2018 Volume 58 Issue 3 Pages 521-526
In the continuous casting process of steels, the mold flux infiltrated in between a mold and solidified shell plays an important role to optimize lubrication and heat transfer to establish not only stable operation but also good surface quality of slabs. Therefore, lubrication and heat transfer was evaluated by measuring friction force attributed to the mold oscillation along with a lubrication model. The friction force was measured with a slab caster equipped with hydraulic oscillators, to understand how the friction force was affected by continuous casting factors such as the mold oscillation conditions, mold flux properties and casting speed.
It was found that the friction force was proportional to the velocity of the slab relative to the mold. The lubrication condition behaved as if it was fluid with the casting speed higher than 1.4 m/min.
In addition, the temperature dependence of viscosity of the molten flux was accounted for to develop a new fluid lubrication model. The present model showed that the lubrication layer thickness was approximately 50 µm.
Further, heat transfer through the mold flux was evaluated by the lubrication model revealing thermal resistance of the solidified flux layer, proving that the resistance caused by the crystallized flux was larger than that by glassy flux.