All You Need To Know About Refractory Tundish Well Block

In steelmaking industries, the continuous casting process requires a refractory tundish well block. The tundish is positioned between the ladle and mold so that it can distribute the molten metal in an organized way. The block gets installed at the bottommost part of the tundish. There are some key reasons to use well blocks. Let's have a look at them.

Tundish Well Block: Key Functions

• Offers support to the stopper rod and nozzle

The molten steel needs to flow to the mold through a nozzle. The tundish well block holds it and makes the alignment correct. It also controls the rate of flow by facilitating the stopper’s movement.

• Prevents Leakage in the Steel Body

The well blocks are manufactured using supreme quality refractory resources. This makes them potent to seal the nozzle tightly and prevents steel leakage.

• Offers resistance against corrosion and high temperatures

Molten steel remains exceptionally reactive and hot. So, the manufacturers prepare well blocks to offer resistance to corrosion and high temperatures.

• Increases Casting Efficiency

AA refractory tundish well block is used for the improvement of the cast products’ quality by offering minimal turbulence and smooth metal flow.

Materials Used To Manufacture Tundish Well Block

As well, blocks are used to handle molten steel; they must withstand corrosion, high temperatures, and thermal shocks due to their closeness to it. You can choose the materials depending on the tundish design, grade of the steel, and casting conditions.

Here are the commonly used refractory materials discussed below.

• Al2O3-based refractories

Offers high-quality wear resistance and thermal resistance and enough slag resistance. The general steel casting method uses a moderate amount of thermal shock, so high alumina-based refractories are used here.

• MgO-based Refractories

Offers excellent resistance to basic slags and high temperatures and a decent thermal stability. It is used in those applications where slag resistance plays a crucial role, like high-carbon alloy steel casting.

• MgO-C Refractories

It uses carbon and magnesia, which are great together to offer resistance to high temperatures and slag penetration and excellent mechanical strength. Magnesia-carbon refractories are used.

• ZrO2-based Refractories

It offers exceptional chemical resistance and thermal stability with low expansion in high temperatures. Commonly used for the casting of ultra-low carbon steel and stainless steel, which are actually high-quality grades of steel.

• SiC Refractories

It contains alumina or carbon and silicon carbide. It offers resistance to thermal shock, erosion, and wear and high thermal conductivity. It is best used in applications requiring high durability.

• MgO-Al2O3-based Refractories

It offers resistance against slag and corrosion and outstanding mechanical strength. It is generally used in aggressive casting environments such as high-performance refractory tundish well blocks.

How To Select The Materials?

There are a few measures to consider when choosing which materials to use for refractories. Key points are discussed below.

Grade of the Steel—For highly pure steel, low-contamination materials are required. Example—zirconia.

Duration for Casting—For long-duration casting sequences, highly durable materials are required. Example—Magnesia-Carbon.

Thermal Cycling—High-temperature shock-resistant materials are required in recurrent heating and cooling. Example—Silicon Carbide.

Slag Chemistry—Alumina-based refractories are used in acidic slags, and magnesia-based refractories are used in basic slags.

Types of Refractory Tundish Well Blocks

Depending on the design features, manufacturing process, and composition of materials, tundish well blocks can be classified in different ways. The selection process will depend on the tundish design, casting conditions, and steel grade. Here are the key categories at a glance.

1. Material Compositio

• High Alumina Well Blocks (Made Of Al₂O₃)

• Magnesia Well Blocks (Mgo)

• Magnecia Carbon Well Blocks (Mgo-C)

• ZirconiaWell Blocks (ZrO₂)

2. Manufacturing Process

• Monolithic Well Blocks

• PrecastWell Blocks

• PressedWell Blocks

3. Shapes & Design

• Standard Well Blocks

• SlottedWell Blocks

• Customized Well Blocks

So, before choosing the right well block for your application, don't forget to consider casting types, material compositions, nozzle types, resistance to erosion and high temperatures, steel grade requirements, operational cost, and supplier specifications.