

[0004] The purpose of the present application is to provide a rolling mill roll changing method for a continuous casting and rolling production line, which has the beneficial effects of not needing to stop casting and removing blanks during the roll changing process, avoiding plate blank waste, improving yield, reducing production cost, and improving efficiency, to solve the problems raised in the background art.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0006] A rolling mill roll changing method for a continuous casting and rolling production line, the roll changing method comprising the following steps:

[0007] According to the production planning system, a work roll changing time is calculated, which is completed in a headless mode. In order to provide sufficient buffer time for the work roll changing, four plate blanks are produced in a single block mode, and the number of single blocks is changed according to the actual production situation of the single block mode to provide sufficient roll changing buffer time.

[0008] As a further scheme of the present application: the roll changing method comprises the following steps:

[0009] The headless mode is stopped, and the separation of the caster and the rolling mill is defined after the shearing of the shearing machine.

[0010] As a further scheme of the present application: the roll changing method comprises the following steps:

[0011] The rolling mill is accelerated to roll at a speed of more than twice the speed of the caster, and the rolling speed of the headless plate blank in the furnace is increased by increasing the outlet temperature of the finishing mill.

[0012] As a further scheme of the present application: the roll changing method comprises the following steps:

[0013] After the headless interruption, the casting machine reduces the pulling speed to 3-4 m / min, and three slabs are output to supply the rolling mill for rolling, and the casting machine adjusts the cooling water of the crystallizer and the secondary cooling water distribution to ensure that the surface temperature of the casting slab is greater than 950℃ at the pulling speed.

[0014] As a further scheme of the present application: the roll changing method comprises the following steps:

[0015] The rolling mill completes the rolling of three single blocks at a high speed, and the rolling mill increases the steel rhythm to gain buffer time for roll changing when rolling three single blocks, and after the rolling mill completes the rolling of the third single block, the casting machine is outputting the fourth single block to maximize the emptying of the furnace area, and there is 68-72 meters of slab space.

[0016] As a further scheme of the present application: the roll changing method comprises the following steps:

[0017] After the rolling mill completes the rolling of the third single block, the finishing mill changes the work roll, and the roll changing time is 10-15 min.

[0018] As a further scheme of the present application: the roll changing method comprises the following steps:

[0019] After the casting machine completes the continuous casting of the fourth single block, headless production is started, and the speed increasing operation is performed according to the roll changing progress of the finishing mill.

[0020] As a further scheme of the present application: the roll changing method comprises the following steps:

[0021] After the roll changing of the finishing mill is completed, the simulation production is performed by the combined coiling machine, the finishing mill rolls the strip, and the coiling machine coils the strip.

[0022] As a further scheme of the present application: the roll changing method comprises the following steps:

[0023] After the simulation production is completed, in order to heat the roll and find the appropriate level value, the rolling mill completes the rolling of the fourth slab, and waits for the headless strip threading.

[0024] As a further scheme of the present application: the roll changing method comprises the following steps:

[0025] After the headless strip threading is completed, the headless mode production is continued.

[0026] Compared with the prior art, the present application has the following beneficial effects:

[0027] 1. The application can realize continuous casting-continuous casting and rolling production line under the mode of continuous casting-continuous rolling, and the roll changing process does not need to remove the billet, which can avoid causing the waste of slab, improve the yield, reduce the production cost, and improve the benefit.

[0028] 2. When the quality problem such as scratch appears on the surface of the strip, the operation method provided by the application can be used to free up time to handle the problem point, avoid stopping pouring and removing the billet, improve the production line operation rate and the yield, reduce the production cost, and improve the benefit. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions in the embodiments of the application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the application, and other drawings can be obtained by those skilled in the art without creative labor.

[0030] In order to more completely understand the application and its beneficial effects, the following will be described with reference to the drawings. In the following description, the same reference numerals represent the same parts.

[0031] Figure 1 It is a schematic diagram of continuous casting and rolling production line.

[0032] Figure 2 It is Figure 1 A local enlarged view of A in FIG.

[0033] Figure 3 It is Figure 1 A local enlarged view of B in FIG.

[0034] Identified in the figure:

[0035] 1, casting machine; 2, swing shear; 3, tunnel furnace; 4, rough rolling mill; 5, finishing rolling mill; 6, high-speed flying shear; 7, coiling machine. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the application will be described clearly and completely with reference to the drawings in the embodiments of the application. Obviously, the described embodiments are only some of the embodiments of the application, not all. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the application.

