Steel ladle and manufacturing method thereof

Abstract

The invention relates to the technical field of metallurgy, in particular to a steel ladle and a manufacturing method thereof. The manufacturing method of the steel ladle comprises the following steps: mounting the seating brick, building the ladle bottom working layer, building the ladle wall working layer and the ladle opening working layer, and coating a repairing material; the indexes of the repairing material are as follows: the mass content of Al2O3 is greater than or equal to 76%, the volume density is greater than or equal to 2.75 g / cm < 3 >, and the compressive strength is greater than or equal to 30Mpa. According to the steel ladle manufacturing method, the steel ladle working layer can be effectively protected, the erosion resistance and oxidation resistance of the steel ladle working layer are improved, and the service life of the steel ladle working layer is prolonged.

Description

Technical Field

[0001] The invention relates to the technical field of metallurgy, in particular to a ladle and a manufacturing method thereof. Background Art

[0002] The ladle is a high-temperature device used for temporary storage, transportation, pouring of molten steel, and refining outside the furnace. With the development of metallurgical industry technology, the capacity of the ladle is getting larger and larger, and the residence time of molten steel in the ladle is getting longer and longer. Since the molten steel needs to undergo multiple technical processes in the ladle, its residence time in the working layer of the ladle is significantly extended, resulting in large heat loss and a rapid drop in the temperature of the molten steel. In order to ensure the smooth progress of continuous casting, temperature compensation has to be carried out by increasing the tapping temperature, raising the temperature during refining, or heating in the tundish. However, in terms of increasing the tapping temperature, this will inevitably accelerate the process of damage to the working layer of the ladle, significantly reduce the life of the ladle, seriously affect the output of steel, and will lead to worse conditions for the use of the working layer of the ladle. Summary of the invention

[0003] In order to solve the defects in the prior art, the present invention provides a ladle and a manufacturing method thereof, which can effectively protect the working layer of the ladle, improve its anti-corrosion and anti-oxidation properties, and increase the service life of the working layer of the ladle.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] In a first aspect, the present invention provides a method for making a ladle, comprising the following steps:

[0006] Install the base bricks, lay the bottom working layer, lay the wall working layer and the mouth working layer, and apply the repair materials;

[0007] The indicators of the repair material are Al2O3 mass content ≥76%, volume density ≥2.75g / cm 3 , compressive strength ≥30Mpa.

[0008] Preferably, the seat bricks are nozzle seat bricks and argon blowing seat bricks.

[0009] Preferably, the process of installing the seat bricks is specifically as follows: applying plastic fire clay on the flat surface of the seat brick metal tray, placing the seat bricks on it, rotating the seat bricks to make the fire clay in good contact with the seat bricks, and filling and compacting the gaps around the seat bricks and the permanent layer or the bottom bricks with corundum castables.

[0010] Preferably, the process of laying the bottom covering working layer is specifically as follows: first laying the bottom covering working layer, and then laying the impact layer.

[0011] Preferably, the bottom working layer of the masonry package is laid by dry method, starting from between the seat bricks, and laying the longitudinal long seams along the direction of the package. Pay attention to adjusting the selection of bricks. Bricks should be cut when laying to the corners. When the cut bricks are smaller than 1 / 2 of the mother bricks, fill them with castables for masonry.

[0012] Preferably, when laying the impact layer, gaps should be reserved around the seat bricks, which are then filled with corundum castables after laying, and a gap of about 40 mm is reserved between the permanent layer of the wall, which is secured with broken bricks and filled tightly, compacted and leveled with corundum castables.

[0013] Preferably, laying the wall working layer includes first laying the slag line working layer bricks and then laying the wall working layer bricks.

[0014] Preferably, the bottom of the brick stack of the wall working layer starts at the slag pouring surface side, and the closing door is at the water inlet side opposite to the slag pouring surface.

[0015] In a second aspect, the present invention provides a ladle produced by the above production method.

[0016] Preferably, the structure of the ladle includes a ladle bottom permanent layer, a ladle bottom impact layer, a ladle bottom working layer, seat bricks, a ladle wall permanent layer, a ladle wall working layer, a slag line permanent layer, a slag line working layer and a ladle mouth working layer.

[0017] Preferably, the seat bricks are nozzle seat bricks and argon blowing seat bricks.

[0018] The beneficial effects of the present invention are:

[0019] The ladle manufactured by the method described in the present application can effectively protect the working layer of the ladle, improve its corrosion resistance and oxidation resistance, and increase the service life of the working layer of the ladle. DETAILED DESCRIPTION

[0020] In order to enable those skilled in the art to better understand the technical solution of the invention, the present invention is further described in detail below in conjunction with specific implementation methods.

