A method for end capping a strand cast by a slab caster

Abstract

The present application belongs to the technical field of steel production. It relates to a slab continuous caster top sealing and tail slab discharging method, which measures the tundish residual water height, converts the liquid level control from automatic to manual when the pulling speed decreases to 1 m / min, informs the tundish residual water 700 mm after the cumulative casting time in units of one minute when the tundish liquid level height reaches 700 mm, performs crystallizer liquid level slagging operation while adding new slag when the pulling speed decreases to 0.6 m / min, ensures that the crystallizer liquid level does not turn red, stops adding new protective slag when the tundish residual water height is 450 mm, decreases the pulling speed to 0.3 m / min and keeps it when the tundish residual water height is 350 mm, continuously measures the tundish residual water height, stops pouring when the tundish stopper is closed when the continuous caster residual water height is 210-270 mm, decreases the pulling speed to 0.2 m / min, stops pouring for 4 min, switches the pouring mode to the tail slab mode, and discharges the tail slab at an increased speed. The present application finely divides and precisely controls the discharging process, improves the product quality, improves the yield, and ensures the stable and smooth production.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of steel production and relates to a slab continuous casting machine top sealing and tail slab discharging method. BACKGROUND

[0002] The slab continuous casting machine top sealing operation is an important link in the continuous casting final pouring process. The continuous casting pouring process comprises three main links of starting pouring, stable pouring and stopping pouring and tail discharging. The starting pouring process and the stopping pouring and tail discharging process are the non-steady state pouring of the molten steel continuous casting, and these two links are most prone to production accidents and casting slab quality problems. The technical personnel in the field have always taken the starting pouring and stopping pouring (tail discharging) operation as the research focus, especially the continuous casting stopping pouring and tail discharging sealing is a basic process operation when a pouring is completed. In the continuous casting stopping pouring and tail discharging process, the continuous casting tail sealing is not good, and the phenomena of tail discharging molten steel overflow and welding dead bending section often occur, which not only affects the normal operation of the continuous casting, but also causes the increase of production cost. In order to ensure the benign sealing in the continuous casting stopping pouring and tail discharging process, many enterprises at home and abroad usually adopt the continuous casting low speed operation mode for a long time, but the degree of refinement is insufficient, the casting slab quality cannot be guaranteed, great casting slab waste is caused, and the material yield is reduced. SUMMARY

[0003] In view of this, the purpose of the application is to solve the above problems, and a slab continuous casting machine top sealing and tail slab discharging method is provided.

[0004] In order to achieve the above purpose, the application provides the following technical scheme:

[0005] A slab continuous casting machine top sealing and tail slab discharging method comprises the following steps:

[0006] S1, checking the four walking wheels of the tundish car and the running track for cleanness with a flashlight during the final furnace pouring period to ensure that there is no foreign matter;

[0007] S2, when the ladle stops pouring, immediately measuring the tundish slag thickness at the stopper hole with a burning oxygen pipe, and informing the steel pouring personnel when the slag thickness is greater than 80mm;

[0008] S3, when the ladle stops pouring, the automatic slag adding robot is returned to the original position;

[0009] S4, measuring the tundish water height, and when the pulling speed is reduced to 1m / min, the liquid level is controlled from automatic to manual after the steel pouring worker cooperates, and the automatic pouring equipment is removed; when the tundish liquid level height reaches 700mm, the master informs the main control room at the same time, and the main control starts timing at this time, and informs the steel pouring the cumulative pouring time after the tundish water is 700mm in one minute unit;

[0010] S5. When the pulling speed drops to 0.6m / min, perform slag removal operation on the crystallizer liquid surface and add new slag at the same time to ensure that the crystallizer liquid surface does not turn red; stop adding new protective slag when the residual water height in the tundish is 450mm.

[0011] S6. When the water level in the tundish is 350mm, reduce the casting speed to 0.3m / min and maintain it, continuously measuring the water level in the tundish. When the water level in the continuous casting machine is 210-270mm, close the stopper rod in the tundish and stop casting, reducing the casting speed to 0.2m / min. After the tundish stops casting for 4 minutes, switch the casting mode to the tail billet mode and increase the speed to exit the tail billet.

[0012] Furthermore, the method for measuring the thickness of the slag in step S2 is as follows: insert the oxygen tube into the slag at the same horizontal position as the bottom of the stopper rod, rotate it more than 2 times, and the total residence time is 4-7 seconds.

[0013] Furthermore, after the stopper rod is closed, the tail billet exiting the crystallizer and with a deviation of ≤100mm from the lower opening of the crystallizer switches to tail billet mode.

[0014] The beneficial effects of this invention are as follows:

[0015] The method in this invention achieves refined and precise control of the capping and unloading of the billet, improves product quality, increases yield, and ensures stable and smooth production.

[0016] Other advantages, objectives, and features of the invention will be set forth in part in the description which follows, and in part will be apparent to those skilled in the art from the following examination, or may be learned from practice of the invention. The objectives and other advantages of the invention can be realized and obtained through the following description. Attached Figure Description

[0017] To make the objectives, technical solutions, and advantages of the present invention clearer, the preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein:

[0018] Figure 1 This is a schematic diagram of the drawing speed control for the tail blank in this invention. Detailed Implementation

[0019] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0020] The drawings are only used for exemplary illustration, and the representation is only a schematic diagram, not a physical diagram, and cannot be understood as a limitation on the present application; in order to better illustrate the embodiments of the present application, some components in the drawings may be omitted, enlarged or reduced, and do not represent the size of the actual product; it is understandable to those skilled in the art that some well-known structures and their descriptions in the drawings may be omitted.

