| 摘要 |
PROBLEM TO BE SOLVED: To predict and prevent generation of scratch flaws in a strip body by judging a buckling when the circumferential stress exerted in a roll which is calculated based on the temperature distribution in the axial direction of a conveyance roll in a furnace exceeds the buckling limit of the roll. SOLUTION: The wall thickness (t) of a roll which is free from buckling is obtained from a formula III based on the buckling limit circumferential stressσθk expressed by a formula I and the roll circumferential stressσθexpressed by a formula II. In the formulae, E denotes Young's modulus (kg/cm2);νdenotes Poisson's ratio; (t) denotes the thickness (mm) of a shell of a hollow conveyance roll; (r) denotes the radius (mm) of the hollow conveyance roll;αdenotes the heat conductivity (w/mm2.K) of the conveyance roll; T1 denotes the lowest temperature ( deg.C) of the conveyance roll; T2 denotes the highest temperature ( deg.C) of the conveyance roll. In the case of the steel conveyance roll, E=14,400 kg/mm2,ν=0.3 andα=1.6×10-6 are preferable. The highest temperature of a strip body to be conveyed, and the atmospheric temperature in a furnace in which the conveyance rolls are arranged can be used for T2 and T1, respectively.
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