Conversion from Curved to Straight Mold: New Revamping Concepts and Quality Improvements

摘要

Many slab caster revamping orders are currently placed by steel producers in order to increase the plant production as well as the quality of the cast product. Since the last 10 years all slab casters that were originally supplied with curved molds are modified to straight mold machines whenever a machine revamp is necessary. Internal slab cleanliness is one of the most critical quality requirements for ultra low carbon (ULC) steel grades for high level applications like exposed automotive panels or extra deep drawing purposes (beverage cans, oil filter housings). Non-metallic inclusions or argon bubbles that are unable to float up in the mold are entrapped by the solidifying strand shell of the inner radius. Especially curved mold casters are sensitive to this so called "quarter-band" inclusions because of the short vertical length.