轴承外圈端面磁痕分析

Magnetic Marks Analysis on End Surface of Bearing Outer Ring

磁粉探伤工序发现轴承外圈端面存在大量的短磁痕,采用低倍检查、金相检验、断口扫描电镜观察等方法对磁痕缺陷产生的原因进行了分析及确认。结果表明:磁痕处存在孔洞缺陷,经检测同批次原材料棒料试样,发现了孔洞缺陷;该孔洞不同于过烧所致的孔洞,依据孔洞形貌特点,应为原材料显微孔隙。因此原材料显微孔隙导致了磁痕的形成。

A lot of short magnetic marks on the end surface of the bearing outer ring are found by magnetic powder inspection process. The causes of magnetic mark defects are analyzed and confirmed by means of low magnification examination, metallographic examination and fracture scanning electron microscope ob- servation etc. The results show that there are the hole defects in the magnetic mark, and the hole defect is detected by the same batch of raw nmterial. The hole is different from that caused by over sintering, and it should be the microscopic pore of the raw material according to the pore morphology. Therefore, the micro pores of raw materials lead to the formation of magnetic marks.