스테인리스 스틸 권취공정에서 강판 및 슬리브의 응력해석 모델 개발

Abstract

For the effective storage and transportation of a thin steel strip, it is coiled after the rolling process. During the coiling process, a sleeve with a mandrel must be used to prevent excessive deformation of the strip. Stress distribution in the sleeve and strip are important factors that determine the quality of the coil. However, experimental determination of this distribution is almost impossible because of accumulation of high pressure. In this study, an analysis model of the strip coiling process was developed. Also, the radial and hoop stress on the sleeve and strip were investigated. Theoretical values and analysis result in idealized conditions were compared for verification of the finite element model. Finite element (FE) analysis was used to investigate the effects of strip thickness on the stress distribution and mandrel and stress concentration. By applying the interference fit to the strip coiling process, radial stress with stacked thickness 384 mm that corresponds to strip length 1486 m was predicted. The result shows when reaction force was applied by the mandrel, the radial stress at the sleeve increased by 53.1%. It also increased by 4.37 times at the coil starting point for a strip 1 mm thick. Using the stress analysis result, FE analysis for the sleeve considering the shape of the mandrel and plastic deformation was conducted. From the result, the thickness of the sleeve can be reduced from 120 mm to 106 mm.