Numerical Study Of The Liquid Core Reduction For Thin Slab Continuous Casting

Liquid core reduction (LCR) in thin slab continuous casting is a novel continuous casting technology, which combines solidification with large plastic deformation, continuous casting with direct rolling in a single process. This new technology has apparent advantages of energy-saving, reduction of process flow and high product quality. It can also solve the problem which matching thickness between thin slab continuous casting and direct rolling. So the technology has become the highlight in modern metallurgical industry and is sure to be one mainstream in continuous casting technologies. About LCR of thin slab continuous casting, this paper is concerned with following research aspects:Theory of solidification and heat transfer is introduced in thin slab continuous casting. Then strength of thin slab is analyzed. Basic principle, primary parameter, control model of LCR in thin slab continuous casting is described.According to the actual situation of thin slab casting product line in Tangshan Iron and Steel Company, craft parameters on reduction of the liquid core are introduced. Under the premise of reasonable simplifications and assumptions, a three-dimensional finite element model of LCR process has been developed. Thermal and displacement boundary conditions are determined. Based on elastic-plastic theory, LCR technology was studied with the aid of commercial finite element software-MARC.By numerical simulation of LCR process, the temperature field, solidification of thin slab, deformation characteristics and distribution of strain-stress are obtained during LCR continuous casting. The results are in line with actual production.This paper also researched the influence of craft parameters i.e. secondary cooling system and reduction volume on the distribution of temperature field as well as stress and strain. The basic principles which must be considered to determine craft parameters of LCR are obtained.The external part of the solidified shell is under the compressive stress state, and the internal part is under the tensive stress state, so internal crack is engendered easily. The strain of the solidification forefront can't exceed the critical strain to prevent the formation of crack.The research results demonstrated that choosing craft parameters of LCR reasonably is an important means to control the stress and deformation of the slab, prevent the internal crack and make implementation of LCR successful. The simulation results supplies a reasonable base for real production in this paper.