夜夜躁狠狠躁夜躁2021_欧洲成人在线观看_中国少妇饥渴XXXXX_人妻巨大乳挤奶水HD免费看_视频二区在线播放_九九热精品在线视频

There are three basic forms of grinding wheel wear: abrasive wear, crushing wear and shedding wear.

(1) Abrasion wear. The abrasion wear is manifested as the formation of small edge surface on the grinding grain of the grinding wheel. In the grinding process, due to the mechanical friction of the hard point of the workpiece, high-temperature oxidation and diffusion, etc., the cutting edge of the grinding grain will produce wear passivation and passivation.

(2) Crushing and wear: In the grinding process, the abrasive particles undergo repeated and repeated hot and cold for many times, forming a great thermal stress on the surface of the abrasive particles, and finally the abrasive particles appear local crushing along a certain surface.

(3) Shedding and wear; During grinding, the strength of binder decreases with the increase of grinding temperature. When the grinding force increases beyond the strength of the binder, the whole abrasive particle falls off the grinding wheel, which is called shedding wear.

The grinding performance deteriorates as a result of grinding wheel wear, mainly in three forms: passivation type, shedding type (shape distortion) and plugging type.

When the grinding wheel is of high hardness, fine dressing and light grinding load, the passivation type is easy to appear. At this time, the machining table and although the quality is better, but the metal removal rate significantly decreased.

When the grinding wheel has low hardness, coarse dressing and heavy grinding load, it is easy to fall off. At this time, the sand profile distortion seriously affects the grinding surface quality and machining accuracy.

When grinding carbon steel, due to the chip softening under high grinding temperature, it is embedded in the gap of the grinding wheel to form embedded plugging; During grinding titanium alloy, the chip melts and sticks to the grinding particle due to the strong affinity between the chip and the grinding particle, forming an adhesive plugging. When the grinding wheel is blocked, the cutting ability is lost, grinding force and temperature increase sharply, and surface quality decreases obviously.