[0021] The technical standards of the materials of various parts used in the embodiments of the present invention are shown in the following tables.

[0022] Table 1. Ladle Bricks

[0023]

[0024]

[0025] Table 2. Castable materials for permanent layer of ladle (NC code 010304020004)

[0026] project unit index <![CDATA[Al2O3]]> ％ ≥60.0 Bulk density <![CDATA[g / cm 3 ]]> ≥2.60 Compressive strength MPa ≥30

[0027] Table 3. Ladle mouth material (NC code 010304029055)

[0028] project unit index <![CDATA[Al2O3]]> ％ ≥55.0 Bulk density <![CDATA[g / cm 3 ]]> ≥2.50 Compressive strength MPa ≥30

[0029] Table 4. Repair materials (NC code 010304020003)

[0030] project unit index <![CDATA[Al2O3]]> ％ ≥76.0 Bulk density <![CDATA[g / cm 3 ]]> ≥2.75 Compressive strength MPa ≥30

[0031] Table 5. Drainage sand (NC code 010310000002)

[0032] project unit index <![CDATA[SiO2]]> ％ ≥80 <![CDATA[H2O]]> ％ ＜1.0 Refractoriness ℃ ≥1750

[0033] Table 6. Nozzle seat brick (NC code 010304029057)

[0034]

[0035]

[0036] Table 7. Air brick (NC code 010304029058)

[0037] project unit Breathable brick core Breathable seat brick <![CDATA[MgO+Al2O3+Cr2O3]]> ％ ≥93 ≥90 Bulk density <![CDATA[g / cm 3 ]]> ≥3.0 ≥2.90 Normal temperature compressive strength MPa ≥90 ≥30

[0038] Table 8. Clay brick (NC code 010303020094)

[0039] project unit index <![CDATA[Al2O3]]> ％ ≥30 Bulk density <![CDATA[g / cm 3 ]]> ≥2.0

[0040] Example 1

[0041] The present embodiment provides a method for manufacturing a ladle, wherein the ladle comprises a ladle bottom permanent layer, a ladle bottom impact layer, a ladle bottom working layer, a seat brick, a ladle wall permanent layer, a ladle wall working layer, a slag line permanent layer, a slag line working layer and a ladle mouth working layer; each permanent layer is manufactured according to a conventional method in the art, and the manufacturing method of the remaining parts comprises the following steps:

[0042] S1. Installation of seat bricks: The seat bricks are nozzle seat bricks and argon blowing seat bricks. The installation steps are as follows:

[0043] (1) Check the metal tray of the brick seat to ensure that there is no cracking, deformation, or open welding;

[0044] (2) Apply a uniform layer of plastic fire clay on the metal tray of the base brick, place the nozzle base brick and argon blowing base brick on it, and rotate the base brick to make the fire clay and base brick in good contact, with a gap of ≤2mm;

[0045] (3) The gaps between the nozzle seat bricks and the argon blowing seat bricks and the permanent layer or bottom bricks are filled and compacted with corundum castables;

[0046] S2. Masonry of the bottom working layer:

[0047] (1) Check the permanent layer at the bottom of the package. If there are any uneven areas, they must be repaired. When repairing, magnesia sand is generally used to level the surface, with a thickness of about 5 mm.

[0048] (2) Lay the bottom working layer. The brick surface should be flat and without steps. The bricks of the bottom working layer should be laid by dry method. Start from the gap between the water inlet and the argon blowing bricks. Lay the long longitudinal seam along the direction of the bag (the line connecting the two ear axes). Pay attention to the selection of bricks. When laying to the corners, the bricks should be cut. When the cut bricks are smaller than 1 / 2 of the mother bricks, they can be filled with castables for masonry.

[0049] (3) When laying the impact area, pay attention to distinguishing the brick types in the non-impact area and the impact area of ​​the bottom package, and place them in the right position; reserve gaps around the sprue seat bricks and argon blowing seat bricks, and fill them with corundum castables after laying; reserve a gap of about 40 mm between the permanent layer of the package wall, fix it with broken bricks, and fill it tightly with corundum castables, tamp it, and level it; the brick gap should not be larger than 1 mm.

