Bearing the workpiece surface has direct waveform We will ground workpiece axis of vertical line cut a cross-sectional and amplification, can see its peripheral similar to sine wave. Turns its center along the axis without translation, the perimeter of the sine wave trajectory is corrugated cylinder, also called the polygon. The reasons of the direct wave is the movement of the grinding wheel relative to the workpiece or the pressure of the grinding wheel for grinding vibration caused by the periodical change between ACTS. This may be a forced vibration, vibration may also be a self-excited vibration, thus the workpiece on the direct wave and frequency are often more than one.

Traces of the bearing straight waveforms specific reason is: 1. The grinding wheel spindle clearance is too large; 2. Grinding wheel hardness is too high; 3. The grinding wheel static balance is bad or the grinding wheel dull; 4. The rotating speed is too high; 5. The horizontal Qi knife is too large; 6. Grinding wheel spindle bearing wear, fit clearance is too large, produce radial runout; 7. Grinding wheel pressure institution or workbench "crawling" and so on.
Burn mark surface rendering Surface often in the process of grinding burn, burns has several types, a burn is along the direction of grinding wheel processing, black spots; 2 it is to show lines or intermittent lines.
Surface in the process of grinding burns, induces has the following several reasons: 1. The granularity of grinding wheel is too hard or too finely organized; 2. The feeding is too big, cutting fluid supply, poor heat dissipation condition; 3. The rotating speed is too low, grinding wheel rotation speed too fast; 4. The grinding wheel pendulum is too big, due to the grinding depth constantly change and burns; 5. Grinding wheel dressing time dressing is bad; 6. Sharp diamond grinding wheel dressing is bad; 7. Coarse grinding workpiece burn too deep, fine grinding allowance is too small, no wear off; 8. The workpiece clamping force or insufficient suction, under the effect of grinding force, the workpiece is stalling phenomenon, etc. So how to know whether to burn in the process of grinding workpiece surface service? It shall be by pickling can be detected on a regular basis. Acid treatment of workpiece, when the surface wet, immediately under the astigmatism lamp visual inspection, surface normal uniform dark gray. Points, so software rendering clouds form dark flecks, and the perimeter and the whole; If the decarburization, presents a gray or black spots; If the grinding cracks, the crack is cracked, so burn, one is the surface along the direction of grinding wheel processing present diablo splash block, 2 it is to present lines or discontinuous line shape. Such as appeared in the process of grinding burn phenomenon above, must be timely analysis of the reason, take effective measures to solve, put an end to mass burn.