Premature Wear Out of SAE 52100 Rings
Premature Wear Out of SAE 52100 Rings
(OP)
We are manufacturing spinning rings used in Textile Industry. They are made from SAE 52100 or equivalent grade of steel pipes. After machining they are heat treated (marquenching) to 62-63 HRc. Later they are polished using vibratory and centrifugal machines.
We have enclosed a pic which shows cross section of the ring and the traveller ("c" shaped small component) which runs on it at around 30 meter/sec speed. Usual life of the ring is around 2-3 years. There is no lubrication between ring & traveller which please note.
At times we have received complaints from out customers that the rings get worn out prematurely in say 2-6 months. We have found that most of these worn out rings have 62 HRc or higher hardness which is as per the requirement. The traveller that runs on rings have hardness of 55-57 HRc. What could be triggering the wear out ?
We have enclosed a pic which shows cross section of the ring and the traveller ("c" shaped small component) which runs on it at around 30 meter/sec speed. Usual life of the ring is around 2-3 years. There is no lubrication between ring & traveller which please note.
At times we have received complaints from out customers that the rings get worn out prematurely in say 2-6 months. We have found that most of these worn out rings have 62 HRc or higher hardness which is as per the requirement. The traveller that runs on rings have hardness of 55-57 HRc. What could be triggering the wear out ?





RE: Premature Wear Out of SAE 52100 Rings
I presume that you have ruled out any variations in the products that your customers run as being an issue?
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P.E. Metallurgy, Plymouth Tube
RE: Premature Wear Out of SAE 52100 Rings
RE: Premature Wear Out of SAE 52100 Rings
RE: Premature Wear Out of SAE 52100 Rings
We use 2nd grade tubes and hence I believe that there could be more impurities or other problems that you guys have mentioned. What can I do to ensure that the same doesn't happen again ?
RE: Premature Wear Out of SAE 52100 Rings
If the material is of lower quality for your service condition, the easy fix is to develop an engineering specification that details the material specification so that your procurement folks order the material you specify.
RE: Premature Wear Out of SAE 52100 Rings
If you can get a copy of ASTM A295 I believe it gives some limits for the depth of the decarburized layer.
RE: Premature Wear Out of SAE 52100 Rings
RE: Premature Wear Out of SAE 52100 Rings
Can you provide a definition of what you mean by a "worn out" ring? Is it a certain dimensional condition that the ring surface has eroded to?
RE: Premature Wear Out of SAE 52100 Rings
When I say worn out, I mean that the contact area that I mentioned above gets uneven and hence the small component that runs over the ring can't run smoothly anymore.
I hope I have explained it clearly.
RE: Premature Wear Out of SAE 52100 Rings
RE: Premature Wear Out of SAE 52100 Rings
I've enclosed a pic to show the abnormal wear. Hope it will clarify the matter a bit.
RE: Premature Wear Out of SAE 52100 Rings
Comparing the picture in the OP of a generic ring/follower and the picture of your own ring design in the last post, the one big difference I see is how much smaller the corner radius is of your ring rim where the traveler bears against it. The picture of the generic ring shows a cross-section with very generous radius at the inner rim corner where the traveler bears against it. With your ring design it seems possible that a high radial load applied to the traveler could produce local brinelling damage to the sharp radius ring rim edge, due to the minimal surface area at this contact. After the initial brinelling to the local surface, every time a traveler passes over that spot the damage would progressively get worse. So one suggestion I would offer is consider modifying the profile of your ring and travelers so that they have a much lower contact stress level. From what I can see, ring surface hardness is not the main problem you have.
RE: Premature Wear Out of SAE 52100 Rings
Firstly little about the images that I have attached in my previous post. The first image of cross section of Ring is a photograph used for marketing purpose it doesn't show the actual dimensions. The second pic was of actual ring that has faced the "brinelling / wear out".
To have a clearer idea I am attaching a dimensional drawing of the ring to understand that there is very small contact area between Ring & Traveller. Also you may note that we check the same on a 50X magnification projector to make sure that our product is as per the standard profile. So the deviation would be pretty small and wouldn't really make difference.
Now considering that its local Brinelling, what precautions can we take to make sure that it doesn't happen again in our future lots ?
RE: Premature Wear Out of SAE 52100 Rings
The only other thing I could suggest is making sure the metallurgy of your ring is what you specified. As I noted above, with the type of raw material you used for this part, there can be an issue with de-carburization in the outer surface layers. And from your picture of the ring, it looks possible that you might not have removed enough of the inner stock surface to fully remove the de-carburized layer.
RE: Premature Wear Out of SAE 52100 Rings
How much layer should be removed to De-carb the rings properly ?
RE: Premature Wear Out of SAE 52100 Rings
It is also possible that there is retained austenite in the microstructure. This could also lead to the premature failure that you described. An examination of the failed part should also allow you to determine if this is the source of the problem as well. Do the rings undergo a cryogenic treatment as part of the normal heat treating cycle?
Maui