Usually people think that because diamond and iron group elements are chemically inert, grinding diamond wheel is not suitable for the gray cast iron work pieces. However, this case only occurs at the high temperature. For example, when grinding with a diamond wheel at a temperature of 650 ℃, the diamond will be oxidized in the air, and when at a temperature of 700 ℃ ~ 800 ℃, it will be graphitized. At low temperatures, the materials do react. So, as long as we select the appropriate working speed and wet grinding with sufficient grinding slurry, the diamond grinding wheel is certainly can be used for cast iron, which has been proven in production practice. When using wet grinding, grinding ratio (9600)of diamond grinding wheel for grinding gray cast iron is much higher than that (2700) of CBN grinding wheel.
It is also generally believed that CBN grinding wheel is not suitable for low-carbon steel for soft materials, because the wear debris is easy to block the grinding wheel. But the study suggests that vitrified CBN grinding wheel can increase the line speed with fine debris, then we can remove debris by high pressure spraying liquid, and supply adequate grinding fluid and other measures to prevent wheel block. Thus, CBN grinding wheel can grinding the soft material low-carbon steel (hardness higher than 30HRC). However, CBN grinding wheel is not valid for any material. Usually it is not suitable for grinding carbide and carbide-steel assembly, at this time, diamond grinding wheel perform better.