Comparison of different caster designs based on bulging,bending and misalignment strains in solidifying strand

Abstract

If the strain level in the solidifying strand is more than the critical strain limit, cracking occurs. This strain depends strongly on the caster design and the process parameters. In the present work, an attempt has been made to show the effect of various caster designs and process parameters on the bulging and bending strain in the continuously solidifying strand. For simplicity an analytical tool is chosen for the strain prediction. As the solidifying front is the most critical, strain is calculated on the solidifying front and therefore, the use of the hard box approach near the edges is not considered. Three different caster designs are considered for the comparison and the effects of casting speed, radius of the machine and roll pitch on the strains are studied. It is found that the misalignment strain is quite significant. The strong dependence of strain level on the rolls not in contact with the solidifying strand and the misalignment has highlighted the importance of good machine maintenance. A comparison between the prediction from the soft and the hard box approaches for bending/unbending strain is carried out and it is found that the soft box approach is more conservative for strain prediction.