KR20000040948A - Apparatus and method of brushing surface of casting roll in twin roll type thin strip casting machine - Google Patents

Abstract

PURPOSE: A method of brushing the surface of a casting roll is provided to enhance the quality of cast pieces by controlling the compressing force and speed of main and auxiliary brush rolls. CONSTITUTION: An apparatus comprises a main brush roll(61) for brushing a center portion of a casting roll(40); a sub brush roll(62) for brushing both edges of the casting roll; a drive motor(90) for driving the main brush roll and sub brush roll; a sensor(100) for measuring widthwise temperature and brightness of a main piece; hydraulic system(80) for supplying the main and sub brush roll with compressive for brushing the surface of a casting roll(40), the length of each main/auxiliary brush roll(61,62) is decided depending on steel and casting condition. A sensor(100) measures widthwise temperature and brightness of cast pieces from the casting roll. A controller(110) obtains rotational speed and compressive force of the brush rolls with the data of the sensor. Then, the controller operates an electromotor(90) and a hydraulic system(80) to drive the main and auxiliary brush rolls with the rotational speed and compressive force. The two units are continuously operated until the widthwise temperature and brightness of cast pieces is equalized.

Description

Casting roll surface brushing apparatus and double roll type sheet casting apparatus using cast roll surface brushing method

The present invention relates to an apparatus for brushing a casting roll surface in a twin roll sheet casting apparatus for producing a thin sheet (hot coil) directly from molten steel without making slabs, and a method for brushing the casting roll surface using the same. In more detail, the present invention relates to an apparatus for brushing a casting roll surface with a plurality of brush rolls separated therefrom and a method for brushing a casting roll surface using the same.

In general, the sheet casting method receives the molten molten steel in the ladle 10, as shown in Figure 1, flows into the tundish 20 along the nozzle, the molten steel introduced into the tundish is a casting roll 40 Between the edge dam 50 provided at both ends of the, that is, between the pair roll 40 is supplied through the nozzle 30, the thin plate 70 is manufactured and wound up in the gusset facility through the cooling process.

By the above thin plate casting method, a thin plate having a thickness of 10 mm or less is manufactured.

An important technique in the twin roll sheet metal casting process for directly manufacturing a thin plate 70 having a thickness of 10 mm or less from molten steel as described above is the injection nozzle 30 between the internal water-cooled twin rolls 40 rotating in the opposite direction at a high speed. By supplying molten steel to produce a thin plate 70 of a desired thickness.

In particular, in the twin-roll thin plate casting process, where the solidification speed is relatively higher than that of the existing continuous casting, in the presence of oxidation scale or foreign substances on the surface of the roll 40, the solidification performance during casting greatly affects the quality of the casting. .

In order to solve the above problems, in the conventional twin roll casting method, as shown in FIGS. 1 and 2, an oxidation scale that adheres to the roll surface during casting by placing the brush roll 60 at an appropriate position on the surface of the roll 40 This material is being removed.

As described above, Japanese Patent Application Laid-Open Nos. 5-177311 and 9-174203 can be cited as a technique for removing an oxided scale or foreign matter that adheres to the roll surface during casting.

In Japanese Patent Laid-Open No. 5-177311, the brush roll is controlled by the starting current of the electric motor to adjust the pressing force, thereby maintaining a constant pressing force according to the casting time, thereby purifying a uniform roll surface. The arc controls the rotational speed and speed of the brush roll by considering that the degree of removal of foreign matter on the surface of the casting roll varies depending on the speed difference and the direction of the rotation of the brush roll.

However, even if the technique described in the above Japanese Patent Laid-Open is used, when the roll expands as the casting proceeds, the effect of the brush roll also varies in the roll width direction depending on the degree of expansion, and in particular, the roll surface of the edge portion is more There is a problem that coagulation is delayed due to poor cleaning.

As described above, when local coagulation delay occurs in the cast iron edge, the temperature of the cast steel of the edge portion is high and bright, and in severe cases, the swelling or tearing occurs, and the winding edge of the cast steel is severely twisted. It has a fatal effect on quality control.

