Vertical semi-continuous casting (VERSCON) is a viable alternative solution to ingot casting for smaller production units in the range of 50,000 to 200,000 t/y. The vertical semi-continuous casting process is not a new, but a practical concept.
In semi-continuous casting, section sizes start typically at a diameter of 400mm (~1 t/m strand weight) and reach up to ~1400mm (12 t/m strand weight) and or more. Mostly round sections are foreseen since these sections do not require a long containment. For casting of non-ferrous metals such as aluminum and copper, the process is already a standard application. However, the adaption of such a plant concept to the casting of steel adds increased complexity due to the slower solidification rate of steel.
The driving idea behind the semi-continuous casting concept is the requirement to cast one or two ladles on one or more strands into long blooms. The process is basically done in two steps:
- Continuous casting of a long bloom with conventional mold and oscillation table
- Casting stop, when the strand has reached its final length. The strand is held in position until final solidification is achieved, which can extend over many hours depending on the section size.