Evaluation of hot deformation in foundry core sand using cupola furnace slag as additive

ABSTRACT

In this research, the effect of adding three types of cupola furnace slag in sand was evaluated on the hot distortion test. In addition, properties like as immediate tensile strength and tensile strength after 30 minutes were evaluated. Comparatively, mixtures with the addition of 8, 12, 20, 40 and 70% by weight of slag on silica sand from southern Brazil were evaluated for each type of slag. The results showed a reduction in the immediate tensile strength of the sand cores, regardless of the type of slag used. The addition of granulated cupola slag, duly processed, reduced the maximum hot deformation of the sand cores. It was also observed that the deformation was different for each type of slag used. In general, the best maximum deformation results were obtained for mixtures with 70% addition, followed by mixtures with 40% slag. The progressive addition of slag also reduces the deformation rate, with the green and black slag showing a 58% reduction. The results obtained in the hot distortion test showed a potential use of cupola slag to improve the performance of sand cores in relation to defects caused by the expansion of silica sand.

Keywords
Cupola slag; core sand; hot distortion