Chemical analysis of casting grinding ball

Casting grinding steel balls can be divided into high chrome balls, medium-chrome balls and low chrome balls. The performances of grinding steel balls may vary in a wide range for different raw materials. Now, let’s make a brief chemical analysis of casting grinding steel balls
1. High chrome steel ball: 12% of Chrome and Ge, the main lattice type of eutectic carbides is （Fe、Cr）＞Cэ
2. Medium chrome grinding ball, the chrome content is about 5%-10%, the main lattice type of eutectic carbides is （Fe、Cr）＞Cэ
3. low chrome grinding media: the chrome content is less than 5%, and the main lattice type of the eutectic carbides is （Fe、Cr）＞Cэ.
What’s the functions of different alloy compositions in cast steel ball?
1. Carbon content: if the content is high, grinding ball will have high wear-resistant performance but high breakage rate, however, if carbon content is low, the toughness is high and the ball won’t be easily break but not wear-resisting and the hardness is low. Generally, the carbon content in low chrome grinding ball is 2.2％～3.6％, while in high chrome is 1.7％～3.2％.
2. Mn content: Mn is a kind of austenitic stabilizer, which can improve the steel hardness and improve wear resistance. The Mn content in low chrome steel ball is 0.5％～1.5％, an in high chrome is 0.5％～2.5％
3. Cr content: Cr is a hardening agent which ensures the hardening of the micro-structures. In this point it greatly improves the wear resistance of grinding ball.
4. Mo content: refine the crystal structure, improve the impact strength of micro-structure, and enhance grinding ball toughness. In low chromium ball, the Mo content is about 1%, and in high chrome ball the content is 3%
5. Cu content: after heat treatment, part of copper will be precipitated in solid solution form, which improve the tensile strength, yield strength and hardness of grinding ball and improve the flow of molten metal.
6. Si & Al: in smelting process, these chemical components can deoxidize metallic oxides.