Tundish refractory and its use

Abstract

The application discloses a tundish refractory material and application thereof, wherein the chemical composition of the tundish refractory material comprises TiO2 30-40wt%, MgO 45-60wt%, SiO2 4-6wt%, CaO 1-2wt%, organic binder 0.1-0.3wt% and inevitable impurities, wherein the weight percentage is used. The tundish refractory material provided by the application is a dry material, which has good heat resistance and can avoid hydrogen increase of molten steel.

Description

Technical Field

[0001] This invention belongs to the field of refractory materials technology, specifically relating to a tundish refractory material for tundishes and its application, and particularly to a tundish refractory material for tundishes suitable for high-grade steel and its application. Background Technology

[0002] From the perspective of limiting factors in the smelting process, the lifespan of the tundish and the performance of the crystallizer in continuous casting directly affect the quality of the cast billet, the output of the continuous casting machine, and the consumption of steel materials. The tundish refractory material, in turn, directly affects the tundish lifespan. Especially for the production of high-grade steels (such as X70, X80, and N80), there are strict requirements regarding hydrogen content; otherwise, the quality of the steel will be affected. Therefore, the hydrogen content in molten steel should be minimized, and suitable tundish refractory materials can prevent hydrogen enrichment in the molten steel. Summary of the Invention

[0003] To address the problems existing in the prior art, the present invention provides a tundish refractory material, which is a dry material, and its chemical composition by weight percentage includes: TiO2 30-40wt%, MgO 45-60wt%, SiO2 4-6wt%, CaO 1-2wt%, organic binder 0.1-0.3wt%, and the remainder being unavoidable impurities.

[0004] In some embodiments, the organic binder is selected from one or more of the following: epoxy resin, polyvinyl alcohol resin, phenolic resin, and polyurethane.

[0005] In some embodiments, the bulk density of the refractory material in the intermediate ladle, after continuous heat treatment at 200°C for 3 hours, is 2.5-3.3 g / cm³. 3 The compressive strength is 22-26 MPa, and the flexural strength is 4.1-4.5 MPa.

[0006] In some embodiments, the flexural strength of the refractory material in the intermediate ladle is 11-16 MPa after continuous heat treatment at 1500°C for 3 hours.

[0007] The application of the tundish refractory material provided by this invention in the preparation of continuous casting machine tundishes and in the smelting of molten steel also falls within the scope of this invention.

[0008] In some embodiments, when used in smelting molten steel, the refractory material in the tundish increases the hydrogen content of the molten steel by no more than 0.1 ppm. Detailed Implementation

[0009] This invention aims to provide a refractory material for tundishes and its application, which can extend the service life of tundishes in continuous casting machines and prevent hydrogen enrichment in molten steel. This invention is mainly achieved through the following technical solutions.

[0010] This invention provides a dry-type intermediate ladle refractory material, the chemical composition of which, by weight percentage, comprises: TiO2 30-40wt%, MgO 45-60wt%, SiO2 4-6wt%, CaO 1-2wt%, organic binder 0.1-0.3wt%, and the remainder being unavoidable impurities.

[0011] In some embodiments, the organic binder may be selected from one or more of the following: epoxy resin, polyvinyl alcohol resin, phenolic resin, and polyurethane.

[0012] Testing revealed that the refractory tundish provided by this invention, after continuous heat treatment at 200℃ for 3 hours, has a bulk density of 2.5-3.3 g / cm³. 3 The compressive strength is 22-26 MPa, and the flexural strength is 4.1-4.5 MPa; after continuous heat treatment at 1500℃ for 3 hours, the flexural strength is 11-16 MPa.

[0013] Therefore, the service life of continuous casting tundishes manufactured using the tundish refractory material provided by this invention can be significantly extended. Furthermore, when molten steel is smelted using a continuous casting tundish made from the tundish refractory material of this invention, there are no instances of material collapse or ladle overturning, and the hydrogen increase in the molten steel does not exceed 0.1 ppm (1 ppm refers to a solute to solvent weight ratio of 10). -6 This significantly improved the quality of the molten steel.

[0014] 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.

[0015] Example 1

[0016] The chemical composition of the refractory material in the intermediate ladle is as follows: TiO2 30wt%, MgO 60wt%, SiO2 5.5wt%, CaO 2wt%, epoxy resin 0.3wt%, and the remainder being unavoidable impurities.