The present inventors have made a study to solve the above-mentioned problems of the prior art, based on the results of the present invention, the present invention is to measure the brightness and temperature of the cast steel for the entire width of the cast steel casting By controlling the rotational speed and the pressing force of the brush roll separated into multiple parts in the width direction, the oxidized scale remaining state of the roll surface is uniformly controlled by position so that the brightness and temperature of the cast can be maintained uniformly over the entire width. Therefore, in the twin roll type sheet casting apparatus that can secure the full width uniform solidification of the cast slab to provide a brushing device of the surface of the casting roll and the brushing method of the surface of the casting roll using the same, an object thereof.

Figure 1 is a schematic diagram schematically showing a general twin-roll sheet manufacturing apparatus

2 is a partial side view of FIG. 1

Figure 3 is a schematic diagram showing the relationship between the casting roll and the brush roll according to the casting time and the full width cooling capacity (or rolling force) according to the casting time in the conventional thin plate manufacturing

(a) shows when the roll crown before casting is negative,

(b) shows the case where there is no roll crown,

(c) shows the case where the roll crown is positive during casting.

4 is a perspective view showing that the main brush roll and the sub brush roll are provided according to the present invention.

5 is a configuration diagram showing an example of a casting roll brushing device in a twin-roll thin plate casting apparatus according to the present invention;

6 is a graph showing an example of a change in slab temperature according to the slab width;

Explanation of symbols on the main parts of the drawings

40 ... Casting rolls (twin rolls) 60 ... Brush rolls 61 ... Main brushes 62 ... Parts brush rolls 70 ... Casting 80 ... Hydraulic equipment 90 ... Electric motors 100 ... Temperature and brightness sensor 110 ... controller

The present invention is a twin-roll type sheet casting apparatus configured to produce a thin plate by supplying molten steel between two casting rolls (twin roll) rotating in the opposite direction,

A main brush roll configured to wipe the center of the casting roll and a secondary brush roll configured to wipe both edge portions of the casting roll; An electric motor for driving the primary and secondary brush rolls; Cast temperature and brightness sensor for measuring the width and temperature of the cast in the width direction; A hydraulic device for providing a pressing force to the brush rolls; And it relates to a cast roll surface brushing apparatus in a twin-roll thin sheet casting apparatus comprising a control device for controlling the electric motor and the hydraulic device.

The present invention also relates to a method of brushing the surface of a casting roll by using a brushing apparatus of a casting roll in a twin roll thin sheet casting apparatus.

Hereinafter, the present invention will be described in detail with reference to the drawings.

In the twin-roll type sheet casting apparatus, the relationship between the brush roll and the casting roll according to the degree of expansion of the casting roll, and the degree of cooling ability (or reduction force) accordingly is shown schematically in FIG. 3.

As the casting progresses, the casting roll 40 expands until it reaches a steady state. In FIG. 3 (a), the casting roll 40 expands until the steady state is maintained. As before, the roll 40 before casting is processed concave.

That is, when the roll 40 is processed to expand the crown to be negative, it is almost flat.

However, it is very difficult to control the flatness, and since the degree of expansion of the roll 40 varies depending on the casting conditions, it is important to optimize the crown machining of the roll 40.

Since the heat load received by the roll 40 varies according to the temperature of the steel grade or molten steel to be cast, the thickness of the cast steel 70 to be cast, and the pressing force, the expansion degree of the roll 40 is changed. That is, when the roll 40 is concave, the pressing force of the brush roll 60 is stronger at both ends of the roll 40 than at the center, and the oxidation scale or the foreign matter is relatively small on the surface of the roll 40. ) Improves cohesion ability by improving the adhesion between the steel and molten steel.

In addition, in the case where the roll 40 expands and becomes convex as shown in FIG. 3 (b), on the contrary, the center of the roll 40 improves the adhesive force between the surface of the roll 40 and the molten steel to improve the solidification performance.

Therefore, as shown in the right side of FIG. 3, since the difference in the coagulation performance may occur with respect to the full width of the roll 40 according to the degree of expansion of the roll 40, in the present invention, the brush rolls for each position of the roll 40 ( 60) is to separate and install to make the coagulation performance uniform for the entire width of the cast steel.

