The method of grinding steel balls with a grinding whee […]
The method of grinding steel balls with a grinding wheel in a ball mill after heat treatment is called hard grinding. Its function is to eliminate soft grinding (or smooth grinding) defects and remove surface oxidation, decarburization, deformation and troostite structure defects generated during heat treatment. Further improve the accuracy and surface quality.
During or after the hard grinding process of the steel ball, the surface defects should be visually inspected, and the burns should be inspected after cold pickling. The burns can generally be divided into secondary tempering burns and secondary Stainless Steel Ball quenching burns. The secondary tempering burns appear black after cold pickling. After the secondary quenching burn is cold pickled, the middle is gray martensite, and the surrounding is black troostite. There are linear burns, spot burns and bipolar burns (large ball burns).
Causes of linear burns:
1. The groove of the cast iron disc or the grinding wheel is too deep, which affects the flexibility of the steel ball rotation;
2. The cast iron disc or grinding wheel working surface is not parallel or the groove depth is inconsistent, causing the friction phenomenon of the steel ball on the top of the steel ball;
3. The grooves of the cast iron disc or the grinding wheel do not match;
4. The junction of the distributor and the cast iron plate does not match;
5. The bell mouth at the entrance of the cast iron plate is too wide, so that the steel ball touches the edge of the grinding wheel groove;
6. Improper adjustment of the slope of the ball groove makes the steel ball flow too fast or too slow;
7. The grinding wheel is blocked by falling particles (blocks), which makes the in and out of the ball not smooth;
8. The suction angle of the ball-coating blade is too flat or worn into a concave shape, and ball-coupling is not smooth;
9. Improper application of work pressure.