北奔重卡传动部件7532轴承失效分析
Invalidation Analysis of 7532 Bearing Transmitting Motion Part in Beiben Heavy-duty Car
姚立华, 王飞腾, 钱裕生, 武玉平
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作者单位：(内蒙古第一机械制造(集团)有限公司 北方实业公司, 内蒙古 包头 014032)
中文关键字：轴承； 失效； 剥落； 划痕
英文关键字：bearing; invalidation; spalling; scarification
中文摘要：通过对轴承内、外套和滚子进行外观形貌检查、材质化学成分分析，以及金相、硬度检测等，确认失效主要原因是轴承外套心部的金相显微组织与过渡部位、表面部位的金相显微组织存在一定的差异，导致各部位的力学性能存在较大的变化。轴承外套组织的不均匀性和心部较低的硬度，在轴承滚子反复滚动接触应力的作用下，在轴承外套硬化过渡层产生疲劳裂纹，并与表面平行方向扩展，最后形成亚表面麻点、压碎剥落。
英文摘要：Through checking external pattern of internal-external bearing sleeve and roller, analyzing chemical composition, testing metallographic phase and hardness, the main reasons of invalidation were determined. The different metallurgical structures between the center of bearing's external sleeve and transition/surface induced to inconsistent mechanical properties in the sections. Because of inconsistent structures and lower hardness in the center, the fatigue crack was generated in hardened layer of external bearing sleeve. Subsurface pitting and spalling flake were formed with crack expansion along surface parallel direction.