Study of the Influence of Modification and Heat Treatment of Cast Iron Grinding Balls on Their Operational Properties

The study addresses the enhancement of wear resistance and impact strength of cast iron grinding balls used under intensive abrasive wear and impact conditions at ore processing plants. The primary aim is to improve the operating properties of cast iron by optimizing its chemical composition and introducing advanced thermal and chemical-thermal treatment methods, including controlled cooling. To achieve this goal, two alloyed cast iron compositions with added chromium, molybdenum, and nickel were used, and the base composition was further modified with titanium and titanium carbonitride to increase the microhardness of the matrix phases. Experimental samples underwent various heat treatment regimes, including quenching and normalization, to evaluate the effect of these processes on the microstructure, hardness, and impact resistance of the grinding balls. Microstructural analysis revealed that additional alloying elements and modifiers contributed positively to forming a more homogeneous and fine-grained structure with an increased proportion of carbide phases. The key findings indicated that the optimized structure of the cast iron grinding balls achieved 10 units higher hardness and 2-4 units greater impact resistance than the base composition after heat treatment. Furthermore, titanium and titanium carbonitride modifications enhanced the performance characteristics of the balls by several additional units. Thus, the developed treatment regimes and modified cast iron composition significantly increase the wear resistance of grinding balls, contributing to reduced grinding costs in industrial applications.