[0021] The same or similar reference numerals in the drawings of the embodiments of the present application correspond to the same or similar components; in the description of the present application, it should be understood that if the orientations or positional relationships indicated by the terms "upper", "lower", "left", "right", "front", "back" and the like are based on the orientations or positional relationships shown in the drawings, they are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the terms describing the positional relationship in the drawings are only used for exemplary illustration, and cannot be understood as a limitation on the present application, and for those skilled in the art, the specific meanings of the above terms can be understood according to the specific circumstances.

[0022] A slab continuous casting machine top sealing and tail slab discharging method, after the stopper is closed, the top sealing is performed according to the pulling speed control, and the tail slab discharging mode is switched when the tail slab discharging distance from the crystallizer lower opening is less than or equal to 100 mm. Figure 1 The top sealing includes the following steps:

[0023] S1, the machine length checks the four walking wheels of the tundish car and the running track with a flashlight during the last furnace pouring to ensure that there is no foreign matter.

[0024] S2, when the tundish stops pouring, the machine length immediately measures the tundish slag thickness at the stopper hole with a burning oxygen tube, if the slag thickness is greater than 80 mm, the steel pouring personnel is informed. The tundish slag thickness measurement method is that the oxygen tube is inserted into the tundish at the same horizontal line position at the bottom of the stopper, and is rotated for more than 2 circles, and the total residence time is 4-7 seconds.

[0025] S3, when the tundish stops pouring, the "return to original position" button on the robot hand control box is pressed to return the automatic slag adding robot to the original position.

[0026] S4, the remaining water height of the tundish is measured. When the pulling speed is reduced to 1 m / min (300 cross section is reduced to 0.7 m / min), the liquid level control is switched from automatic to manual after the steel pouring worker cooperates, and the automatic pouring equipment (pouring probe, electric oil cylinder, etc.) is removed. When the tundish liquid level height reaches 700 mm, the machine length simultaneously reports this information to the main control room, and the main control starts timing at this time, and the cumulative casting time after the tundish remaining water reaches 700 mm is reported to the steel pouring in one minute.

[0027] S5, when the withdrawal rate is reduced to 0.6 m / min (300 section is reduced to 0.5 m / min), the crystallizer liquid surface is slagged. At the same time, new slag is added to ensure that the crystallizer liquid surface does not turn red. Stop adding new protective slag when the tundish water height is 450 mm.

[0028] S6, when the tundish water height is 350 mm, the withdrawal rate is reduced to 0.3 m / min and kept, and the tundish water height is continuously measured. When the tundish water height of 1# and 2# continuous casting machines is 210-270 mm (generally 210-230 mm for high-quality steel and 250-270 mm for special high-quality steel), the tundish is stopped pouring and the withdrawal rate is reduced to 0.2 m / min. The tundish is stopped pouring for 4 min, the pouring mode is switched to tail blank mode on the operation box, and the speed is increased to output the tail blank.

[0029] Finally, it should be pointed out that the above examples are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced by equivalents without departing from the purpose and scope of the technical solutions, which should be covered in the scope of the claims of the present application.

Claims

1. A method of end capping a strand in a slab caster, characterised by, Comprising the following steps: S1. During the last ladle pouring, check the four walking wheels and the running track of the tundish car with a flashlight, and ensure that they are clean and intact; S2. When the ladle stops pouring, immediately measure the slag thickness in the tundish with a burning oxygen pipe at the hole of the stopper, and inform the steel pouring personnel when the slag thickness is greater than 80 mm; S3. When the ladle stops pouring, the automatic slag adding robot is returned to the original position; S4. Measure the remaining water height in the tundish, and when the withdrawal speed decreases to 1 m / min, the steel pouring worker cooperates to switch the liquid level control from automatic to manual, and then remove the automatic pouring equipment; when the liquid level in the tundish reaches 700 mm, the machine operator reports the information to the main control room at the same time, and the main control starts timing at this time, and reports the cumulative casting time after the tundish remaining water height is 700 mm to the steel pouring personnel in units of one minute; S5. When the withdrawal speed decreases to 0.6 m / min, the crystallizer liquid level is slagged, and new slag is added at the same time to ensure that the crystallizer liquid level does not turn red; when the remaining water height in the tundish is 450 mm, stop adding new protective slag; S6. When the remaining water height in the tundish is 350 mm, the withdrawal speed decreases to 0.3 m / min and remains, and the remaining water height in the tundish is continuously measured; when the remaining water height in the continuous casting machine is 210-270 mm, the tundish stops pouring with the stopper closed, and the withdrawal speed decreases to 0.2 m / min; the tundish stops pouring for 4 min, and the pouring mode is switched to the tail butt mode, and the speed is increased to output the tail butt.

2. The slab caster decked out tail method of claim 1, wherein: The method for measuring the slag thickness in the tundish in step S2 is: insert the oxygen pipe into the tundish at the same horizontal line position at the bottom of the stopper, rotate more than 2 circles, and the total stay time is 4-7 seconds.

3. The slab caster decked out tail method of claim 1, wherein: After the stopper is closed, the tail butt is out of the crystallizer and the distance from the lower opening of the crystallizer is less than or equal to 100 mm, and the tail butt mode is switched.

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