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Rusting pins of racks for retractable roof

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ABA102

Structural
Mar 3, 2017
59
Hi,

May I ask your help for your assessment on rusting stainless steel pins of retractable roof.
Rusts were already removed but keep on showing up. Photo attached on current appearance.
Very high humidity in our environment has a great factor for this rusting but may I your expertise on how to deal w/ it.
Is there any problem on the material itself?

Regards

 
 https://files.engineering.com/getfile.aspx?folder=f518f304-5341-443a-bba3-e9924d25668f&file=rusting_pins.jpg
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"Stainless Steel" is usually a generic reference to any of dozens of alloys, some of which rust. Corrosion can be exaggerated by contact with carbon steel which contaminates the surface.
 
@3DDave

You may be correct. Actually the pinion gear travelling along the rack of pins is not stainless steel but painted steel only.
There are even group of pins along the track look like having burn mark, can it be that the chromium coating is removed?
 
Stainless steels do not have a chromium coating so it cannot be removed.

Find out what the specification for the pins was and what was actually supplied.
 
Do you have isolation between the carbon steel and what you're calling stainless?
 
I think 3DDave hit on it - transfer from the carbon steel that came in contact with the stainless. Has there been any section loss to the stainless pins or loss to the pinion gear that would sacrifice function or capacity? If not, then it would seem to be an non-issue, unless the increase in friction has become a problem functionally.
 
Hi gents,

Thank you for your contribution to this topic.

@GGedge
I was wrong buy telling that chromium coating.
After removing rust spots, some pins appear to have pitting corrosion, as shown on attached photo.

@Rabbit12
There is none. Actually I attached a photo in here for additional clarification.

@HotRod10
Yes, carbon steel pinion gear can be the main reason of rust spots and burn like appearance of the pins.

 
 https://files.engineering.com/getfile.aspx?folder=e6e55750-695e-4f72-81dd-d2c0dfdb450c&file=IMG_7289.JPG
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