Secondary cooling region support roll
The use of secondary cooling zones in steel rolling processes is a viable way to reduce cost and improve the product quality. The high temperatures experienced during the steel rolling process result in a product which is often out of specification, or not to the required tolerance.
In some processes, cooling process zones are used to reduce the temperature of the steel before it enters the rolling section. This can help ensure that the product is rolled in the optimum temperature range. This is especially important when rolling thin strips, as the optimal range increases progressively with thinner coating thickness.
Secondary cooling zones are often implemented for use in tandem with the primary cooling region, allowing for a more consistent product temperature and control over the product properties. The secondary cooling zone can aid in extracting or cooling heat as the steel passes from the primary cooling area to the rolling section.
Secondary cooling zones are implemented using a variety of different methods ranging from; water or another liquid based coolant, a cooled gas jet, or the use of an electrical induction system. The incorporation of secondary cooling zones can be expensive, depending on the system type and the complexity of the installation procedure.
The type of secondary cooling system used depends largely on the production requirements and then specific process in question. Usually, water or liquid based systems are more complex and expensive, but can be more effective at cooling higher temperature metals. However, gas jets and electrical induction systems are also viable secondary cooling methods, and may be preferable in certain processes.
Regardless of the type of secondary cooling system employed, it is important that the system is well maintained and operated reliably. The secondary cooling zone should be monitored closely, ensuring that optimal conditions are maintained at all times. The support roll used in the secondary cooling zone must also be selected with care.
Due to the particular conditions to which they are regularly exposed, the support rolls used in secondary cooling zones must be designed to cope with the varying temperatures and associated stresses. The material choice for the roll should be made carefully, considering life time and corrosion values as well as thermal stability. To further enhance the support roll’s properties, hardfacing and thermal spray coatings are often employed.
Additionally, special attention must be paid to the roll design, as the roll must remain suitably cool in order to absorb the heat of the product as it passes between the primary and secondary cooling zones.
In conclusion, the secondary cooling zone is an essential part of many rolling processes, and plays a key role in ensuring final product meets all specifications. The selection of the correct support roll which is tailored to an industrial process is imperative to maintaining a steady production rate and high product quality level. This requires careful consideration of materials selection and design parameters, helping bring the rolling process to its optimum performance.
