The first stage is the shedding and cutting stage. In this constant pressure honing, at the beginning, due to the roughness of the hole wall, the contact area between the oilstone and the hole wall is very small, and the contact pressure is large, and the protruding part of the hole wall is quickly ground away. However, due to the high contact pressure on the surface of the whetstone and the abrasion of the whetstone binder by the chips, the bonding strength between the abrasive particles and the binder decreases. Therefore, some abrasive particles fall off by themselves under the action of the cutting pressure, and the whetstone surface is exposed. Abrasive particles, this is the self-sharpening of the oil stone.
The second stage is the crushing and cutting stage. With the progress of honing, the surface of the hole becomes brighter and brighter, and the contact area with the oil stone becomes larger and larger, the contact pressure per unit area decreases, and the cutting efficiency decreases. At the same time, the chips cut off are small and fine, and the wear of these chips on the binder is also very small. Therefore, the abrasive grains of the whetstone fall off very little. At this time, the grinding is not performed by new abrasive grains, but by the sharp surface of the abrasive grains. Therefore, the load on the tip of the abrasive grains is very large, and the abrasive grains are easily broken and shattered to form new cutting edges.
The third stage is the clogging cutting stage. When the honing continues, the contact area between the whetstone and the hole surface becomes larger and larger, and the extremely fine chips accumulated between the whetstone and the hole wall are not easy to be removed, causing the whetstone to be blocked and become very smooth. Therefore, the cutting ability of the oilstone is extremely low, which is equivalent to polishing. If honing is continued, when the whetstone is seriously blocked and the cohesive blockage occurs, the whetstone completely loses its cutting ability and generates serious heat, and the accuracy and surface roughness of the hole will be affected. At this point, honing should be terminated as soon as possible.