Grinding Ball Center Hardness

- Sep 23, 2019-

High-chromium white cast iron grinding balls are also called high-chromium alloy cast balls and high-chromium steel balls, which are simply called high-chromium balls. At present, most of the domestic wear-resistant materials enterprises are mainly medium-frequency electric furnaces, which are smelted by reasonably matching high-quality scrap steel and chrome alloy materials; and micro-alloying and quenching of molten iron; The sand mold casting process; and then the high temperature quenching + tempering treatment to obtain a martensite matrix to achieve higher hardness and wear resistance.

In terms of chemical composition, there are dozens of different materials ranging from low chromium to high chromium. In order to standardize the industry standards, let people have a clear understanding of the chromium alloy casting ball from the rational, casting grinding ball GB/T17445-2009 national standards, low chromium chromium content of 1% -3%, hardness HRC ≥ 45; Alloy ball chromium content 4%-6%, hardness HRC≥47; medium chromium alloy ball chromium content 7%-10%, hardness HRC≥48; high chromium alloy ball chromium content ≥10%-14%, hardness HRC≥58; The special high chromium ball has a chromium content of more than 14% and a hardness of HRC ≥ 58.

 High chromium ball national standard requires hardness (HRC) must be ≥ 58 or more, falling ball impact fatigue life (number of times) ≥ 20000, impact value ak ≥ 3.5J / cm2, chromium content Cr ≥ 10.0%, breaking rate ≤ 0.5%, including The amount of carbon is between 1.8% and 3.3%, collectively referred to as high chromium balls.