1) High Through Hardness: B2 balls show through hardness from surface to centre with 60HRC;
2) High Impact Test: The impact toughness is higher than 12 J/cm2;
3) Low Broken Rate: The microstructure consist of martensite near the surface. The microstructure at the centre consist of martensite and retained austenite;
4) Wear-resistance: Our grinding balls show a better wear resistance than others with 50-700 g/ton.
1. Feature:
1) As our test report of Mintek, the hardness of the 25mm-100mm Balls is consistent from surface to centre. The hardness of the 110mm-140mm Balls is consistent and decreases slightly from surface to centre.
Basically the hardness influences the toughness and the abrasion resistance of the grinding ball. The higher the hardness, the higher the abrasion resistance.
2) All our tested balls passed the drop test without any signs of spalling for 12000 drops.
3) The microstructure consist of martensite near the surface. The microstructure at the centre consist of martensite and retained austenite.
4) Even Wear-resistance: Our grinding balls show a better wear resistance than others with 50-700 g/ton.
2. Chemical Composition
B2 balls are high carbon-chromium steel balls.
| Brand | Material | C | Mn | Si | Cr | S | P |
| TITLE-1 | B2 (75MnCr) | 0.72-0.85 | 0.70-1.20 | 0.17-0.37 | 0.42-0.85 | ≤0.030 | ≤0.030 |
3. Hardness from Surface to Centre of B2 Balls
B2 balls show through hardness from surface to centre with 60HRC. 120mm ball hardness is consistent and decreases slightly from surface to centre.
4. Metallography
The microstructure of our balls consist of martensite near the surface. Their microstructure at the centre consist of martensite and retained austenite.
Below is micrograph of 120mm Ball taken (a) at the surface showing martensite (M) and (b) at the centre showing martensite (M) and retained austenite (RA).
5. Drop Test
All our tested grinding balls passed the drop test without any signs of spalling.
The drop test was performed on three balls from each to evaluate the impactive wear resistance. The test consists of dropping a ball from a height of 10 metres onto 300mm diameter hardened high chromium white cast iron balls. If the ball reaches 12000 drops, it has passed the drop test and is then classified as having adequate impact resistance for industrial application.
6. Wear Resistance
Our grinding balls show a better wear resistance than others.
Tested balls from each batch of the supplied grinding balls was tested in an experimental ball mill. The grinding balls were individually weighed in preparation for testing in an experimental ball mill of dimensions 600mm diameter x 600mm length. The material charged in the mill consisted of copper-nickel ore (<40mm) supplied by the client. Below is photograph and test result.
