A quick hot repair method for a continuous casting tundish

Abstract

The application discloses a kind of quick hot repair methods of continuous casting tundish, comprising: 1) using special-shaped integral pouring member;The special-shaped integral pouring member is integrally poured using magnesium-aluminum refractory material, and is formed using rotary kiln dry;The design of the special-shaped integral pouring member is: the thickness is 85mm, and each part is uniform and consistent.Further, it is designed to be spliced in straight line, the length of first section is 75mm, the length of second section is 85mm, and the included angle with first section is 105;2) the construction steps of special-shaped integral pouring member include: first, clean the material dropping area until the permanent layer is exposed;Second, place the special-shaped integral pouring member, and fix it using a support;Finally, use castable to fill between permanent layer and special-shaped integral pouring member.The application realizes the quick hot repair of continuous casting tundish, fast turnover rate, reduces the operation time of tundish, reduces the labor intensity of tundish operation, and meets the goal of improving the efficiency of continuous casting.

Description

Technical Field

[0001] This invention relates to the field of continuous casting technology, and in particular to a rapid hot repair method for a continuous casting tundish. Background Technology

[0002] The tundish in a continuous casting machine is a crucial part of the continuous casting production process. It is a high-temperature liquid container whose safety, lifespan, and performance significantly impact production efficiency, steelmaking costs, and product quality. The tundish is constructed from a combination of high-temperature resistant materials. Different smelting processes require different tundish shapes and refractory configurations. Its lining typically consists of a permanent layer and a working layer. The permanent layer is usually cast using castable refractory, while the working layer is formed by vibratory tamping of magnesia dry refractory. The primary function of the tundish is to hold and transfer molten steel. Molten steel from the ladle is held, calmed, and kept at a suitable temperature before being distributed to the crystallizer through nozzles within the tundish, completing the process from molten steel to steel billets. The part of the tundish in contact with the high-temperature molten steel is mainly the working layer refractory material; its quality directly determines the tundish's lifespan and the quality of the molten steel. The joint between the impact zone and the casting zone of the tundish is a two-dimensional heat transfer zone with high heat flux density and strong impact force of molten steel. In actual production, large-area peeling of the working layer often occurs, posing a significant safety risk. After the tundish is removed from the production line, this area is usually repaired with a coating material. This method has significant hidden dangers, including: 1) manual coating operations are difficult to standardize and are affected by the worker's skill and sense of responsibility; 2) the coating material has significant differences in characteristics from the casting material itself. The coating material contains a large amount of moisture, and after baking, it has many air gaps and pores, significantly reducing its corrosion resistance and posing a safety hazard. To address these problems, this invention provides a rapid hot repair method and component for continuous casting tundishes. Summary of the Invention

[0003] The purpose of this invention is to provide a rapid hot repair method for continuous casting tundishes, which enables rapid hot repair of continuous casting tundishes, increases turnover rate, reduces tundish operation time, reduces labor intensity in tundish operations, and meets the goal of improving efficiency in continuous casting.

[0004] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0005] This invention provides a rapid hot repair method for a continuous casting tundish, comprising:

[0006] 1) Use irregularly shaped monolithic cast components;

[0007] The irregularly shaped integral cast-in-place component is integrally cast using magnesium-aluminum refractory material and dried and shaped using a rotary kiln.

[0008] The irregularly shaped integral cast component is designed with a thickness of 85mm and uniform thickness in all parts. Furthermore, it employs a straight-line splicing design, with the first segment being 75mm long and the second segment being 85mm long, forming an angle of 105 degrees with the first segment.

[0009] The irregularly shaped integral casting component is used to replace the dry material working lining formed by tamping at the joint position of the tundish impact zone and the casting zone.

[0010] 2) The construction steps for irregularly shaped monolithic cast-in-place components include:

[0011] First, clean the area where material has fallen off until the permanent layer is exposed; second, place the irregularly shaped monolithic cast-in-place component and fix it with a bracket; finally, fill the space between the permanent layer and the irregularly shaped monolithic cast-in-place component with castable refractory.

[0012] Furthermore, the chemical composition of the refractory material by mass percentage is: MgO ≥ 70%, Al2O3 ≥ 15%, SiO2 ≤ 3%, CaO ≤ 2%, Fe2O3 ≤ 1.5%.

[0013] Furthermore, the chemical composition of the castable by mass percentage is as follows: MgO ≥ 75%, Al2O3 ≤ 10%, SiO2 ≤ 5%, C ≤ 4%, Fe2O3 ≤ 1.5%.

[0014] Furthermore, the casting process parameters are as follows: the water content of the castable is 10.5±0.3%, that is, for every 100kg of refractory material, 10.5±0.3kg of water is added; first add 90% of the required water and stir for 2-3 minutes, then add the remaining 10% of the water and stir for 1-2 minutes before discharging for casting.

[0015] Furthermore, the mixed casting material must be used within 15 minutes; after casting, it needs to be cured for 8 hours before demolding.

