The No. 1 Caster at LTV Steel - Cleveland Works was experiencing off-corner, narrow face breakouts during widening width changes at a rate of three per year. The loss of narrow face support during the width adjustments has historically been the single greatest cause of breakouts. An interim measure of increasing narrow face taper from 0.89% per meter of mold length to 1.22%/meter (for wide slabs) and up to 1.50%/meter (for the narrowest slabs) has provided sufficient support during widening to eliminate this type of breakout. University of Illinois finite element model simulations revealed that insufficient narrow face taper alone cannot cause a shell thinning breakout during a widening width adjustment. However, when combined with high superheat, biased flow in the mold, or a misaligned/off-centered submerged entry nozzle, the loss of narrow face taper can lead to retarded shell growth and enough thinning to result in a breakout. The model confirmed the effectiveness of increased narrow face taper in reducing shell thinning. It was used to examine width change practice options in preparation for system automation.
ASJC Scopus subject areas
- Metals and Alloys