五、质量保证经过磨削的表面可具有出色的光洁度(粗糙度微英时AA读数很低)、精确的尺寸且加工方法非常经济。但同一表面可能掩盖了某些区域的显微裂纹,也可能因残余应力高而产生塑性变形。图28所示为高强度钢制造的传动轴。这根传动轴使用后不久即出现故障。这说明了:(1)表面关键区域工艺选择的必要性,(2) Fifth, the quality assurance After grinding the surface can have excellent finish (roughness micro-British AA readings are low), the precise size and processing methods are very economical. However, the same surface may mask some areas of the micro-cracks, but also may be due to residual stress and plastic deformation. Figure 28 shows the drive shaft made of high strength steel. The drive shaft failed soon after its use. This shows: (1) the necessity of the process selection of the key surface area, (2)