Material and Structure of Tundish Impact Pot

Characteristics of a Tundish Impact Pot:

A tundish impact potplays two main roles in continuous casting operations at steel plants: 1. Ensuring the internal and surface quality of the cast product; 2. Improving production efficiency and reducing downtime during production.

Basic Principles of Tundish Impact Pot Design:

The basic principle of designing a high-efficiency tundish impact potis to utilize fluid mechanics principles and, through reasonable structural design, control the flow direction and velocity of molten steel within the tundish, thereby achieving goals such as flow stabilization, slag removal, and temperature reduction.

In impact potdesign, fluid mechanics is a crucial theoretical foundation. By analyzing the flow patterns of molten steel within the tundish, the optimal impact potstructure can be determined, improving flow stabilization and reducing steel loss. Numerical simulation technology can effectively predict the flow state of molten steel within the tundish, helping designers optimize the impact potstructure, improve its performance, and shorten the design cycle.

Key Factors for Tundish Impact Pot Structure Optimization:

1. The influence of immersion depth on the flow field. Immersion depth refers to the depth to which the impact potis immersed in molten steel. Different immersion depths affect the steel flow velocity and direction, thus impacting the flow stabilization effect.

2. Aperture Design and Flow Control. The aperture diameter and number on the impact potdirectly affect the steel flow rate. A reasonable aperture design can effectively control the steel flow velocity, preventing steel deviation and inclusions.

3. Influence of Tundish Impact Pot Shape on Flow Field. Different impact pot shapes produce different flow fields, affecting the flow pattern of molten steel. A suitable shape needs to be selected based on the steel grade and production requirements. Impact pot  are generally square, rectangular, or circular. The shape of the impact pot  mainly depends on the shape of the impact zone. The thickness of the bottom of the impact potshould be determined based on the tundish's service life, tundish liquid level, number of consecutive castings, and the distance from the bottom of the long nozzle to the ladle bottom. Generally, if the tundish has a long service life, a low tundish liquid level, and a large number of consecutive castings, the impact potwill wear out quickly and should be thicker. Conversely, it can be thinner.

4. Temperature field distribution is a crucial factor affecting billet quality. A well-designed impact potcan achieve a more uniform temperature distribution in molten steel, reducing internal defects in the billet.

5. Inclusion trajectory analysis. Inclusions are one of the main factors affecting billet quality. By studying the movement trajectory of inclusions within the tundish, the impact potdesign can be optimized, improving slag removal efficiency.

Currently, most impact pot employ porous and guide channel structures. Porous impact pot, by designing multiple small holes on their surface, can effectively control the molten steel flow rate and direction, improving flow stabilization and reducing steel loss. Guide channels are an important component of the flow stabilizer; optimizing their shape and size can guide the molten steel to flow uniformly, improving flow stabilization.

impact potmaterial selection.

The refractory materials selected for the impact potmust meet performance requirements such as high refractoriness, high corrosion resistance, and low thermal conductivity to ensure the service life and performance of the flow stabilizer.

Material selection should be based on the structural thickness and the service life of the tundish. Currently, our company primarily uses an alumina-magnesia raw material system. We employ sintered magnesia of varying particle sizes and premium high-alumina powder as aggregates, medium-grade magnesia powder and premium high-alumina powder as the matrix, and add a certain amount of binder. During use, at 1200~1300℃, A0⁻⁶ reacts with MgO to form magnesium aluminum spinel, which has excellent resistance to slag penetration, effectively preventing slag from penetrating the product. The product does not form segmented structures, therefore, structural stress will not cause product spalling during use.