Many enterprises in the process of the use of steel balls will appear in the case of ball, ball mill ball in the use of 2000 hours after the detection of loss of circle is greater than seven percent. (out of roundness = (maximum diameter - minimum diameter, average diameter) * 100%)
Reason of steel ball missing circle:
1, the chemical composition of unqualified steel ball; that is, the use of raw materials components are not up to the standard, the purchase of small steel mills.
2, heat treatment process is not correct, the stress has not been eliminated, residual austenite is too high, (general residual 15% - 30%) in the use of austenitic heat transformation of martensite, volume expansion, an increase of internal force, 9-10 hours after the phenomenon is serious;
3, impurities in the steel; steel inclusions too much impact on the quality of the steel ball and the use of.
4, raw material (raw material) hardness, temperature, moisture, the speed of the mill, the structure of the lining board, gradation and so on have influence; this aspect has certain influence, but not very big.
5, grinding process conditions and mill operating conditions (the metal into the grinding of the metal corrosion and abrasive, abrasive, the hardness of the material, the size of the grinding material, the fineness of the finished product)
6 steel ball production process is not perfect, making the steel ball in the heat treatment process has not been a full range of quenching and tempering, the hardness of the steel ball is high, the other side of the phenomenon of low hardness, commonly referred to as the "Yin and yang". Hardness is not uniform, making the steel ball in the process of wear and tear is not the same, high hardness wear slow, low hardness and wear fast, resulting in the phenomenon of steel ball out of circle.