A method of sealing a dummy ingot in a slab caster

Abstract

The application discloses a slab continuous casting machine sealing and guiding ingot method, and specifically comprises the following steps: 1) sealing and guiding ingot preparation; 2) ingot head positioning; 3) surface cleaning and initial sealing; 4) gap filling and sealing; 5) nail scrap paving; 6) reinforcement protection; 7) finished product protection; and 8) operation control. The application aims to provide a slab continuous casting machine sealing and guiding ingot method, which realizes fine control of sealing and guiding ingot operation by defining operation requirements and parameter standards of each process, ensures sealing effect and structural stability, ensures smooth casting and convenient guiding ingot removal, and reduces production risks.

Description

Technical Field

[0001] This invention belongs to the field of steel continuous casting production technology, and particularly relates to a method for sealing ingots in a slab continuous casting machine. Background Technology

[0002] The sealing of the slab ingot is a crucial preliminary step in slab continuous casting production. Its quality directly determines the smooth start of casting and the success of subsequent ingot removal operations, thus being vital to the continuity and stability of continuous casting production. Current ingot sealing operations lack a unified standardized process, resulting in problems such as non-standard treatment of the mold corner gaps, uneven sealing between the ingot head and the mold gap, uncontrolled thickness of auxiliary material application, and insufficient protection of areas prone to steel leakage. These issues can easily lead to production accidents such as steel leakage during casting, ingot jamming during removal, and molten steel splashing that contaminates equipment, severely impacting production efficiency and product quality.

[0003] With the steel industry's increasing demands for production stability and cost control, there is an urgent need for a standardized and refined method for sealing ingots. This method should address existing technological shortcomings by optimizing operational processes and parameters without increasing equipment investment, ensuring ingot quality, and reducing the accident rate. Therefore, developing a standardized, stable, and reliable method for sealing ingots in slab continuous casting machines has significant practical importance and application value. Summary of the Invention

[0004] In order to overcome the problems of non-standard sealing of slab continuous casting machines and the resulting production accidents in the existing technology, the purpose of this invention is to provide a method for sealing slab continuous casting machines. This method achieves refined control of the sealing operation by clarifying the operation requirements and parameter standards of each process. While ensuring the sealing effect and structural stability, it also ensures smooth casting and convenient slab removal, thereby reducing production risks.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] This invention discloses a method for sealing ingots in a slab continuous casting machine, the specific steps of which include:

[0007] 1) Preparation before sealing the ingot: Before lowering the ingot, clean the copper plate and corner gaps of the crystallizer with water, and dry them with compressed air. Check the wear condition of the copper plate. Adjust the width of the upper and lower openings and the taper of the narrow side of the crystallizer according to the requirements of the steel grade to be produced. After adjustment, use a measuring rod to calibrate the width of the upper and lower openings. The taper instrument needs to be calibrated at the shift handover. If the deviation is too large during use, it needs to be calibrated in time. Use a feeler gauge to check the corner gaps on the narrow side. The corner gaps within 500mm from the top of the crystallizer should not be greater than 0.3mm, and those below 500mm should not be greater than 0.5mm. If they are not qualified, notify the equipment personnel to handle them or replace the crystallizer. Apply iron sludge evenly to the corner gaps and dry them through the air duct.

[0008] 2) Positioning of the ingot head: Move the ingot head jog to a position 500mm away from the upper edge of the copper plate of the crystallizer. The measurement reference is the distance from the upper edge of the inner arc of the ingot head to the upper surface of the copper plate.

[0009] 3) Surface cleaning and initial sealing: Clean the surface of the ingot head with compressed air to ensure that there is no moisture, oil, dust and other debris; use asbestos cloth to fill the inner and outer arc slides and narrow sides of the crystallizer to prevent molten steel from splashing into the copper plate slide and narrow surface gaps during pouring.

[0010] 4) Gap filling and sealing: First, use a special copper rod to fill the gap between the copper plate of the crystallizer and the ingot head with asbestos rope. Adjust the ingot head to make the inner and outer arc gaps the same size. Two people fill the gaps from the middle to both sides in sequence. When the gap on the narrow side is large, fold the asbestos rope in half and twist it before use. Make sure the asbestos rope is flat and not higher than the plane of the ingot head. Then fill the gaps with paper rope according to the same operation procedure to form a double-layer sealing structure.

[0011] 5) Nail chip filling: Select nail chips that are free of water, oil, rust, and debris, and spread them in the order of "inner arc - two narrow faces - outer arc". Strictly control the thickness of the nail chips to 10-15mm, and confirm the uniformity of the nail chips in the dovetail groove by touch.

