Improved Riser Material Efficiency of Massive Steel Casting by Using a New Type of Sleeve

From the perspective of reducing the carbon footprint, yield improvement is seeing global interest. One possibility to achieve this goal is to influence the volume of feed metal in the molds to achieve a sound casting. The largest volumes of risers are used in steels, so the research has focused on carbon steels for castings. Typically, to reduce the amount of molten metal in the riser, sleeves are used, such as exothermic and insulating ones. However, this is no longer sufficient, and therefore, blends of sleeves have been developed that perform both exothermic and insulating functions. The use of a new and innovative two-layer sleeves, combining the advantages of both layers (inner layer exothermic, outer layer insulating), proves to be highly effective. The conducted experiment compares this new approach with commonly used sleeves (exothermic, insulating, and exothermic—insulating). The utilization of riser metal using the new two-layer sleeve showed to be 8–10% higher compared to standard exo—iso mixed sleeves, and compared to single-layer inserts, the utilization of molten metal was 18–20% higher.