Thermal Stress Analysis of Fused‐Cast AZS Refractories during Production: Part I, Industrial Study

Abstract

A study has been conducted to understand and prevent the formation of cracks in alumina‐zirconia‐silica (AZS) refractory blocks during solidification processing. A fundamental approach has been taken, centered on the development of a three‐dimensional mathematical model to predict heat flow and stress generation in fused‐cast AZS refractory blocks. In the first part of a two‐part study, the “voidless” casting process has been carefully examined in an industrial setting. From a survey of the distribution, frequency of occurrence, and fracture surface morphology of cracks, an attempt was made to link the crack types found in the study to process variables. In‐mold temperature data collected for a single casting throughout the normal cooling period have been used to validate the heat‐flow model which is described in Part 11. The stress analysis, cause of the different cracks, and remedial action are also presented in Part 11.