[0012] 6) Reinforcement and Protection: Insert a steel plate into each of the two inclined sides of the dovetail groove of the ingot head, ensuring that the steel plate is inserted into the bottom of the ingot head and is in close contact with the inclined side of the dovetail groove and the outer arc copper plate. Fill the space between the steel plate and the inclined side with iron sand; cover the dovetail groove with angle iron, control the spacing of the angle iron, and install iron hooks on both sides of the dovetail groove; press the upper surface of the ingot head with the copper plate with a long iron plate, and press the narrow side contact area with a long iron sheet with angle iron and an iron block. Stack iron sheets on the long iron sheet of the inner arc and press them together; sprinkle a layer of iron sand evenly inside the crystallizer.

[0013] 7) Finished product protection: Cover the top of the crystallizer with cardboard and remove it when pouring begins to prevent foreign objects from falling into the crystallizer;

[0014] 8) Operation control: The sealing ingot material must be prepared in advance to ensure that it is dry and the size is appropriate. The exhaust fan must be kept running normally during the operation. The operation must be carried out at the refining and feeding stage and monitored by the machine operator and deputy foreman throughout the process. After sealing, the foreman must confirm again.

[0015] Furthermore, the deviation between the upper and lower openings is ≤0.2mm.

[0016] Furthermore, the thickness of the nail chips is controlled to 12mm.

[0017] Furthermore, the spacing between the angle irons is controlled at 5cm.

[0018] Furthermore, the nail chips are spread to a thickness of 10mm.

[0019] Furthermore, the spacing between the angle irons is controlled at 4cm.

[0020] Furthermore, the thickness of the nail chips is 15mm.

[0021] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0022] This invention standardizes the sealing and drawing process by designing standardized procedures and controlling parameters. It solves the problems of non-standardization in key aspects such as corner treatment, gap sealing, and material filling in traditional operations, and significantly reduces the incidence of production accidents such as steel leakage and difficulty in drawing and drawing.

[0023] The structure design employs a double-layer seal of "asbestos rope + paper rope", special reinforcement with dovetail groove, and multiple compression protection to ensure the sealing performance and structural stability of the sealing ingot. At the same time, it precisely controls the thickness of the nail chip filling, taking into account both the sealing effect and the ease of unsealing the ingot.

[0024] This method does not require large-scale modifications to existing continuous casting equipment; it can be achieved simply by optimizing the workflow and operating standards. It is easy to operate, highly controllable, and easy to promote and apply, making it suitable for large-scale industrial production.

[0025] Standardized operating procedures shorten the time for sealing ingots, reduce equipment maintenance costs and production risks, and improve the continuity and stability of continuous casting production, resulting in significant economic benefits and practical value. Detailed Implementation

[0026] The present invention will be further described in detail below with reference to specific embodiments.

[0027] Example 1

[0028] A method for sealing the slab ingot in a slab continuous casting machine, comprising the following steps:

[0029] 1. Preparation before sealing the ingot: Rinse the copper plate and corner gaps of the crystallizer with water, blow dry with compressed air, and check that the copper plate has no obvious wear; adjust the width of the upper and lower openings and the taper of the narrow side of the crystallizer according to the requirements of Q235B steel grade, and the measurement rod calibration shows that the deviation of the upper and lower openings is ≤0.2mm; check the narrow side corner gap with a feeler gauge, and the upper 500mm is 0.2mm and the lower part is 0.4mm, which meets the requirements; apply iron sludge evenly to the corner gap and then blow dry with the air duct.

[0030] 2. Positioning the ingot head: Move the ingot head jog to a position 500mm from the upper edge of the copper plate of the crystallizer, and confirm that the measurement benchmark meets the standard.

[0031] 3. Surface cleaning and initial sealing: Clean the surface of the ingot head with compressed air to remove any debris; use asbestos cloth to seal the inner and outer arc tracks and narrow sides of the crystallizer.

[0032] 4. Gap filling and sealing: Special copper brazing is used to fill the asbestos rope. Adjust the dummy bar head to make the inner and outer arc gaps consistent. Two people fill it successively from the middle to both sides. The gap on the narrow side is smaller, and the asbestos rope is directly filled until it is flush; fill the paper rope according to the same process.

[0033] 5. Nail debris spreading: Select clean nail debris and spread it in the order of "inner arc - narrow side - outer arc", with the thickness controlled at 12 mm, and manually confirm that the nail debris in the dovetail groove is uniform.

[0034] 6. Reinforcement and protection: Insert steel plates into the two hypotenuses of the dovetail groove to the bottom, closely adhere to the hypotenuses and the outer arc copper plate, and fill iron sand between the steel plate and the hypotenuse; cover the angle iron completely, with the spacing controlled at 5 cm, and install iron hooks on both sides; press the long iron plate tightly at the contact between the dummy bar head and the copper plate, press tightly with long iron sheets and iron blocks with angle iron on the narrow side, and press tightly by overlapping iron sheets on the inner arc long iron sheet; sprinkle a layer of iron sand in the mold.

