ASTM AG48 Method A - Acceptance criteria 1

[Shivasankar2593]

Dear Friends,

Can anyone tell me what is the acceptance criteria for the test ASTM G48 Method A.

Thanks in advance.
Shivasankar
D.Manager - Quality Control

 

[SJones]

Which alloy?

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.

 

[Shivasankar2593]

Its a SA470 UNS32205 Round Rod

 

[SJones]

Typically, for a 24 hour exposure at 25 deg C:

- No pitting at 20x magnification (plus optional penetrant testing)
- Weight loss less than 1 gramme per square metre

ISO 17781

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.

 

[Shivasankar2593]

Thanks for your timely answer Mr.Jones.
Let me check and convey the results with you soon.
Thanks again for your time.

 

[EdStainless]

Sorry but not really.
G 48 has no criteria, it is a test method.
The temp reported in the lowest at which pitting occurs for the given alloy/solution/time.
What are you testing for?
Pitting resistance?
Intermetallics? This is a different test, A923.
While they look the same and are very similar they are not identical.
A923 requires a freshly ground surface, G48 can use any surface desired.
If this is a pitting test I would strongly suggest using method E, it is much more repeatable than A.
But don't expect exact result, not Table 2.
These are labs who do this work for a living and for 2205 they reported 20-40C.


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P.E. Metallurgy, consulting work welcomed

 

[SJones]

'@Ed,

For sure, G48 on its own has no acceptance criteria which probably prompted the question. Ever since duplex took off in the 80s, plenty of work on both the test parameters, and the acceptance criteria, for manufacturing quality control purposes has been carried out. I’ve quoted the current criteria from ISO 17781 which is drawing a lot of use from the oil & gas industry.

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.

 

[EdStainless]

There are temperatures listed in A923, but that is a different test.
These are often confused and I have rejected a lot of 2205 over the years for this reason.
I believe that the values listed (25C for 2205) are also specifically for welds.
Mill annealed bulk material had better be better than this.

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P.E. Metallurgy, consulting work welcomed

 

[SJones]

22 deg C for welds.

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.

 

[EdStainless]

Thanks for catching that Steve.

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P.E. Metallurgy, consulting work welcomed