内圈异常二次磷化对铁路轴承性能的影响

Effect of Abnormal Secondary Phosphating of Inner Rings on Performances of Railway Bearings

针对某铁路轴箱用双列圆锥滚子轴承内圈异常二次磷化后轴承运行过程中出现严重发热故障的问题,进行相关试验以进一步研究内圈二次磷化导致轴承失效的机理。试验结果表明:相较于正常一次磷化,内圈二次磷化的磷化膜厚度更大,磷化腐蚀层更深,膜层附着力较弱,更易磨损脱落;二次磷化轴承经跑合试验后,内圈磷化膜短期内出现大量磨损,导致轴向游隙异常增大,进而使轴承出现比较严重的偏载现象,同时润滑脂润滑性能下降,内部摩擦发热增大,导致轴承发生严重发热故障。

In response to the problem of serious heat generation fault during operation of double row tapered roller bearings for a railway axle box after abnormal secondary phosphating of inner rings,the relevant tests are conducted to further study the mechanism of bearing failure caused by secondary phosphating of inner rings.The test results show that compared with normal primary phosphating,the thickness of phosphating films is thicker after secondary phosphating of inner rings,the phosphating corrosion layers are deeper,the adhesion of film layers is weaker,and the films are more prone to wear and fall off;after running-in test of the bearings with secondary phosphating of inner rings,the films on inner rings appear a lot of wear in a short period of time,resulting in abnormal increase of axial clearance,which leads to a relatively serious partial load phenomenon of the bearings.At the same time,the lubrication performances of grease decrease,and the internal friction heat generation increases,resulting in serious heat generation fault of the bearings.