That is, in the twin roll type sheet casting apparatus in accordance with the present invention, the brushing apparatus 200 on the surface of the casting roll has a main brush roll configured to wipe the center of the casting roll 40, as shown in FIGS. 4 and 5. 61 and secondary brush roll 62 configured to wipe both edges of casting roll 40; An electric motor (90) for driving the main and sub brush rolls (61, 62);

Cast temperature and brightness sensor 100 for measuring the temperature and brightness in the width direction of the cast steel; A hydraulic device (80) for providing a pressing force to the main and sub brush rolls (61) and (62); And a control device 110 configured to control the electric motor 90 and the hydraulic device 80.

The main brush roll 61 and the sub brush roll 62 are mounted to the bottom or side of each casting roll 40 to wipe the center and both edge portions of the casting roll 40, respectively.

That is, in the present invention, the brush roll is provided in a plurality of separation so as to control both the edge portion and the center portion in the width direction of the casting roll, respectively.

The diameter of the main brush roll 61 and the secondary brush roll 62 is preferably about 200 to 400 mm, and the length of the main brush roll 61 and about 0.4 to 0.8 times the width of the roll 40 in the case of the main brush roll 61, In the case of the sub brush roll 62, it is preferable to set it as 1/3 or less of the width of the casting roll 40. FIG.

The brush of the main brush roll 61 and the sub brush roll 62 is preferably made of steel wire, the length is preferably 50 to 100mm, the diameter is 0.1 to 1mm.

It is preferable that the length ratio of the said main brush roll 61 and the sub brush roll 62 is determined based on the width direction temperature distribution of a slab.

For example, as shown in FIG. 6, the widthwise temperature distribution of the slab is measured to obtain an average value Tab, and the sub-brush is formed so as to have a length corresponding to the distance from the portion showing the temperature higher than the average value to the edge. The roll 62 is provided.

On the other hand, the brush rolls 61 and 62 are rotated by the electric motor 90 and pressed by the hydraulic device 80 with a suitable force on the surface of the casting roll 40.

The slab temperature and brightness sensor 100 is provided at a position capable of properly measuring the width and temperature of the slab 70 in the width direction.

In the present invention, the main brush roll 61 is rotated while maintaining a predetermined pressing force or speed to clean the surface of the center of the casting roll 40, the secondary brush roll 62 of both edges and the temperature of the slab 70 By adjusting the hydraulic apparatus 80 and the electric motor 90 according to the brightness, the compression force and the rotational speed are controlled to maintain a uniform temperature and brightness at the full width of the cast steel (70).

Of course, if necessary, the rotational speed and the pressing force of the main brush roll 61 can also be controlled.

The control of the rotational speed of the secondary brush roll by the electric motor 90 and the pressing force of the secondary brush roll by the hydraulic device 80 is based on the slab temperature and brightness measured by the slab temperature and brightness sensor 100. It is preferable that the control device 110 is made by controlling the electric motor 90 and the hydraulic device 80.

The rotational speed and the pressing force of the main brush roll 61 are also controlled in the above manner.

Hereinafter, the method of brushing the casting roll surface using the brush apparatus of the casting roll surface in the twin roll type thin sheet casting apparatus of this invention mentioned above is demonstrated.

In order to brush the casting roll surface according to the present invention, the lengths of the main brush roll 61 and the sub brush roll 62 are determined according to the steel grade, casting conditions, and the like so that the casting roll 40 may be cleaned.

The width direction temperature and brightness of the cast slab cast between the casting rolls are measured by the slab temperature and brightness sensor 100 and sent to the control device 110.

The controller 110 calculates the rotational speed and the pressing force of the main brush roll 61 and the sub brush roll 62 using the width direction temperature and the brightness of the cast steel input as described above. The electric motor 90 and the hydraulic device 80 are controlled to operate the main brush roll 61 and the secondary broth roll 62 by the pressing force.

Continuously controlling the electric motor 90 and the hydraulic device 80 by the control device 110 until the width direction temperature and brightness of the slab measured by the slab temperature and brightness sensor 100 are uniform. do.

The rotational speeds of the main brush roll 61 and the sub brush roll 62 vary depending on casting conditions, but are preferably selected to be about 1 to 3 times the casting roll speed.

