ACID ETCHING 300 Series Stainless Steel

[Elephantine49er]

thread177-122890

I have performed Nital/Ammonium Persulfate acid etching on Carbon Steels to verify removal of Arc Burns per ASME B31.4 and B31.8, but have never applied this technique to Stainless. Are these solutions detrimental to Austenitic Stainless such as 304 and 316L or would this be an appropriate technique?

Any help would be great.

Thanks!

David.Blosser@kinetic-solutions-llc.com

http://www.kinetic-solutions-llc.com

 

[OGMetEngr]

ASTM A340 gives a few options for austenitic stainless steels. I'd take a look at that.

 

[EdStainless]

There are other etchants to use for that.

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[Elephantine49er]

ASTM A340
Quick View
Active,most current, complete document
Revision / Edition: 03A Chg: W/ REAP Date: 00/00/11
STANDARD TERMINOLOGY OF SYMBOLS AND DEFINITIONS RELATING TO MAGNETIC TESTING

Is this the document to which you were referring?

Not sure how it applies to etching. What am I missing here?

 

[Elephantine49er]

Which etchants would you recommend Mr. EdStainless?

Thank you.

David.Blosser@kinetic-solutions-llc.com

 

[OGMetEngr]

Whoops, meant to say ASTM E340.

 

[metengr]

There are various etchants to use for stainless steel, depending on the grade;

See below;

http://www.metallographic.com/Etchants/Stainless steel etchants.htm

http://books.google.com/books?id=Or...e&q=macroetchants for stainless steel&f=false

 

[EdStainless]

I typically start by looking at unetched samples.
Then as a first pass use 10% oxalic electro etch.
The need for other etchants then really depends on what phases you are looking for.
I have entire books on this subject.
Start with the ASM handbook and work from there.

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