[0035] 7. Finished product protection: Cover the upper opening of the mold with cardboard and remove it after pouring starts.

[0036] 8. Operation control: The dummy bar sealing material is dried in advance for standby, and the exhaust fan operates normally; start the operation during the refining wire feeding stage, the shift supervisor monitors the whole process, and the foreman confirms it is qualified after sealing. After inspection, the pouring of this batch is smooth, without molten steel splashing and steel leakage phenomena, and the dummy bar removal operation is smooth, meeting the production requirements.

[0037] Example 2

[0038] A method for sealing the dummy bar of a slab continuous caster is as follows:

[0039] 1. Preparation before sealing the dummy bar: Flush and dry the copper plate of the mold and the corner joints, check that there is slight local wear on the copper plate but it does not affect use; adjust the mold parameters according to the requirements of Q355B steel grade, and the measuring rod is calibrated qualified; use a feeler gauge to detect the narrow side corner joint, which is 0.3 mm within the upper 500 mm and 0.5 mm at the lower part, meeting the requirements; smear iron mud on the corner joint and blow it dry.

[0040] 2. Dummy bar head positioning: Accurately position it at a position 500 mm from the upper edge of the copper plate.

[0041] 3. Surface cleaning and initial sealing: Clean the surface of the dummy bar head, and plug the slideway and narrow side of the mold with asbestos cloth.

[0042] 4. Gap filling and sealing: The gap on the narrow side is larger. Fold and twist the asbestos rope and then fill it to ensure that it is严实平齐 around; subsequently fill the paper rope to complete double-layer sealing.

[0043] 5. Nail debris spreading: The thickness of spreading clean nail debris is 10 mm, and manually confirm that there is no vacancy and it is uniform in the dovetail groove. 6.

[0044] 6. Reinforcement and protection: Insert steel plates and fill with iron sand, cover with angle iron (spaced 4cm apart), and install iron hooks; after pressing with multiple iron plates, sprinkle iron sand into the crystallizer.

[0045] 7. Finished product protection: Cover the top with cardboard.

[0046] 8. Operational Control: Materials were dry, equipment was functioning normally, and the refining and wire feeding stages were monitored by two people, with final confirmation from the foreman. The casting process was stable, with no production accidents, and the shunting of the ingots proceeded smoothly, meeting the requirements for continuous casting production.

[0047] Example 3

[0048] A method for sealing the slab ingot in a slab continuous casting machine, comprising the following steps:

[0049] 1. Preparation before sealing the ingot: Rinse and dry the copper plates and corner gaps of the crystallizer, ensuring the copper plates are free from wear; adjust the crystallizer parameters according to the SPHC steel grade and calibrate them to meet the standards; check that the corner gaps meet the standards, and apply iron sludge and blow it dry.

[0050] 2. Positioning of the ingot head: Position it to the standard position of 500mm.

[0051] 3. Surface cleaning and initial sealing: Clean the spindle head, seal the slide and narrow side with asbestos cloth.

[0052] 4. Gap filling and sealing: Double-layer filling with asbestos rope and paper rope to ensure a tight seal.

[0053] 5. Nail chip filling: Nail chips should be 15mm thick and evenly filled in the dovetail groove.

[0054] 6. Reinforcement and protection: Steel plate insertion, iron sand filling, angle iron laying, multiple pressing and iron sand spreading are all carried out in accordance with standard procedures.

[0055] 7. Finished product protection: Cover the top with cardboard.

[0056] 8. Work control: The entire process shall be carried out in accordance with the specifications, and monitoring shall confirm that it is qualified.

[0057] The casting and de-derived ingots for this batch were completed smoothly without any production risks and met the process requirements.

[0058] To verify the feasibility of the method of this invention, the applicant conducted a comparative experiment, selecting 20 batches of slab continuous casting production. Ten batches used the traditional sealing ingot method (control group), and ten batches used the method of this invention (experimental group). The operational quality and production indicators of the two groups were compared, and the results are as follows:

[0059] The pass rate of the sealing ingot was 82% in the control group, with 5 cases of steel leakage and 3 cases of difficulty in detaching the ingot; the pass rate of the sealing ingot in the experimental group was 98%, with no steel leakage and only 1 case of slight detachment of the ingot (which was successfully completed after adjustment), and the stability of the operation was significantly improved.

