Grinding steel balls
Balls subdivided into groupsby hardness:
1 - normal hardness of common purpose;
2 - hardened general purpose;
3 - high hardness for grinding ferrous metal ores;
4 - very high hardness for grinding nonferrous metal ores, cement, refractories.
| Section name | Production standard | HRC Hardness (HB), not less, for groups | ||||
| 1 | 2 | 3 | 4* | |||
| GOST 7524-89, DSTU 3499 | on the surface of the ball | at a depth of ½ radius of the ball | ||||
| 40 | 43 (401) | 49 (461) | 55 (534) | 55 (534) | 45 (415) | |
| 60 | ||||||
| 70 | ||||||
| 80 | 40 (352) | 42 (375) | 52 (495) | 52 (514) | ||
| 90 | – | – | ||||
| 100 | 52 (514) | 45 (415) | ||||
| 120 | 35 (302) | 38 (331) | 50 (477) | – | – | |
*Balls with a diameter of 80 mm, 100 mm very high hardness made of steel SH2L by TT 14788411-93-2009.
Chemical composition and hardness of the steel balls SH2L
| Mass fraction of elements,% | HRC Hardness (HB), not less, | |||||||
| C | Mn | Si | P | S | Cr | Ni | Cu | |
| not more | not more | |||||||
| 0,65 – 0,75 | 0,70 – 0,80 | 0,20 – 0,35 | 0,035 | 0,035 | 0,50 – 0,60 | 0,3 | 0,3 | on the surface of the ball 52(514); |
| at a depth of ½ radius of the ball 45(415) | ||||||||
Delivery of balls to the customer is carried out in bulk or packaged in big bags for 1 ton.