[0017] A layer of refractory material provided in Example 1 with a thickness of 5-15 mm is applied to the inner surface of the tundish of the continuous casting machine (i.e., the area where the existing refractory material is applied), and then dried at high temperature (200°C) to obtain a continuous casting machine tundish that can be used for smelting molten steel.

[0018] Testing revealed that the dry refractory material in the tundish provided in this embodiment, after continuous heat treatment at 200°C for 3 hours, had a bulk density of 3.0 g / cm³. 3 The compressive strength is 24 MPa, the flexural strength is 4.3 MPa; after continuous heat treatment at 1500℃ for 3 hours, the flexural strength is 13 MPa.

[0019] During the pouring process of molten steel from the tundish to the crystallizer, the molten steel in the tundish continuously flows into the crystallizer through the tundish nozzle. However, because there is also a ladle on the rotary table above the tundish that flows the molten steel into the tundish through a long nozzle, the molten steel level in the tundish does not fluctuate much. This also ensures that inclusions in the molten steel in the tundish will not accidentally enter the crystallizer. The refractory coating on the inner surface of the tundish protects the continuous casting machine tundish and extends its service life.

[0020] By drawing molten steel from the tundish and crystallizer into a sampler and analyzing the composition of the molten steel in the sampler, it is possible to determine whether the molten steel has been hydrogenated and the amount of hydrogen added. Testing showed that when using the tundish refractory material provided in this embodiment, the hydrogen addition to the molten steel was 0.04 ppm.

[0021] Example 2

[0022] The chemical composition of the refractory material in the intermediate ladle is as follows: TiO2 40wt%, MgO 53wt%, SiO2 4wt%, CaO 2wt%, phenolic resin 0.1wt%, and the remainder being unavoidable impurities.

[0023] Testing revealed that the dry refractory material in the tundish provided in this embodiment, after continuous heat treatment at 200°C for 3 hours, had a bulk density of 3.3 g / cm³. 3 The compressive strength is 26 MPa, the flexural strength is 4.5 MPa; after continuous heat treatment at 1500℃ for 3 hours, the flexural strength is 16 MPa.

[0024] Testing showed that when using the refractory material provided in this embodiment for tundish smelting, the hydrogen content in the molten steel was 0.05 ppm.

[0025] Example 3

[0026] The chemical composition of the refractory material in the intermediate ladle is as follows: TiO2 35wt%, MgO 57wt%, SiO2 6wt%, CaO 1wt%, polyvinyl alcohol resin 0.3wt%, and the remainder being unavoidable impurities.

[0027] Testing revealed that the dry refractory material in the tundish provided in this embodiment, after continuous heat treatment at 200°C for 3 hours, had a bulk density of 3.1 g / cm³. 3 The compressive strength is 22 MPa, the flexural strength is 4.1 MPa; after continuous heat treatment at 1500℃ for 3 hours, the flexural strength is 11 MPa.

[0028] Testing showed that when using the tundish refractory material provided in this embodiment, the hydrogen content in molten steel was 0.06 ppm.

[0029] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A refractory material for tundishes, which is a dry-type material, characterized in that, The chemical composition of the intermediate ladle refractory material, by weight percentage, includes: TiO2 30-40 wt%, MgO 45-60 wt%, SiO2 4-6 wt%, CaO 1-2 wt%, organic binder 0.1-0.3 wt%, and the remainder being unavoidable impurities; The organic binder is selected from one or more of the following: epoxy resin, polyvinyl alcohol resin, phenolic resin, and polyurethane; The refractory material in the intermediate ladle, after being heat-treated at 200℃ for 3 hours, has a bulk density of 2.5-3.3 g / cm³. 3 The compressive strength is 22-26 MPa, and the flexural strength is 4.1-4.5 MPa. The refractory material in the intermediate ladle has a flexural strength of 11-16 MPa after continuous heat treatment at 1500℃ for 3 hours.

2. The application of the tundish refractory material according to claim 1 in the preparation of tundishes for continuous casting machines.

3. The application of the tundish refractory material according to claim 1 in the smelting of steel.

4. The application according to claim 3, wherein when used in smelting molten steel, the hydrogen increase of the tundish refractory material in the molten steel does not exceed 0.1 ppm.