The application of boron nitride ceramic in horizontal continuous casting
Horizontal continuous casting(HCC) is a commonly used process in metal material production for continuous production of long cast products such as copper, aluminum, steel, etc. The main principle of this process is to inject molten metal from a furnace into the crystallizer of a continuous casting machine, where it gradually solidifies and forms a continuous cast billet through proper cooling and solidification processes.
The main steps of horizontal continuous casting include:
1.Melting and preheating: The metal material is first melted in a furnace and maintained at the appropriate melting temperature.
2.Injection: The molten metal is injected into the crystallizer of the continuous casting machine through an injection system. The injection system typically consists of one or more nozzles that control the flow rate and speed of the metal.
3. Solidification: The metal gradually cools and solidifies in the crystallizer, forming a continuous cast billet. The crystallizer is usually equipped with cooling water pipes to accelerate the cooling process.
4. Withdrawal: The cast billet is continuously withdrawn from the crystallizer by a withdrawal mechanism at a constant speed. The withdrawal process helps further control the shape and dimensions of the cast billet.
5. Cutting: The continuous cast billet can be cut into the desired lengths at appropriate positions, according to the requirements.
The application of boron nitride ceramic in horizontal continuous casting is mainly for the use of break rings:A break ring is used as the joint between mold and tundish. The break ring works to keep a starting position of solidifying front constant, similar to meniscus in conventional continuous casting mold.Moreover, this starting position is kept constant by mechanical separation of solidified shell by applying proper thermal conditions around the break ring and suitable withdrawal pattern mode. These factors can prevent a breakout and permit stable withdrawal of cast strand.
Therefore, the essential properties for the break ring and crystallization tube are:
1.Resistance to chemical corrosion from the molten metal.
2.Low wettability by the molten metal.
3.High wear resistance.
4.High resistance to thermal shock.
5.Low thermal conductivity.
6.Good machinability.
In terms of chemical corrosion resistance, non-wettability, resistance to thermal shock, and machinability, single-phase boron nitride (BN) is the best choice. However, when pouring a large amount of steel, it causes significant mechanical wear. In such cases, it is necessary to use composite boron nitride materials to improve wear resistance and resistance to thermal shock. Due to the corrosive nature of high-alloy steels towards ceramic materials containing a large amount of SiC and Si3N4, they generally do not perform well in continuous casting production. The use of BN-ZrO2 materials is much better and effectively reduces the corrosion of high-alloy steels on the break ring. Here is a performance table for BN-ZrO2 materials produced by MASCERA:
| Material Type | BN-D |
|---|---|
Main Content | BN+ZRO2 |
Color | Dark Grey |
Density (G/Cm3) | 2.8-2.9 |
Flexural Strength (Mpa) | 90 |
Compressive Strength (Mpa) | 220 |
Electrical Resistivity (Ω.Cm) | >1012 |
Max. Service Temp. (℃) @Air Condition | 900 |
Max. Service Temp. (℃) @Vacuum Condition | 1800 |
Max. Service Temp. (℃) @Inert Gas Condition | 1800 |
Thermal Conductivity (W/Mk) | 30 |
Thermal Expansion Coefficient (25 - 1000℃) (10-6/K) | 3.5 |
XIAMEN MASCERA TECHNOLOGY CO., LTD. is a reputable and reliable supplier specializing in manufacturing and sales of technical ceramic parts. We provide custom production and high precision machining for a wide series of high performance ceramic materials including alumina ceramic, zirconia ceramic, silicon nitride, silicon carbide, boron nitride, aluminum nitride and machinable glass ceramic. Currently, our ceramic parts can be found in many industries like mechanical, chemical, medical, semiconductor, vehicle, electronic, metallurgy etc. Our mission is to provide the best quality ceramic parts for global users and it is a big pleasure to see our ceramic parts work efficiently in customers' specific applications. We can cooperate on both prototype and mass production, welcome to contact us if you have demands.
