Optimizing of Dimensions of Flat-ingot Mould on the Basis of Thermal Stress Analysis

Abstract

Thermal stresses originated in ingot moulds during solidification of ingots in contact were analyzed by the two dimension thermo-elastic theory. The unsteady temperature distribution was estimated using a finite difference method on the nodal points of mesh screen representing a mould cross section. The thermal stress distribution on imaginary dividing elements of the mould was subsequently calculated by a finite element method. A thermal stress parameter, the ratio of the thermal stress in an element to the tensile strength of the element, was then calculated to investigate the influence of the thermal stress on the life of the mould.
A subsequent analysis was made of the thermal stress parameter for flat shape moulds with different ratios of cross section of the mould to that of a corresponding 23 tingot and with differeat ratios of the wide-face thickness to the narrow-face thickness of the mould.
The above analysis has made it possible to derive an optimum mould shape, for which thermal stress becomes minimum, for the flat shape 23 t ingot.