feriite delta and electrolytic polishing ?

[Fred]

We have pb with the surface of some parts made in 316L after an electrolytic polishing. The microstrucutre examination reveals an large amount of ferrite delta and we wonder if it could explain the aspect of the surface (like a presence of a white layer)

 

[unclesyd]

What is the 316L material's environmental history?

 

[Fred]

I have not yet any information about its history. But we have carried out several tests of decontamination in nitric bath without result

 

[EdStainless]

What are the parts? Castings? Welded from sheet or plate?

And why is this a problem? Sure you will get some texture, but the surface will still be microscopicaly feartureless. Why are you using EP?

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm

 

[Fred]

We are talking about connecting parts manufacture from bars requiring a high property and the customer could see with a bad eye an irregular aspect.
The EP has also the function of increasing the corrosion resistance.

 

[EdStainless]

What is the mechanical polishing that they are given first?
Is this a surface condition issue, or does it go deeper?

= = = = = = = = = = = = = = = = = = = =
Corrosion, every where, all the time.
Manage it or it will manage you.

http://www.trent-tube.com/contact/Tech_Assist.cfm