Continuous casting of liquid steel was introduced to commercial use in the 1950s. In the steel rolling industry, the familiar continuous casting machine is the production process of continuous casting.
Continuous casting is the solidification of molten steel into semi-finished steel products such as billets, blooms and slabs. The process of subsequent rolling of steel billets using a hot rolling mill.
Continuous casting can increase the productivity of the production line in the same amount of time. The quality of the final cast steel product is also very good.
On rolling lines, the use of continuous casters enables high casting speeds. The casting speed will be limited by some conditions.
High casting speeds lead to a significant increase in the flow rate of molten steel in the mold.
Any slight disturbance of the molten steel flow will interfere with the formation of a solidified shell within the mold, hinder the floatation of inclusions, and may result in the entrainment of powder in the strand.
The fluctuations at the mold meniscus get worse as the casting speed increases. This can lead to quality problems or even cracks on the slab surface.
This problem can be solved by changing the nozzle design, applying electromagnetic stirring, changing the casting powder, and using other methods to control the flow pattern in the mold.
High casting speeds lead to excessive axial strain caused by the oscillation and withdrawal forces required to overcome friction at the interface between the solidified shell and the mold.
At high casting speeds, the ferrostatic pressure of the liquid pool under the mold may create excessive membrane strain in the thin shell. If the shell is not thick enough at the exit of the mold, this can lead to cracks and cracks.
For most steel grades, the critical shell thickness must be around 3 mm. This is easily achieved with any feasible casting speed, suggesting that other criteria are more important.
If we can deal with these details, we can make good use of the continuous casting machine process. These can have a huge impact on our production operating costs, enabling significant quality improvements in our continuous cast products.