[0037] Please refer to the drawings Figures 1 to 3 The embodiment of the application provides a continuous casting and rolling production line rolling mill roll changing method, which comprises the following steps:

[0038] The production planning system calculates the changeover time for a work roll. For example, if the plan is to produce 20 heats, the rolls are changed when the 10th heat is finished. To ensure rolling accuracy and product quality, this calculation is performed in headless mode. To provide sufficient buffer time for work roll changeover, headless mode refers to the continuous rolling process from the slab exiting the casting machine 1 until the rolling mill finishes rolling. To ensure rolling accuracy, the slabs between the casting machine 1 and the rolling mill are continuous until the coiler 7 coils the strip, at which point the high-speed flying shear 6 interrupts the strip rolling, thus stopping the headless mode. In single-slab mode, four slabs are produced. The number of slabs produced per slab is adjusted based on the actual production situation in single-slab mode to provide sufficient roll changeover buffer time. For example, if the production status of the casting machine 1 is good, producing three slabs in single-slab mode is sufficient to meet the roll changeover time. If the production status of the casting machine 1 is poor, five slabs need to be produced in single-slab mode to meet the roll changeover time. This application enables continuous casting and rolling production lines in the continuous casting-tunnel furnace-rolling mill mode to change rolls without interruption. The roll changing process does not require billet removal, which avoids billet waste, improves yield, reduces production costs, and increases efficiency. When quality problems such as scratches appear on the strip surface, the operation method provided in this application can free up time to deal with the problem, avoid stopping casting and billet removal, improve production line operation rate and yield, reduce production costs, and increase efficiency.

[0039] In a preferred embodiment of the present invention, the roller changing method includes the following steps:

[0040] The headless mode stops, and after the swing shear 2 cuts, the separation of the casting machine 1 and the rolling mill is defined. After the slab comes out of the casting machine 1, it is cut by the swing shear 2.

[0041] The rolling mill speed is increased to accelerate the rolling of the slab coming out of the casting machine 1. The rolling speed is more than twice that of the casting machine 1. The rolling speed of the endless slab in the furnace is increased by increasing the exit temperature of the finishing mill.

[0042] After the headless interruption, the casting machine 1 reduces the casting speed to 3-4 m / min, thereby reducing the billet speed. As a result, the distance between the billet and the rolling mill increases. The casting machine 1 produces three billets to supply the rolling mill for rolling. At the same time, the casting machine 1 adjusts the cooling water of the crystallizer and the secondary cooling water supply to ensure that the surface temperature of the billet is greater than 950°C at this casting speed. This can reduce the heating temperature required by the tunnel furnace 3 and save the fuel required for heating the tunnel furnace 3.

[0043] The rolling mill completes the rolling of three single blocks at high speed. When rolling the three single blocks, the rolling mill increases the steel demand rhythm to give the rolling mill roll change buffer time. After the rolling mill finishes rolling the third single block, the casting machine 1 is producing the fourth single block to maximize the emptying of the furnace area and ensure the maximum billet feeding space between the casting machine 1 and the rolling mill, with a billet feeding space of 68 to 72 meters.

[0044] The finishing mill 5 changes the work roll after the third single piece is finished, and the roll changing time is 10-15 minutes. If the roll changing time is exceeded during the roll changing of the mill, the slab can be removed by the caster 1 to buffer the roll changing time;

[0045] After the fourth single piece is continuously cast by the caster 1, the headless production is started, and the speed is increased according to the roll changing progress of the finishing mill 5;

[0046] After the roll changing of the finishing mill 5 is completed, the simulation production is performed by the combined coiler 7, the finishing mill 5 rolls the strip, and the coiler 7 winds the strip;

[0047] After the simulation production is completed, the fourth slab is rolled to find the suitable level value, and the headless strip is waited. Since the newly changed roll is cold, if the cold roll directly contacts the hot slab, the slab is unevenly expanded and contracted due to heat expansion and cold contraction, and the slab is deviated and the gap of the slab is increased. After the fourth slab is rolled by the mill, the newly changed roll can be preheated, and the deviated slab can be adjusted in time to avoid interference with the subsequent headless production and ensure the normal operation of the subsequent headless production.

[0048] After the headless strip is completed, the headless mode production is continued, that is, the slab between the caster 1 and the mill is not cut off, and the headless production is performed.

