Estudio numérico-experimental sobre la influencia del tamaño, forma y composición en mazarotas con camisas exotérmicas aplicadas a la fundición de hierro dúctil.

Abstract

Using exothermic sleeves allows to reduce the volume of the risers required in the casting of ferrous alloys, as well as the amount of metal used, and the costs involved. In this work, flat plates of nodular iron were casted, and the effects of the shape and size of the risers was analyzed. For this purpose, risers with two configurations (with and without exothermic sleeves), three shapes (cylindrical, spherical, oval), and two relative sizes (100 % volume and 60 % volume) were considered. The mixture that would experience a thermite reaction with the highest temperature was defined. Experimental tests and computational simulations were performed, indicating that the spherical sleeves result in the lowest porosity in the risers and the pieces. It was also found that the risers with exothermic sleeves and 60 % of the base volume used satisfy the feeding requirements and reduce the defects in the piece.