What Is The Hardness Of High Chromium Grinding Media Balls

Release time：2021-10-12

The as-cast hardness of thick-walled parts can not be too high, which is 50-55HRC, but the thin-walled parts are better.  There is to add a certain amount of nickel and molybdenum, and then the silicon content can not be too high, these are influencing factors.  It should be possible to increase the hardness of cast to about 55HRC.  Only the composition adjustment in the as-cast cooling to achieve the transformation of austenite to martensite can improve the hardness.  Because its carbide hardness is also very high.

There are many ways to improve the hardness of high chromium cast iron, the composition control has a great influence on the hardness, improving the martensite transformation point is a good way, adding mo and vanadium to the alloy is beneficial to improve the hardness, if no heat treatment, reduce the chromium content is the correct choice.  It is difficult to convert carbides from austenite to martensite unless carbides are precipitated after heat treatment and the austenite is unstable.  In fact, if the high hardness of cast high chromium cast iron is achieved, the number and type of carbide is very key, generally Cr7C3 is good.  The hardness of carbide is actually higher than martensite, and the as-cast hardness is actually increased by carbide.