Overview of billet continuous casting machines
Billet continuous casting machines are important equipment widely used in the metallurgical industry. Their main function is to cast molten steel into billets with square or nearly square cross-sections, which are then rolled into various steel products such as rebar, wire rod, steel section, bar, tube billet, and strip. According to the different cross-sectional dimensions of the billet, billet continuous casting machines can be further divided into small billet continuous casting machines and large billet continuous casting machines.
Classification standards for billet continuous casting machines
Usually, the cross-sectional dimensions of billets produced by small billet continuous casting machines are less than 220mm×220mm; while large billet continuous casting machines are suitable for billets with cross-sectional dimensions greater than 220mm×220mm. In addition, continuous casting machines with rectangular cross-sections and an aspect ratio of less than 2.5 are usually also classified as billet continuous casting machines, and are collectively referred to as “billet continuous casting machines” in the industry.
Characteristics of billet continuous casting machine
Since the billet cross-section of the small billet continuous casting machine is small, the billet shell formed in the crystallizer has good rigidity, so the billet is not prone to bulging during the continuous casting process. Especially under the process conditions of using rigid ingot guide rods, good support is required to ensure the stability of the billet in the upper area of the guide section of the secondary cooling zone. For cross-sectional dimensions below 220mm×220mm, the support effect can be enhanced by increasing the number of foot rollers to prevent the billet from deforming.
When the cross-sectional dimensions of the billet increase and it is difficult to provide sufficient support force with foot rollers alone, it is necessary to learn from the design ideas of the slab continuous casting machine and use a close-packed roller structure in the upper part of the guide section of the secondary cooling zone to fully support the four sides of the billet to prevent it from bulging and deformation. This structural design is an important feature that distinguishes the large billet continuous casting machine from the small billet continuous casting machine.
The main difference between billet continuous casting machine and slab continuous casting machine
Whether it is a small billet or large billet continuous casting machine, when the billet solidifies in the secondary cooling zone and forms a box-shaped structure with sufficient rigidity, the guide section below this area can be simplified, and only needs to provide a guiding function without having to bear additional support tasks. This structural optimization not only simplifies the equipment design, but also reduces the manufacturing and maintenance costs.
In the billet straightening machine part, the billet continuous casting machine mainly considers the billet drawing force, straightening force and deformation rate, without the need for a complex support structure like the slab continuous casting machine. This simplified structure gives the billet continuous casting machine certain advantages in terms of process layout and equipment cost.