[0050] S3. Masonry of the wall working layer and the opening working layer:

[0051] (1) Before laying the wall working layer, the residual back seam material attached to the surface of the permanent layer of the wall should be cleaned and the permanent layer should be inspected and repaired;

[0052] (2) Laying the wall working layer: First lay the slag line working layer bricks, then lay the wall working layer bricks; the bottom of the wall working layer bricks should start at the slag pouring surface side, and the door should be closed at the slag pouring surface side of the water inlet. It is strictly forbidden to close the door at the slag pouring surface side or the air permeable brick side; the door should be closed layer by layer, and the positions of the doors of the upper and lower layers must be staggered by more than two bricks, and the brick seams of the upper and lower layers must be staggered; during the laying process, the fire mud should be ensured to be full, and it is required to knock every three or four bricks with a wooden hammer to make the bricks stand upright and close together, with tight brick seams and a brick seam of ≤1mm; when each ring of bricks is laid to the last 4 to 6 bricks, a steel tape measure should be used to measure the remaining The size of the remaining section determines the processing size of the door bricks. If two door bricks must be processed, the two door bricks cannot be used together, and a non-processed brick must be sandwiched in the middle; the door bricks should be measured according to the width of the joint and cut on a brick cutter; if the width of the joint is less than 50mm, a brick on the edge of the joint should be removed and two cut bricks should be used to close the joint; during masonry, there should be no obvious misalignment between layers; after each layer is laid, the bricks are pried tight from the outside to the inside with a putty knife, and the seam between the working layer and the permanent layer is filled with back seam material and fire clay for bricklaying.

[0053] (8) When building the working layer of the package mouth, weld a fixing steel plate (also called flange) when sealing the package mouth, and repair the damaged ones in time.

[0054] S4. Ladle coating repair material. Ladle coating / gunning material is to increase the service life of the ladle. It is combined with water and evenly applied to the working layer of the ladle after major or minor repairs. It can effectively protect the working layer of the ladle, resist erosion and oxidation, and increase the service life of the working layer of the ladle.

[0055] Example 2

[0056] The performance of the ladle produced in Example 1 was tested, and the results were as follows:

[0057] 1. The design furnace life of the corundum bricks is ≥145 furnaces.

[0058] 2. The baking process is carried out according to the baking process of magnesia carbon brick ladle (low fire 12 hours, medium fire 24 hours, high fire 24 hours), and the online ladle temperature is ≥850 degrees.

[0059] 3. A newly built ladle (160mm for the wall and 180mm for the slag line) should be put into use for about 80 minor repairs, such as replacing the slag line, bottom blowing air bricks and nozzle seat bricks; and for more than 145 major repairs, such as replacing the bottom bricks, wall bricks, slag line bricks, sealing bricks, etc.

[0060] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. A method for making a ladle, characterized in that: The following steps are involved: Install the base bricks, lay the bottom working layer, lay the wall working layer and the mouth working layer, and apply the repair materials; The indicators of the repair material are Al2O3 mass content ≥76%, volume density ≥2.75g / cm 3 , compressive strength ≥30Mpa.

2. The method according to claim 1, characterized in that: The process of installing the seat brick is specifically as follows: applying plastic fire clay on the flat surface of the metal tray of the seat brick, placing the seat brick on it, rotating the seat brick to make the fire clay in good contact with the seat brick, and filling and compacting the gap between the seat brick and the permanent layer or the bottom brick with corundum castable.

3. The method according to claim 1, characterized in that: The process of laying the bottom working layer is specifically as follows: first laying the bottom working layer, and then laying the impact layer.

4. The method according to claim 1 or 3, characterized in that: The working layer of the bottom of the masonry package is laid by dry method, starting from between the seat bricks, and the longitudinal long seam is laid along the direction of the bag. Pay attention to the selection of bricks. Bricks should be cut when laying to the corners. When the cut bricks are smaller than 1 / 2 of the mother bricks, fill them with castables for masonry.

5. The manufacturing method according to claim 3, characterized in that: When laying the impact layer, a gap should be reserved around the seat bricks. After laying, it should be filled with corundum castable. A gap of about 40mm should be reserved between the permanent layer of the wall, which should be fixed with broken bricks and filled tightly, compacted and leveled with corundum castable.

6. The method according to claim 1, characterized in that: The laying of the wall working layer comprises laying the slag line working layer bricks first and then laying the wall working layer bricks.

7. The production method according to claim 1 or 6, characterized in that: The bottom of the brick stack of the wall working layer starts at the slag pouring surface side, and the closing door is at the water inlet side opposite to the slag pouring surface.

8. A ladle manufactured by the manufacturing method according to any one of claims 1 to 7.

9. The ladle according to claim 8, characterized in that The structure of the ladle comprises a ladle bottom permanent layer, a ladle bottom impact layer, a ladle bottom working layer, a seat brick, a ladle wall permanent layer, a ladle wall working layer, a slag line permanent layer, a slag line working layer and a ladle mouth working layer.

10. The ladle according to claim 9, characterized in that The seat bricks are nozzle seat bricks and argon blowing seat bricks.

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