[0016] Compared with the prior art, the beneficial technical effects of the present invention are as follows:

[0017] This invention meets the needs of continuous casting production. This technology can be widely and comprehensively promoted in the field of continuous casting production. It can be implemented conveniently and simply and achieves good results. Attached Figure Description

[0018] The present invention will be further described below with reference to the accompanying drawings.

[0019] Figure 1 Actual image of an irregularly shaped monolithic cast component;

[0020] Figure 2 Rendering of the effect of using an irregularly shaped monolithic cast component. Detailed Implementation

[0021] A rapid hot repair method for a continuous casting tundish, specifically including:

[0022] 1) Use irregularly shaped monolithic cast components;

[0023] The aforementioned irregularly shaped monolithic cast components are integrally cast using magnesium-aluminum refractory materials and dried and formed in a rotary kiln. The composition of the refractory material is: MgO≥70%, Al2O3≥15%, SiO2≤3%, CaO≤2%, Fe2O3≤1.5%.

[0024] The preferred design for an irregularly shaped monolithic cast component is: a thickness of 85mm, with all parts being uniformly consistent. Furthermore, a straight-line splicing design is adopted, with the first segment being 75mm long and the second segment being 85mm long, forming an angle of 105° with the first segment. See details below. Figure 1 .

[0025] The function of the irregularly shaped integral cast-in-place component is to replace the dry-mix working lining formed by tamping at the joint position of the tundish impact zone and the casting zone.

[0026] 4) The construction steps for irregularly shaped monolithic cast-in-place components include:

[0027] First, clean the area where material has fallen off until the permanent layer is exposed; second, place the irregularly shaped integral cast-in-place component and fix it with a bracket; third, fill the space between the permanent layer and the component with castable refractory.

[0028] The material requirements for the above-mentioned castable are: MgO ≥ 75%, Al2O3 ≤ 10%, SiO2 ≤ 5%, C ≤ 4%, Fe2O3 ≤ 1.5%.

[0029] The preferred process parameters for casting are as follows: the water content of the castable is 10.5±0.3%, that is, 10.5±0.3 kg of water is added for every 100 kg of refractory material; first add 90% of the required water and stir for 2-3 minutes, then add the remaining 10% of the water and stir for 1-2 minutes before discharging for casting; the mixed castable must be used within 15 minutes; after casting, it needs to be cured for 8 hours before demolding;

[0030] The present invention will be described in detail below through specific embodiments. These embodiments are intended to help understand the present invention and are not intended to limit the scope of the present invention.

[0031] Example 1: Production and Application of Heavy Rail Steel by Inner Mongolia Baogang Steel Union Co., Ltd.

[0032] Specifically, the following steps are included:

[0033] 1) Application of U76CrRe rare earth heavy rail steel in the production of No. 5 casting machine of the steelmaking plant. The billet cross-section is 280×380mm. A total of 18 heats were produced. Production process route: KR hot metal pretreatment → converter → LF / VD refining → 280×380mm large square billet casting machine. The steel composition is shown in the table below:

[0034] Table 1. Composition of heavy rail steel (%)

[0035]

[0036]

[0037] Using this design method, 18 heats were continuously poured using electromagnetic induction heating tundish, with a total pouring time of 1008 minutes, meeting the plant's usage requirements. The residual thickness of the functional refractory material protective components after production was measured to be ≥15mm.

[0038] 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 rapid hot repair method of a continuous casting tundish, characterized by, The utility model relates to a kind of refractory lining of intermediate ladle, including: 1) using special monolithic casting component; The special monolithic casting component is integrally cast using magnesium-aluminum refractory material, and is dry formed using rotary kiln; The special monolithic casting component is designed with a thickness of 85mm, and each part is uniform, using linear splicing design, the first section length is 75mm, the second section length is 85mm, and the included angle with the first section is 105 degrees; The special monolithic casting component is used to replace the joint position of the impact area and the pouring area of the intermediate ladle, and the dry material working lining is rammed and formed; 2) the construction steps of special monolithic casting component include: First, clean the material dropping area until the permanent layer is exposed;Second, place the special monolithic casting component and fix it using a support;Finally, fill the gap between the permanent layer and the special monolithic casting component with castable refractories; The chemical composition of the refractory material contains MgO≥70%, Al2O3≥15%, SiO2≤3%, CaO≤2%, and Fe2O3≤1.5% by mass; The chemical composition of the castable refractories contains MgO≥75%, Al2O3≤10%, SiO2≤5%, C≤4%, and Fe2O3≤1.5% by mass; The process parameters for casting are as follows: the water content of the castable refractories is 10.5±0.3%, i.e., 10.5±0.3 kg of water is added per 100 kg of refractory material;First, add 90% of the required water amount, stir for 2-3 minutes, then add the remaining 10% of the water amount, stir for 1-2 minutes, and then the material is ready for casting.

2. The rapid hot repair method of a continuous casting tundish according to claim 1, characterized by, The stirred castable refractories must be used within 15 minutes;After casting, it needs to be cured for 8 hours before demolding.

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