Slab dishing factors and improvement measures

Slab dishing factors and improvement measures mainly in the following areas:

1, the steel composition
When the carbon content in steel peritectic reaction space, due to the large volume of peritectic reaction will change, linear shrinkage, contraction and solidification of molten steel static pressure uneven effect, make the thin solidified shell surface roughness, wrinkles, severe form depression. It should test peritectic contraction extreme C, adjusting the steel composition to avoid this extreme value.
2, cooling system
Slab Depression is caused due to local contraction caused by uneven cooling. Mold cooling is strong, easy to increase the slab depression. It should be appropriate to reduce the mold cooling water to suppress blank shell premature contraction, improve slab depression.
3, flux
Since the shrinkage characteristics of the steel, solidified shell mold surfaces may sag, therefore, the design of low-carbon peritectic steel powder composition, to ensure a high melting point, high viscosity, high alkalinity (high crystallization temperature).
4, points to the
If the outlet for the poor, the installation location biased or within arc outside the arc, then make that impact site appears remelting solidified shell, shell thickness caused by uneven depressions or cracks generated local stress concentration. Therefore, to improve the nozzle assembly requirements, to ensure that the outlet of the well.
5, mold taper
Mold taper is designed to compensate for shrinkage of the solidified shell, and improved thermal conduction and thermal radiation between the solidified shell and the mold wall air gap. Found inverted parabola taper brass mold, and then to make up for the effect of shell contractions well.
6, mold level fluctuation
Mold level fluctuation especially the stability of the meniscus fluctuation is subsequent slab surface quality of the key factors, the production, mainly to achieve the effect by automatic level control.
7, the production rhythm
Good production rhythm, to avoid overheating of the casting speed mismatch problems, make good quality slab surface.