Continuous casting tundish continuous casting furnace number increasing method and continuous casting system

Abstract

The invention relates to the technical field of continuous casting production, in particular to a continuous casting tundish continuous casting furnace number increasing method and a continuous casting system.The method comprises the steps that the thickness of a working layer of a tundish stopper rod area is set to be 80 mm, the thickness of a working layer of an impact area is set to be 100 mm, the thickness of a retaining wall is set to be 110 mm, a composite ceramic stopper rod with the surface of a rod head coated with a ZrO2-C coating is adopted, casting powder is used, and the continuous casting furnace number is increased; the slag line comprises, by mass, 5.69% of F <->, 32.83% of SiO2 and 38.17% of CaO, and the position of the slag line is adjusted by 5 mm every 15 min through an automatic control system. Through multi-dimensional collaborative optimization of the thickness of the tundish refractory material, improvement of the material of the stopper rod, adjustment of the components of the casting powder and dynamic control of the position of the slag line, the number of continuous casting furnaces is remarkably increased, and the industrial problems of tundish refractory material erosion, unstable flow control and short service life of the water gap are solved.

Description

Technical Field

[0001] The present invention relates to the technical field of continuous casting production, in particular to a method for increasing the number of continuous casting furnaces in a continuous casting tundish and a continuous casting system. Background Art

[0002] In the continuous casting process, the number of continuous casting furnaces in a tundish is a key indicator of continuous casting efficiency, directly impacting production costs and metal yield. Traditionally, issues such as severe tundish refractory erosion, unstable stopper flow control, strong mold slag corrosion on the nozzle, and insufficient slag line switching frequency have limited the ability to increase the number of continuous casting furnaces. Therefore, a systematic solution is urgently needed. Based on this, the present invention proposes a method and continuous casting system for increasing the number of continuous casting furnaces in a tundish. Summary of the Invention

[0003] In response to the above-mentioned technical problems, the present invention overcomes the shortcomings of the prior art and provides a method for increasing the number of continuous casting furnaces in a continuous casting tundish and a continuous casting system. By collaboratively optimizing the thickness of the refractory material in the tundish, improving the material of the stopper rod, adjusting the composition of the protective slag and dynamically controlling the position of the slag line in multiple dimensions, the number of continuous casting furnaces is significantly increased, solving the industry problems of erosion of the refractory material in the tundish, unstable flow control and short nozzle life.

[0004] In a first aspect, the present invention provides a method for increasing the number of continuous casting furnaces in a continuous casting tundish, comprising the following steps:

[0005] The working layer thickness of the tundish plug area is set to 80mm, the working layer thickness of the impact area is set to 100mm, and the retaining wall thickness is set to 110mm;

[0006] A composite ceramic plug with a ZrO2-C coating on the rod head surface is used;

[0007] The mold slag used has the following mass fraction compositions: 5.69% F-, 32.83% SiO2, 38.17% CaO;

[0008] Through the automatic control system, the slag line position is adjusted by 5mm every 15 minutes.

[0009] Furthermore, the chemical composition of the protective slag also includes: 6.52% Al2O3 and 10.72% Na2O.

[0010] In a second aspect, the present invention further provides a continuous casting system for implementing the method for increasing the number of continuous casting furnaces of a continuous casting tundish as described in any one of the first aspects, comprising a tundish, a stopper rod, a mold slag feeding device, and a slag line automatic control module, wherein the working layer thickness of the tundish stopper rod area is 80 mm, the working layer thickness of the impact area is 100 mm, and the retaining wall thickness is 110 mm;

[0011] The stopper rod tip is coated with a ZrO2-C coating;

[0012] The protective slag feeding device is equipped with the protective slag for feeding;

[0013] The slag line automatic control module operates in a cycle of adjusting 5mm every 15 minutes.

[0014] Furthermore, the stopper rod is made of composite ceramic material.

[0015] The beneficial effects of the present invention are:

[0016] (1) The present invention significantly increases the number of continuous casting furnaces by optimizing the thickness of the tundish refractory material, improving the material of the stopper rod, adjusting the composition of the protective slag, and dynamically controlling the position of the slag line in multiple dimensions, thereby solving the industry problems of tundish refractory erosion, unstable flow control, and short nozzle life.

[0017] (2) The present invention designs a working layer of 80 mm in the stopper area, a working layer of 100 mm in the impact area, and a retaining wall of 110 mm, thereby enhancing the corrosion resistance of the tundish of the continuous casting system; the ZrO2-C coated stopper improves the erosion resistance and chemical stability; the protective slag contains 5.69% F-, 32.83% SiO2, and 38.17% CaO, which reduces the erosion of the water nozzle; the slag line is adjusted by 5 mm every 15 minutes, reducing the accumulation of local corrosion. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of a continuous casting system in a specific embodiment of the present invention;

[0019] Figure 2 This is a schematic structural diagram of a stopper rod in a specific embodiment of the present invention;

[0020] Figure 3 This is a flow chart of automatic control of slag line in a specific embodiment of the present invention;

[0021] In the figure: 1. Working layer of the impact zone; 2. Molten steel; 3. First slag retaining wall; 4. Second slag retaining wall; 5. Water inlet; 6. Slag retaining dam; 7. Seat brick; 8. Impact plate; 9. Working layer of the stopper zone. DETAILED DESCRIPTION

[0022] The thickness of the existing working layer in the tundish plug rod area is 60mm, the working layer in the impact area is 60mm, and the retaining wall is 80mm, resulting in a short refractory life; the fluorine content (F-) in the protective slag is as high as 9.05%, exacerbating nozzle erosion; the slag line change interval is 20 minutes / time, which cannot effectively alleviate local erosion.