[0049] The application provides a roll changing method of a continuous casting and rolling production line. The method is applied to the continuous casting and rolling production line, and the continuous casting and rolling production line comprises a continuous casting machine 1, a flying shear 2, a tunnel furnace 3, a vertical roll, a rough rolling mill 4, a flying shear, a finishing mill 5, a laminar cooling channel, a high-speed flying shear 6 and a coiler 7. The continuous casting machine 1, the flying shear 2, the tunnel furnace 3, the vertical roll, the rough rolling mill 4, the flying shear, the finishing mill 5, the laminar cooling channel, the high-speed flying shear 6 and the coiler 7 are sequentially arranged. The production process of the continuous casting and rolling production line is as follows: the continuous casting machine 1 continuously casts a slab to the flying shear 2, the flying shear 2 can cut the slab, the slab is heated after being cut, the tunnel furnace 3 has the function of removing the slab, can buffer the roll changing time of the finishing mill 5, the slab is delivered to the vertical roll by the tunnel furnace 3, the vertical roll has the function of edge alignment, the spread of the horizontal rolled steel plate is compressed back to maintain the predetermined plate width, the slab is delivered to the rough rolling mill 4 by the vertical roll for rough rolling, the slab can be cut by the flying shear, then the slab is finished by the finishing mill 5, cooled by the laminar cooling channel and wound by the coiler 7, and the coiler 7 is cut by the high-speed flying shear 6 after winding.

[0050] The application can realize continuous casting and rolling of a continuous casting-tunnel furnace-3-rolling mill mode without stopping pouring and changing rollers, and the changing roller process does not need to remove the billet, can avoid causing waste of the slab, improves the material yield, reduces the production cost, improves the benefit, and can use the operation method provided by the application to leave time to deal with the problem point when there is a scratch on the surface of the strip and other quality problems, avoids stopping pouring and removing the billet, improves the production line operation rate and the material yield, reduces the production cost, and improves the benefit.

[0051] In the above embodiments, the description of each embodiment has its own focus, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0052] In the description of the application, the terms "first", "second" are only for the purpose of description, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined with "first", "second" can explicitly or implicitly include one or more features.

[0053] The principles and implementation modes of the application are described by applying specific examples herein, and the above description of the examples is only for helping to understand the method of the application and its core idea; meanwhile, for those skilled in the art, according to the idea of the application, the specific implementation mode and application range will have changes, and on the basis of the above, the content of the specification should not be understood as limiting the application.

Claims

1. A roll change method for a continuous-casting continuous-rolling production line, characterized by, The roll changing method comprises the following steps: The work roll changing time is calculated according to the production planning system, the calculation is completed in the endless mode, four slabs are produced in the single block mode in order to have enough buffer time for work roll changing, the number of single blocks produced is changed according to the actual production of the single block mode to provide enough roll changing buffer time; The roll changing method comprises the following steps: The rolling mill completes three single block rolling at high speed, the rolling mill increases the steel feeding rhythm to gain buffer time for work roll changing, after the third single block is rolled, the caster is continuously casting the fourth single block to maximize the emptying of the furnace area, and there is 68-72 meters of billet feeding space; The roll changing method comprises the following steps: After the third single block is rolled by the finishing mill, the work roll of the finishing mill is changed, and the roll changing time is 10-15 minutes.

2. A method of roll change in a continuous casting and rolling line according to claim 1, characterized in that, The roll changing method comprises the following steps: The endless mode is stopped, and the separation of the caster and the rolling mill is defined after the shearing of the decoiler.

3. A method of roll change in a continuous casting and rolling line according to claim 2, characterized in that, The roll changing method comprises the following steps: The rolling mill increases the rolling speed, and the rolling speed is more than twice the speed of the caster, and the rolling speed of the endless slab in the furnace is increased by increasing the outlet temperature of the finishing mill.

4. A roll changing method for a roll mill of a continuous casting and rolling line according to claim 3, characterized in that, The roll changing method comprises the following steps: After the interruption of the endless mode, the casting speed of the caster is reduced to 3-4 m / min, three slabs are produced to supply the rolling mill for rolling, and the mold cooling water and the secondary cooling water of the caster are adjusted to ensure that the surface temperature of the casting slab is greater than 950 DEG C at this casting speed.

5. A roll changing method for a continuous-casting continuous-rolling production line according to claim 1, characterized in that, The roll changing method comprises the following steps: After the fourth single block is continuously cast by the caster, the endless production is started, and the casting speed is increased according to the roll changing progress of the finishing mill.

6. A roll changing method for a roll mill of a continuous casting and rolling line according to claim 5, characterized in that, The roll changing method comprises the following steps: After the roll changing of the finishing mill is completed, the simulation production is carried out by the combined coiler, the finishing mill rolls the strip, and the coiler winds the strip.

7. A roll changing method for a roll mill of a continuous casting and rolling line according to claim 6, characterized in that, The roll changing method comprises the following steps: After the simulation production is completed, in order to heat the roll and find the appropriate level value, the fourth slab is rolled by the rolling mill, and the endless strip threading is waited.

8. A roll changing method for a roll mill of a continuous casting and rolling line according to claim 7, characterized in that, The roll changing method comprises the following steps: After the endless strip threading is completed, the endless mode production is continued.

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