Dynamic Distributions of Mold Flux and Air Gap in Slab Continuous Casting Mold

• Published in: ISIJ International Vol. 59; no. 2; pp. 283 - 292
• Main Authors: Niu, Zhenyu, Cai, Zhaozhen, Zhu, Miaoyong
• Format: Journal Article
• Language: English
• Published: The Iron and Steel Institute of Japan 15.02.2019
• Subjects: air gap; heat transfer; mold flux film; simulation; slab continuous casting
• ISSN: 0915-1559; 1347-5460
• DOI: 10.2355/isijinternational.ISIJINT-2018-609

The distributions of mold flux and air gap in shell/mold gap have significant influences on the shell heat transfer in slab continuous casting mold. To describe the dynamic distribution characteristics of the mold flux and air gap, a three-dimensional thermo-mechanical model coupling with a complex interfacial heat transfer model was developed, in consideration of the interactions between the thermo-mechanical behaviors of solidified shell and distributions of mold flux and air gap. Based on these, the contact and heat transfer behaviors between the shell and mold copper plates, as well as the influence of wide face mold taper on the distributions of mold flux and air gap during a peritectic steel continuous casting were studied. The results show that the temperatures of copper plate hot faces beneath the bolt columns are higher than those beneath the deeper channels, and the calculated temperatures of copper plates coincide well with the measured data by thermocouples. Due to the thermal contraction, the shell corners in mold shrink away from mold corners as the slab moving downward, which causes the thick mold flux film and air gap concentrate around the corners and off-corners. As a result, the hot spots form at the shell off-corners. With greater wide face tapers, the thicknesses of mold flux film and air gap at wide face corner decrease. When the wide face taper increases to 4 mm, the air gap on shell wide face corner disappears near the mold exit.