Passivation of inconel springs?

[mjurek]

Is there any purpose to passivating inconel 718 springs? The springs are used in an aerospace application, therefore the corrosion resistance requirements are high.
Would electropolishing be a better option?

 

[israelkk]

This alloy is used for high temp application for upto 1300F. I do not see how passivation is needed. There is also no mention of this alloy in QQ-P-35.

 

[TVP]

In general, springs that have been formed out of Alloy 718 are not cleaned after the aging heat treatment. Do you have any specific customer requirements (Boeing, NASA, etc.) that have been specified regarding surface contamination, corrosion, etc.? One reference to the above is the Special Metals publication "Fabricating", available here:

http://www.specialmetals.com/documents/fabricating.pdf