Study of erosion phenomena in sand moulds poured with cast iron

Abstract

Within the framework of the present study, a pilot stand has been designed for investigation of erosion phenomena in sand moulds poured with cast iron. The study comprises an evaluation of erosion resistance of the sand moulds with different types of binder, angle of molten iron jet incidence, degree of moulding sand compaction and temperature of metal when it strikes against the mould surface. A method for quantitative determination of the erosion resistance of sand moulds has been developed, based on the volume of the protrusion built up on a flat casting surface per unit volume of molten metal flowing along the erosion-deformed surface. Erosion is particularly intense for sands with organic binders, both at the point of metal impact and along the route of the flowing metal. The as-cast surface quality can be improved by increasing the level of mould compaction. Sodium silicate bonded moulds are more resistant to the erosive effect of the metal jet, although the destruction of bridges between the sand grains can lead to rougher casting surfaces. Again this roughness can be reduced by a high degree of compaction or by using protective coatings.