The size of steel balls is up to 125MM in diameter in mass production, because of the presence of tensile stress in the center of the steel ball during the hot rolling process, it is not recommended to produce oversized steel balls (Dia.>125mm). The production efficiency of skew rolling process is extremely high, but the quality is not as good as pneumatic hammer forging process or finishing by roller after forging process.

Chromium alloy is the main component of casting steel ball. The density of casting ball is lower than forging steel ball, the resistance of oxidation, high-sulfur, diesel fuel and seawater are poor, and its breaking rate is much higher than other steel balls by different process. According to the level of chromium content, casting ball can be divided into the following categories:

① Chromium content of 1% -3%, hardness HRC ≥45. The wear-resistant steel ball under this spec is called a low-chromium alloy casting ball. Low-chromium casting balls are produced by process as IF induction furnace melting, die casting or sand casting. Its performance is suitable for metallurgical mines, slag treatment and other industries which require low grinding accuracy and low wear consumption.
② Chromium content of 4% -6%, hardness HRC ≥ 47. This wear-resistant steel ball called multicomponent-alloy casting ball, it is better than the strength and wear resistance of low-chromium casting steel ball.
③ Chromium content of 7% -10%, hardness HRC ≥ 50, called medium-chromium alloy casting ball, the main performances are better than the multicomponent-alloy casting ball.
④ Chromium content ≥ 10% -14%, hardness HRC ≥ 58, high chrome alloy casting ball is the main kind of wear-resistant ball with high rate of usage in the cement industry. It had been used in a wide range of applications, however, due to its low performance-price ratio, to be gradually replacing by hot-rolling and forging steel balls in the market.
⑤ Chromium content of more than 14%, hardness HRC ≥ 58. The special high-chromium casting steel ball is suitable for the industries with fine grinding, large consumption, of course, its price is also high, the cost-effective is lower than normal high-chromium casting ball.
Due to the performance-price ratio of casting steel ball is not good, the market share has dropped in recent years.
For further details of the materials and production equipment for hot rolling steel balls and forging steel ball, please download our manual.