The strains present during the continuous casting process consist of three basic mechanisms:
- Bulging strains, εB
- Bending/Straightening strains, εBS
- Misalignment strains, εM
These can simply be combined to give the total strain, ε at the solidification front using the following equation (note that the five point straightening method [εBS5] was used to evaluate the total strain in this exercise):
ε = εB + εBS + εM
The strains individual can be calcualted respectively:
This exercise demonstrates the effect of altering the various casting parameters on both the individual and total strains present. Use the input boxes to simulate the various stages in the casting path to evaluate the required roll spacing at each respective point in order to achieve the minimum total strain in the cast bar. You may also wish to consider what an acceptable tolerance for the roll positioning would be (roll misalignment), as very tight tolerances may result in much greater equipment and maintenance costs.
Note: to calculate the total strain in this exercise a five point straightening method was used to evaluate εBS, where roll 56 represents a constant radius (i.e. zero bending/straightening strain) and rolls 57-60 are the bending/straightening rolls.
Where:
S = k √t
Using the solidification factor, k; where time since casting began, t is given by:
t = h / Vc
References
- AISE, The Making, Shaping and Treating of Steel - Casting Volume CD, The AISE Steel Foundation,
- Bernhard, C & Sjökvist, T, Die interaktive Stranggießsimulation auf www.steeluniversity.org Berg- und Hüttenmännische Monatshefte, SpringerWienNewYork, 0005-8912
