Abstract:According to the high metal consumption of large-scale semi-autogenous grinding (SAG) system, the modification effect of nano-modification technique on the microstructure of carbidic austempered ductile iron (CADI) grinding ball have been investigated. The results indicate that with the increase of the nano-modifier, the size of the graphite ball in CADI grinding ball is reduced, circularity increased, the number of graphite spheres are increased; similarly the carbide has highr dispersion degree, finer size. High-temperature pretreatment reduce the number of carbides, passivate boundary, transform short rods into round. The optimized microstructure is fine and uniform, which is very beneficial to improving abrasion resistance and crushing resistance of grinding balls.