产品失效分析报告英文版

N1008TN6 产品失效分析

从返回的文件数据来看，从 2019年 10月至 2019年 6月间共失效轴承 156起，失效 位置在 1、主轴后 36起； 2、第五齿轮 120 起；失效里程数不详。

从返回图片上的轴承的来看，失效的现象为：（外圈图片 1 张，内圈图片 1 张，滚珠 图片 2 张）

1 、

2 、 外圈滚道部分剥落，剥落位置偏端面一侧，滚道面未见色变； 内圈整体剥落， 已

看不见轴承原始加工表面，整个滚道面呈深坑状剥落痕

迹；

3 、 滚珠表面出现点蚀剥落现象，照片 1 中间一粒滚珠上有点片状剥落，照片 2 有五粒滚珠（安装位置为第五齿轮）尾端呈片区域状剥落，且从照片上可见滚珠来 看，

每粒滚珠上都有 2 条亮线；

单从返回照片上的轴承来看，该套轴承失效形式为疲劳剥落，产生失效的可能原因有：

1 、 轴承承受了较大的偏载，产生偏载的原因可能是安装倾斜或者是轴在承受 载荷时刚

度过小，产生弯曲，出现偏载；

2 、

3 、 轴承运行时长期受到过大的载荷，造成轴承疲劳失效； 轴承加工时热处理硬度 达不

到要求，硬度偏低、硬度值差偏大、零件表面

有脱贫碳现象；

4 、

5 、 零件有滚道烧伤现象 内圈滚道边有毛刺（留边）或者异物进入

最终结论需要对失效件进行热处理硬度、金相组织及材料成分检测，同时也需要对轴 承总的使用情况，失效里程进行综合分析才能确定是何原因造成。

Mahindra N1008TN6 Product Failure Analysis From the file data back to see,there are 156pcs failure bearings from October 2019 to June 2019. Failure position is as following: 1, 36pcs on the back of principal axis. 2, 120pcs on the fifth gear; Failure mileage is unknown.

As per failure bearing graph ,we can see the failure phenomenon as follows. 1 Outer ring raceway part flake, spalling position on one side, raceway partial end face has no color change. 2 Inner circle overall peeling off, already can't see the original bearing processing surface, the whole raceway surface shows pit type and flaking trace.

3 Ball surface appeared spalling and pitting phenomena, a grain ball has a little flake on the photo1. In the photo 2 , the end of five ball has (installation location for the fifth gear) exfoliation phenomenon, from the ball in the photo which is visible , we can see that each grain on the ball have two bright line article. Just from the bearing back in the picture, we can see that the failure way of this set of bearing is fatigue spalling. the possible cause of the failure is as following. 1 Bearing endure the larger partial load, the reason producing slanting load may be installed or axis tilt in small loads , causing bending, appear slanting load.

2 Bearing operation for a long time under big load, cause bearing fatigue failure. 3 Hardness short of asks when bearing is in heat treatment processing, low hardness hardness deviation value is too large, parts surface is out of poverty carbon . 4 Parts have raceway burns phenomenon

5 Inner ring raceway has a burr or foreign body in.

Final conclusion is that we need heat treatment of the failure parts, metallurgical structure and hardness material component testing, but also need comprehensively analysis the general use of bearing and failure mileage, to determine what causes.