The Influence of Cooling Rate and Equivalent Carbon on the Chill Tendency and Cooling Curves Parameters in Uninoculated and Inoculated Grey Cast Iron

摘要

The main objectiv of this experimental research is a comparative analysis of the changes caused by varying cooling rate and carbon equivalent content on chill tendency and cooling curves parameters in grey cast iron. Two irons with different carbon equivalent content were developed in this experiment. Cylindrical samples having a slight conicity were poured in furan resin sand moulds in which metallic cylindrical shells with different wall thicknesses (δ=0mm, δ=2mm, δ=5mm, δ=8mm, δ=11mm, δ=14mm) were incorporated (K type thermocouples incorporated) with the purpose of varying the cooling rate (Fig. 1). Both uninoculated and 0.3wt.% FeSiCaBa inoculated irons were poured into sand moulds. The variation of cooling curves parameters under the influence of the two factors (cooling rate and equivalent carbon) were studied for a better understanding of the cast iron solidification mechanism. Two experimental programs were developed in this reason. The experimental results show significant variations both of the conventional cooling curves parameters and grey irons chill tendency under the influence both of the cooling rate, carbon equivalent and inoculation state.