1983 Volume 69 Issue 9 Pages 1121-1128
To study the fracture mechanism of the refractories of blast furnace by thermal stress, a model furnace of hearth and bottom of Kakogawa No. 2 B. F. was constructed. The model furnace was heated to about 1 500°C, twice.
Thermal stress (strain), displacement of refractories and those of shell were measured during the heating test. Crack behaviour of the refractories was detected by A. E. during the heating test and also by visual inspection after the test.
The results are summarized as follows:
1. High stress was observed in refractories and in shell at the first heating test. The stress observed at the second heating test was less than that of the first. Also, displacement of shell and refractories was fairly affected by heat hysterisis. These phenomena may be caused mainly by irreversible shrinkage of joint mortal and carbon stamp.
2. Cracks were detected at side face of carbon blocks, by visual inspection. The result of A. E. signal indicated that these cracks probably occurred at the final stage of heating process of the first heating test.