Grinding steel balls can generally be divided into ball-shaped ball-grinding balls, forged steel balls, and cast steel balls during the production process. However, the current use of nodular cast iron balls is extremely small, and the use of cast balls and forgings in grinding balls is more common.
Grinding steel balls are heated by direct high temperature and then forged by air hammers. After simple heat treatment, the content of chromium is 0.1% to 0.5%, carbon content is less than 1.0%, and after high temperature forging, The surface hardness (HRC) can reach ≥ 56 or more, but due to poor material harden ability, hardened layer is only about 15mm,Therefore, the hardness of the core is generally only 30 degrees, and the greater the ball diameter, the worse the harden ability. Therefore, forged steel balls are quenched under normal conditions.
As for the abrasion resistance of the grinding steel balls, the high chromium balls quenched and tempered (HRC ≥ 60) have higher hardness and more than 2.5 times the wear resistance of forged steel balls. By comparison, the obvious advantages of a cast ball compared to a forged ball can be seen.
With the pace of mining, wear-resistant steel ball also needs further follow-up, ore crushing is increasingly demanding for wear-resistant steel ball. The domestic wear-resistant steel ball has better quality and more technical guarantees, so that it can win the competition with foreign mining machinery manufacturers. Thus prospering the country's mining industry, the grinding steel ball manufacturers have a better development.
Grinding steel ball in the process of selection will be effective according to the size of the ball mill, ore hardness, the ball of the ball mill, ball mill hardness (mass), ball mill speed and other factors to determine.