Abstract

This work deals with production of different sizes of grinding balls from high-
Cr-iron alloy . Cr contents range between (14-16) wt% carbon content (2.1-
2.4)wt% and Mo content (0.3-0.4)wt% ,those balls used in grinding cement and the
materials used in its manufacturing . Many heat treatments had been done on the
balls to show thier effects on hardness and microstructure. Balls of (70,80)mm
diameters were used in this work. The results show that after heating to (1000)c°
holding (90) minutes blast air cooling for given time and cold water quenched,
tempering at (400)c° for (4) hrs, still air cooling gave the best results in hardness
values with low retained austenite , And nearly the same results could be achieved
by oil quenching and the same tempering conditions.