Influences of Cr on the microstructural, wear and mechanical performance of high-chromium white cast iron grinding balls

Abstract

High-alloyed white cast irons are widely used by casting methods to produce grinding balls used in the cement and mining industry. Balls produced in this class are in the high chromium white cast iron class, and the chromium content in this material has a significant effect. This study on improving quality and competitive conditions in ball production aimed to obtain balls with the same mechanical properties and to investigate their performance by reducing the Cr ratio of the sample with 17-19% chromium (Cr) content. In this context, studies have been carried out by reducing the amount of Cr in the ball by performing oil-quenching heat treatment instead of the air cooling system used within the company. The samples' wear amount, hardness, toughness and microstructure were evaluated by reducing the Cr content. Since reducing Cr atoms cause the carbide phases in the balls to decrease and the martensite ratio to increase, materials with the same wear resistance have been obtained. The same mechanical properties as the existing mass-produced balls with a Cr content of 17-19% were determined by reducing the Cr content to 10%. As a result, a significant reduction in raw material cost has been demonstrated by producing balls with the same mechanical properties suitable for working conditions.