[0023] The present invention provides a continuous casting system for increasing the number of continuous casting furnaces in a continuous casting tundish, which significantly increases the number of continuous casting furnaces through the following innovative technologies:

[0024] (1) Optimization of refractory structure of tundish

[0025] like Figure 1 As shown, the continuous casting system includes an impact zone working layer 1, molten steel 2, a first slag retaining wall 3, a second slag retaining wall 4, an upper water inlet 5, a slag retaining dam 6, a seat brick 7, an impact plate 8 and a stopper zone working layer 9. The thickness of the stopper zone working layer 9 is increased from 60 mm to 80 mm, the impact zone 1 is increased from 60 mm to 100 mm, and the retaining wall thickness (first slag retaining wall 3, second slag retaining wall 4) is increased from 80 mm to 110 mm to enhance the erosion resistance.

[0026] (2) Improvement of stopper rod material and structure

[0027] like Figure 2 As shown, the plug rod is made of composite ceramic material, and the dark black surface of the rod head is coated with ZrO2-C coating to improve erosion resistance and chemical stability.

[0028] (3) Optimization of protective slag composition

[0029] As shown in Table 1, the mass fraction of F- in the mold slag decreased from 9.05% to 5.69%, SiO2 increased from 30.26% to 32.83%, and CaO increased from 31.79% to 38.17%, reducing the erosion of the ZrO2-C nozzle.

[0030] Table 1 Comparison of mold slag components

[0031] Element Before improvement (%) After improvement (%) <![CDATA[SiO2]]> 30.26 32.83 <![CDATA[Al2O3]]> 5.66 6.52 CaO 31.79 38.17 <![CDATA[Na2O]]> 8.51 10.72 <![CDATA[F - ]]> 9.05 5.69

[0032] The remaining components of the improved protective slag include but are not limited to MgO, FeO, K2O, C and TiO2. In this embodiment, the remaining component of the protective slag accounts for 6.07%, including MgO: 4.0%, FeO: 0.3%, K2O: 0.7%, and others (including impurities such as C, TiO2): 1.07%.

[0033] (4) Dynamic transformation system of slag line

[0034] like Figure 3 As shown in the figure, by adopting the automatic control system, the slag line change frequency is increased from 5mm adjustment every 20 minutes to 5mm adjustment every 15 minutes, reducing local erosion accumulation.

[0035] After the implementation of the present invention, by optimizing the refractory material of the tundish, the material of the stopper rod, the composition of the protective slag and the slag line control, the maximum number of continuous casting furnaces for a single tundish of the 1# and 2# continuous casting machines was increased from 16 to 18, and the number of furnaces for the 0# and 3# continuous casting machines was increased from 18 to 20; the service life of the tundish was extended to 750-800 minutes, saving 6.12 million yuan in annual costs for the tundish and its accessories, and reducing unplanned quality losses by 400,000 yuan. The technology is adaptable to multiple machine models and steel grades, meets the needs of green production, and has significant comprehensive economic benefits.

[0036] In addition to the above embodiments, the present invention may also have other implementations. Any technical solution formed by equivalent replacement or equivalent transformation falls within the scope of protection required by the present invention.

Claims

1. A method for increasing the number of continuous casting furnaces in a continuous casting tundish, characterized in that: The following steps are involved: The working layer thickness of the tundish plug area is set to 80mm, the working layer thickness of the impact area is set to 100mm, and the retaining wall thickness is set to 110mm; A composite ceramic plug with a ZrO2-C coating on the rod head surface is used; The mold slag used has the following mass fraction compositions: 5.69% F-, 32.83% SiO2, 38.17% CaO; Through the automatic control system, the slag line position is adjusted by 5mm every 15 minutes.

2. The method for increasing the number of continuous casting furnaces of the continuous casting tundish according to claim 1, characterized in that: The chemical composition of the protective slag also includes: 6.52% Al2O3 and 10.72% Na2O.

3. A continuous casting system for implementing the method for increasing the number of continuous casting furnaces using a continuous casting tundish according to claim 1 or 2, comprising a tundish, a stopper rod, a mold slag feeding device, and a slag line automatic control module, characterized in that: The working layer thickness of the tundish plug rod area is 80 mm, the working layer thickness of the impact area is 100 mm, and the retaining wall thickness is 110 mm. The stopper rod tip is coated with a ZrO2-C coating; The protective slag feeding device is equipped with the protective slag for feeding; The slag line automatic control module operates in a cycle of adjusting 5mm every 15 minutes.

4. The continuous casting system according to claim 3, characterized in that: The stopper rod is made of composite ceramic material.

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