Steel ladle brick based on 3D printing technology and preparation method and application thereof

Abstract

The invention discloses a steel ladle brick based on a 3D printing technology and a preparation method and application of the steel ladle brick. The steel ladle brick is an arc-shaped brick, and the arc-shaped central angle is 120 degrees. According to the production and masonry mode of the integrated steel ladle bricks, brick joints with weak erosion resistance in the steel ladle can be reduced, scouring erosion to refractory bricks in the molten steel argon blowing stirring process is reduced to the maximum extent, and abnormal erosion caused by gaps generated by thermal expansion and cold contraction between bricks and between layers of the steel ladle bricks under the rapid cooling and rapid heating conditions is avoided.

Description

Technical Field

[0001] The present invention belongs to the technical field of ladle refractories for steelmaking, and particularly relates to a ladle brick based on 3D printing technology, a preparation method thereof, and an application thereof. Background Art

[0002] A ladle is a container used for refining molten steel, holding and transferring molten steel, and is composed of a steel shell and a refractory lining inside. The refractory lining includes a working layer, a permanent layer, and a heat insulation layer.

[0003] The service life of ladle refractories is affected by the quality of each ladle refractory brick, the metallurgical process, and the use scheduling factors. The failure of ladle refractory bricks mainly includes the following three types: First: chemical erosion by molten steel slag or molten steel; Second: erosion by the agitation of molten steel in the ladle and the instantaneous high temperature of the electrode, as well as the extremely rapid change of hot and cold; Third: mechanical damage such as cracks generated inside the refractory brick due to the internal stress caused by thermal shock; The above three failure factors act together.

[0004] The erosion of ladle refractories mainly occurs at the joints of ladle bricks. The joints are mainly filled with refractory mud. Coupled with the erosion of the ladle wall by the agitation of molten steel, the erosion at the joints gradually worsens and becomes more and more serious. Coupled with a large number of refractory bricks with small sizes in the ladle and a large number of joints, after the ladle is used for a period of time, the inner lining is severely eroded, as Figure 1 shown. Summary of the Invention

[0005] Technical problems to be solved: Aiming at the above technical problems, the present invention provides a ladle brick based on 3D printing technology, a preparation method thereof, and an application thereof, which can effectively solve the deficiency that the large number of joints of ladle refractories easily leads to ladle erosion.

[0006] Technical solution: In the first aspect, the present invention provides a ladle brick based on 3D printing technology, and the ladle brick is an arc-shaped brick with a central angle of 120°.

[0007] In the second aspect, the present invention provides a preparation method for the ladle brick described in the first aspect, including the following steps: (1) Use a three-dimensional scanner to scan the inner surface of the ladle after the permanent layer is built, collect the three-dimensional curved surface lattice of the ladle permanent layer surface, and process the lattice to remove abnormal points and repair missing points; (2) Import the three-dimensional lattice into the three-dimensional processing software 3Dsmax for modeling, and establish a 3D model of the arc-shaped refractory brick according to the thickness of the working layer brick; (3) Establish a refractory brick model with a central angle of 120° and an upper and lower width that conforms to the height of the ladle inner lining, and print the side length L打印 = (1 + ρ)L 边长 , where L 打印 is the side length set when printing the refractory brick, ρ is the shrinkage coefficient of the refractory mortar, and L 边长 is the side length of the obtained refractory brick; (4) Press the arc-shaped refractory brick in a press and then heat and sinter it in a sintering furnace to obtain an arc-shaped ladle brick.

[0008] Preferably, in step (1), the three-dimensional scanner collects the three-dimensional dot matrix data of the 360° barrel-shaped curved surface of the inner wall of the permanent layer of the ladle, and the collection time is after the permanent layer is laid.

[0009] Preferably, in step (2), the thickness of the working layer brick is 150 mm, and the required remaining thickness after erosion is greater than 9 mm.

[0010] In a third aspect, the present invention provides the application of the ladle brick described in the first aspect in ladle lining.

[0011] Preferably, the ladle brick is laid in the scanned ladle according to the positioning, and the joints are filled with high-strength refractory mud; after laying, the ladle is baked online.

[0012] Furthermore, the connection between the ladle bricks is a zigzag staggered structure, and the staggered structure is filled with high-strength refractory mud in the middle.

[0013] Furthermore, the ladle bricks are laid on the inner wall of the ladle in the order of scanning.

