Duplex SS ASTM 923-C vs. EN 3651-2

[DBreyer]

Hello all,

we are currently working on a new specification for Duplex SS (2205) for our site in Germany.
API 938-C recommends that base metal and welds are tested to ASTM 923 Method B or C (C is the corrosion test with ferric chloride solution).
According to German regulations VdTÜV 418 the EN ISO 3651-2 Test C (sulfuric Acid and ferric sulfate) is mandatory.

The Tests use diffeent solutions and have different acceptnace criteria (cracking vs. mass loss), nevertheless both try to identify if intermetallic phases are present.

As we would rather not specify 2 corrosion tests the question is if there is experience with only using the EN ISO test to determine corrosion resistance?
do you know of a study to compare results?

Thank you for your help!

Daniel Breyer
Inspection Engineer

http://lnkd.in/dFcQA-w

 

[EdStainless]

Isn't method B the low temp impact?
If so then it works well also, and is much easier to conduct and repeat than the corrosion test.
There is a direct ISO version of A923, so I can't believe that they are asking for a a different test.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy

 

[DBreyer]

Edstainless, thank you for the hint about an iso standard.
I wasn't aware of Iso 17781. It is also introduced as a german DIN standard.
This might make the whole spec easier as we don't have to reference american standards.

There is also a new version of the VdTÜV standard. I'll have to check if it references the new iso standard.

Regarding impact testing. For some cases itis the easier options (and we'll leave the option to do that) but for thicker sections it sometimes won't identify midwall intermetallics and for some weld geometries (e.g. tube to tubesheet) impact testing isn't practical.


Daniel Breyer
Inspection Engineer

http://lnkd.in/dFcQA-w

 

[SJones]

https://www.iogp-jip33.org/product/S-563v18-12.pdf

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.