As described above, in the present invention, the clean state of the roll 40 and the brush rolls 61 and 62 is predicted by measuring the full width temperature and brightness of the slab 70 by controlling the separated brush rolls 61 and 62. The pressing force and the rotational speed of the brush rolls 61 and 62 are controlled, which will be described below.

That is, when the casting 70 is a high temperature state when measuring the temperature and brightness of the cast steel 70, the temperature and brightness appears different depending on the degree of solidification, when the localized low coagulation ability is high, the brush roll 61 By increasing the pressing force and speed of the 62, the cooling ability of the roll 40 is improved, thereby uniformly controlling the temperature and brightness of the cast steel 70. In this way, the uniformity of the entire width of the cast steel 70 is achieved. The quality of the cast can be improved by maintaining the degree of solidification.

As described above, the invention controls the pressing force or speed of the multiplely separated main brush roll and secondary brush roll when the temperature and brightness of the cast steel is measured over the full width of the cast steel during casting to show uneven cooling ability. By maintaining uniform solidification ability over the width of cast steel, it eliminates local coagulation unevenness and prevents bulging or cracking, thereby improving cast quality.

Claims (6)

In the twin roll sheet casting apparatus configured to produce molten steel between two casting rolls (twin rolls) 40 rotating in opposite directions, A main brush roll 61 configured to wipe the center of the casting roll 40 and a sub brush roll 62 configured to wipe both edge portions of the casting roll 40; An electric motor (90) for driving the main and sub brush rolls (61, 62); Cast temperature and brightness sensor 100 for measuring the temperature and brightness in the width direction of the cast steel; A hydraulic device (80) for providing a pressing force to the main and sub brush rolls (61) and (62); And Casting roll surface brushing apparatus in a twin-roll thin plate casting apparatus comprising a control device 110 configured to control the electric motor 90 and the hydraulic device 80 The length of the main brush roll 61 is 0.4 to 0.8 times the width of the casting roll 40, and the length of the sub-brush roll 62 is less than one third of the width of the casting roll (40). Casting roll surface brushing apparatus in a twin roll sheet metal casting apparatus, characterized in that The diameter of the main brush roll 61 and the sub brush roll 62 is 200 to 400 mm, and the brush of the main brush roll 61 and the sub brush roll 62 is used. Cast roll surface brushing apparatus in a twin roll sheet metal casting apparatus, characterized in that the steel wire, the length is 50 ~ 100mm, the diameter is 0.1 ~ 1mm The method of brushing a casting roll using the casting roll surface brushing apparatus in the twin-roll type sheet casting apparatus of claim 1, Determining the lengths of the main brush roll 61 and the sub brush roll 62 according to the steel type and the casting conditions, etc., so that the casting rolls 40 may be cleaned; Measuring the width direction temperature and brightness of the cast pieces exiting between the casting rolls by the cast temperature and brightness sensor 100 and sending them to the controller 110; The rotation speed and the pressing force of each of the main brush roll 61 and the secondary broth roll 62 are calculated using the width direction temperature and brightness of the cast steel measured in the controller 110 as described above. And controlling the electric motor 90 and the hydraulic apparatus 80 so that the main brush roll 61 and the sub brush roll 62 are operated by the pressing force. Continuously controlling the electric motor 90 and the hydraulic device 80 by the control device 110 until the width direction temperature and brightness of the slab measured by the slab temperature and brightness sensor 100 are uniform. Casting roll surface brushing method in a twin roll sheet casting apparatus comprising a step of The length of the main brush roll 61 is 0.4 to 0.8 times the width of the casting roll 40, and the length of the sub-brush roll 62 is less than one third of the width of the casting roll 40. ego; The diameter of the main brush roll 61 and the sub brush roll 62 is 200 to 400 mm; And the brush of the main brush roll 61 and the secondary brush roll 62 is a steel wire, the length is 50 ~ 100mm, the diameter is 0.1 ~ 1mm in the twin roll type sheet casting apparatus characterized in that the casting roll surface brush Way 6. The casting roll surface according to claim 4 or 5, wherein the rotation speed of the main brush roll 61 and the sub brush roll 62 is 1 to 3 times the casting roll speed. How to brush