[0014] Beneficial effects: According to the severity of the erosion area of the ladle refractory brick, the present invention proposes an integrated refractory brick and uses the technology of 3D printing and one-piece molding to produce the ladle brick. According to the deformation of each ladle, the shape of the arc-shaped brick of the working layer of the ladle brick is designed one by one by using 3D scanning technology; taking advantage of the technology of 3D printing the arc-shaped brick, the shape of the ladle brick can be customized according to the actual situation of the inner wall of the permanent layer of the ladle. The formed brick is densified by using the method of air pressure pressing, and sintered into a refractory brick with quality indicators meeting the requirements. The finally produced large arc-shaped brick is integrally formed, so it has good erosion resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is an image of the ladle brick after being eroded; Figure 2 is a schematic structural diagram of the ladle brick of the present invention; Figure 3 is a side view of the connection between two ladle bricks of the present invention; Figure 4 is a preparation flow chart of the ladle brick of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0016] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments: Embodiment 1

[0017] As Figure 4 shown, the preparation process of ladle bricks is as follows: (1) Use a FreeScan Trak Nova 3D scanner to perform a 360° scan on the inner wall of the ladle after the permanent layer is laid. As Figure 1 shown, the scanning area is divided into a slag line area and a molten pool area. The three-dimensional curved surface lattice of the ladle permanent layer surface is collected, and the three-dimensional curved surface lattice is imported into the 3D processing software 3Dsmax to process the lattice, remove abnormal points, and supplement defective points; (2) Generate a ladle brick model with a central angle of 120° according to the thickness and number of segments of the working layer refractory bricks. The connection of the ladle bricks adopts a serrated meshing structure (as Figure 3 shown), and the corresponding positions of each ladle brick and the ladle inner lining are calibrated one by one; (3) Import the.STL file of the 3D printing model of the ladle brick into a Voxeljet binder jetting 3D printer, and set parameters according to the shrinkage coefficient ρ of magnesia-carbon refractory mud and alumina-magnesia-carbon refractory mud: L 打印 = (1 + ρ)L 边长 , determine the three-dimensional model of the 3D printed part, and load the prepared magnesia-carbon refractory mud to print the arc-shaped ladle bricks; (4) Place the arc-shaped ladle bricks printed (as Figure 2 shown) into a pressure mold for compacting, and compact them to the standard density to take out the billets; (5) Place the ladle bricks into a high-temperature kiln for sintering, adjust to the sintering temperature of the refractory mud, and the sintering temperature is 1400°C to 1600°C, and keep warm for 6 to 10 h to take out of the kiln; (6) Lay the ladle bricks, lay the ladle bricks on the inner wall of the ladle permanent layer according to the corresponding positions during scanning, and the bricks are connected by a serrated meshing structure, and the joints are filled with high-strength refractory mud; (7) Bake the ladle after laying and put it into operation.

[0018] The present invention relies on the technology of 3D scanning and 3D printing to form refractory materials, and makes large-sized integral arc-shaped ladle bricks for ladles, effectively avoiding the erosion of traditional masonry joints caused by the stirring of molten steel during the use of ladles, and avoiding abnormal erosion. At the same time, it also avoids the generation of gaps between layers of ladle bricks due to different expansion coefficients during the use of ladles when encountering rapid cooling and heating, reduces the erosion caused by abnormal use of ladles, and reduces the risks of ladle red envelopes and ladle breakage.

[0019] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A ladle brick based on 3D printing technology, characterized in that: The ladle brick is an arc-shaped brick with an arc central angle of 120°.

2. The preparation method of the ladle brick according to claim 1, characterized in that, It includes the following steps: (1) Use a 3D scanner to scan the inner surface of the ladle after the permanent layer is built, collect the 3D surface lattice points of the ladle permanent layer surface and process the lattice points, remove abnormal points, and repair missing points; (2) Import the 3D lattice points into the 3D processing software 3Dsmax for modeling, and establish a 3D model of the arc-shaped refractory brick according to the thickness of the working layer brick; (3)Establish a refractory brick model with a radian central angle of 120° and an upper and lower width that conforms to the height of the ladle lining, and print the side length L 打印 = (1 + ρ)L 边长 , where L 打印 is the side length set when printing the refractory brick, ρ is the shrinkage coefficient of the refractory mud, and L 边长 is the side length of the obtained refractory brick; (4) Press the arc-shaped refractory brick in a press and then heat and sinter it in a sintering furnace to obtain the arc-shaped ladle brick.

3. The preparation method according to claim 2, characterized in that: In step (1), the 3D scanner collects the 3D lattice point data of the 360° barrel-shaped surface of the inner wall of the ladle permanent layer, and the collection time is after the permanent layer is built.

4. The preparation method according to claim 2, characterized in that: In step (2), the thickness of the working layer brick is 150 mm, and the required remaining thickness after erosion during use is greater than 9 mm.

5. Application of the ladle brick according to claim 1 in ladle building.

6. The application according to claim 5, wherein: The ladle bricks are positioned and built in the scanned ladle, and the joints are filled with high-strength refractory mud; After the building is completed, the ladle is put on the line for baking.

7. The application according to claim 6, wherein: The connection between the ladle bricks is a sawtooth staggered structure, and high-strength refractory mud is filled in the staggered structure.

8. The application according to claim 6, characterized in that: The ladle bricks are built on the inner wall of the ladle in the order of scanning.

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