[0060] Production efficiency: The average operation time for sealing ingots in the control group was 45 minutes per furnace. Through standardized process optimization, the average operation time in the experimental group was shortened to 32 minutes per furnace, resulting in a 28.9% increase in production efficiency. 3. Equipment wear and tear: The control group suffered damage to the copper plates of the crystallizer due to splashing molten steel twice. The experimental group experienced no equipment contamination or damage, leading to reduced equipment maintenance costs.

[0061] The embodiments described above are merely preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Various modifications and improvements made by those skilled in the art to the technical solutions of the present invention without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. A method for sealing the slab ingot in a slab continuous casting machine, characterized in that: The specific steps include: 1) Preparation before sealing the ingot: Before lowering the ingot, clean the copper plate and corner gaps of the crystallizer with water, and dry them with compressed air. Check the wear condition of the copper plate. Adjust the width of the upper and lower openings and the taper of the narrow side of the crystallizer according to the requirements of the steel grade to be produced. After adjustment, use a measuring rod to calibrate the width of the upper and lower openings. The taper instrument needs to be calibrated at the shift handover. If the deviation is too large during use, it needs to be calibrated in time. Use a feeler gauge to check the corner gaps on the narrow side. The corner gaps within 500mm from the top of the crystallizer should not be greater than 0.3mm, and those below 500mm should not be greater than 0.5mm. If they are not qualified, notify the equipment personnel to handle them or replace the crystallizer. Apply iron sludge evenly to the corner gaps and dry them through the air duct. 2) Positioning of the ingot head: Move the ingot head jog to a position 500mm away from the upper edge of the copper plate of the crystallizer. The measurement reference is the distance from the upper edge of the inner arc of the ingot head to the upper surface of the copper plate. 3) Surface cleaning and initial sealing: Clean the surface of the ingot head with compressed air to ensure that there is no moisture, oil, dust and other debris; use asbestos cloth to fill the inner and outer arc slides and narrow sides of the crystallizer to prevent molten steel from splashing into the copper plate slide and narrow surface gaps during pouring. 4) Gap filling and sealing: First, use a special copper rod to fill the gap between the copper plate of the crystallizer and the ingot head with asbestos rope. Adjust the ingot head to make the inner and outer arc gaps the same size. Two people fill the gaps from the middle to both sides in sequence. When the gap on the narrow side is large, fold the asbestos rope in half and twist it before use. Make sure the asbestos rope is flat and not higher than the plane of the ingot head. Then fill the gaps with paper rope according to the same operation procedure to form a double-layer sealing structure. 5) Nail chip filling: Select nail chips that are free of water, oil, rust, and debris, and spread them in the order of "inner arc - two narrow faces - outer arc". Strictly control the thickness of the nail chips to 10-15mm, and confirm the uniformity of the nail chips in the dovetail groove by touch. 6) Reinforcement and Protection: Insert a steel plate into each of the two inclined sides of the dovetail groove of the ingot head, ensuring that the steel plate is inserted into the bottom of the ingot head and is in close contact with the inclined side of the dovetail groove and the outer arc copper plate. Fill the space between the steel plate and the inclined side with iron sand; cover the dovetail groove with angle iron, control the spacing of the angle iron, and install iron hooks on both sides of the dovetail groove; press the upper surface of the ingot head with the copper plate with a long iron plate, and press the narrow side contact area with a long iron sheet with angle iron and an iron block. Stack iron sheets on the long iron sheet of the inner arc and press them together; sprinkle a layer of iron sand evenly inside the crystallizer. 7) Finished product protection: Cover the top of the crystallizer with cardboard and remove it when pouring begins to prevent foreign objects from falling into the crystallizer; 8) Operation control: The sealing ingot material must be prepared in advance to ensure that it is dry and the size is appropriate. The exhaust fan must be kept running normally during the operation. The operation must be carried out at the refining and feeding stage and monitored by the machine operator and deputy foreman throughout the process. After sealing, the foreman must confirm again.

2. The method for sealing the slab ingot in a slab continuous casting machine according to claim 1, characterized in that: The deviation between the upper and lower openings is ≤0.2mm.

3. The method for sealing the slab ingot in a slab continuous casting machine according to claim 1, characterized in that: The thickness of the nail chips should be controlled at 12mm.

4. The method for sealing the slab ingot in a slab continuous casting machine according to claim 1, characterized in that: The spacing between angle irons should be controlled at 5cm.

5. The method for sealing the slab ingot in a slab continuous casting machine according to claim 1, characterized in that: The nail chips are spread to a thickness of 10mm.

6. The method for sealing the slab ingot in a slab continuous casting machine according to claim 5, characterized in that: The spacing between angle irons should be controlled at 4cm.

7. The method for sealing the slab ingot in a slab continuous casting machine according to claim 1, characterized in that: Nail chips are 15mm thick.