April 19, 2022
Continuous casting machine production process. High temperature molten steel continuous casting to one or a set of water-cooled copper mold, steel along gradually solidified into a shell surrounding the crystallizer for liquid steel surface rises to a certain height, the shell solidification to pull machine will bloom out after a certain thickness, and the secondary cooling zone water spray cooling completely solidified billet, by cutting equipment according to the requirement of steel rolling cut to length. The process of casting hot steel directly into billet is called continuous casting. Its appearance fundamentally changed a century of dominance of steel ingot rolling process. Because it simplifies the production process, improves the production efficiency and metal recovery rate, saves energy consumption so that the production cost is greatly reduced, and the billet quality has been rapidly developed. In today's steelmaking enterprises, whether it is long process steelmaking or short process steelmaking, it is almost inevitable to equip continuous caster.
Continuous casting machines can be classified in many forms. According to the structure and shape, the caster can be divided into vertical caster, vertical bending caster, arc caster with straight section, arc caster, multi-radius elliptic caster and horizontal caster. With the development of continuous casting technology, the research of wheel continuous casting machine, especially thin slab continuous casting machine, has been carried out.
If according to the size and shape of the section cast by the caster, the caster can be divided into slab caster, billet caster, generous billet caster, round billet caster, special-shaped section caster and thin slab caster. In the billet caster also includes rectangular billet caster, usually the casting section or equivalent fault area is greater than 200×200mm called generous billet, the section or equivalent fault area is less than 160×160mm called small billet, width thickness ratio is greater than 3 rectangular billet called slab.
According to the number of billet flow that can be cast in a common ladle, the caster can be classified as single, double or multi-flow caster
General continuous casting machine is composed of molten steel carrier device (molten steel ladle, rotary table), tundish and its replacement device, crystallizer and its vibration device, secondary cooling zone holding roller and cooling water system, drawing straightening machine, cutting equipment, ingot leading device, etc. (figure below). Tundish plays the role of buffering and purifying liquid steel, the capacity is generally 20% ~ 40% of the capacity of molten steel ladle, the more the number of casting machine flow, the greater its capacity. Mold is the "heart" of continuous casting machine, requiring good thermal conductivity, rigid structure, wear resistance and easy to manufacture and maintenance, generally made of forged copper or cast brass, its outer wall forced uniform cooling water. The function of the mould vibration device is to make the mould vibrate periodically, so as to prevent the mould from being broken by the bonding between the mould shell and the mould wall. The vibration curve generally changes according to the sine law to reduce the impact, and its amplitude and frequency should be closely matched with the drawing speed to ensure the quality and output of the casting slab. The secondary cooling device is installed at the exit of the mold, and its function is to accelerate the solidification of billets and control the temperature of billets by means of water spraying or atomizing cooling. The clamp roller and guide roller support the high temperature billet with liquid core to prevent belly deformation or internal crack. At the same time, the technology of liquid core pressing down can be carried out in this section to improve the quality and output of the billet. It is required that the water pressure and water quantity of the secondary cooling device can be adjusted to meet the needs of different steel types and different drawing speed. Machine's role is to provide the throwing power and the bending of the slab straightening, movement and promote cutting device, throwing speed have great influence on quality of continuous casting production, and the function of dummy device is in before the start of continuous casting, using dummy head mold under the mouth, after waiting for molten steel solidification to pull lead slab casting machine, and then release the dummy head, the income of dummy bar storage device. Casting billet cutting equipment will be continuous movement of casting billet cutting into fixed length, commonly used cutting equipment is flame cutter or hydraulic shear and swing shear.