Mar 14, 2017
Other factors effect grinding balls are as followings:
Molybdenum (Mo): Molybdenum’s role is matrix refinement. It can refine carbide, improve the electrode potential of matrix and balls corrosion resistance. In the metal casting conditions, adding a small amount can take effect, it mainly used for special grinding ball.
Sulfur (S): Due to the high content of manganese in steel, large amount of MnS generated and discharged from the slag. But because it is melted in basic slag, the sulfur can be successfully reduced to 0.03%. Such a low sulfur content will not significantly affected the steel strength, toughness and wear resistance.
Phosphorus (P): Phosphorus rarely dissolved in the steel separately, it often reduces the steel strength, toughness and wear resistance as Fe2p, Fe3P form on grain boundaries. High content carbon increase phosphorus precipitation in form of eutectic crystal. In order to guarantee grinding media balls performance, it should follow the below relationship: C% = 11.27-2.761 × P%. Make sure the phosphorus content ≤0.08% in production, and important, complex and thick pieces≤0.07%.
Silicon(SI): Silicon is an important element for grinding ball, it is not only effectively reduce the chilling tendency and increase the amount of ferrite, but also refine eutectic and enhance ball roundness. However, silicon also improve brittle transition temperature of cast iron, thus reduce the impact toughness. Therefore, the silicon content should not be too high, especially for situation that the cast iron manganese and phosphorus content is higher.