Super Duplex Forging Not meeting ASME But ASTM properties

[ankush85]

Hello Guys
I need some guidance regarding Super Duplex Forging SA-182 F53 (UNS32750).

We are in process to procure forging to build ASME U-Stamp, High Pressure Filter Vessel. However, we are having issues with this material not meeting Tensile (116 KSI) and Yield (80 Ksi) as required by ASME SA-182 Ed.2019 specification. Forging are almost 9-10" thick and 24 " diameter.

Our supplier is getting Tensile 113 KSi and Yield 77 Ksi. These strength values are acceptable per ASTM A-182 but not per ASME SA-182. Our Supplier has tried re-heat and retest but still no improvement.

Undoubtedly, for ASME U-stamp vessel, all pressure boundary items has to meet "SA" spec.

Now question is;
1. Is there any exception or way we can use this material(ASTM A-182 F53) and still U-Stamp the vessel?
2. Does anyone had an experience with this material and can advise some inputs for forging process itself which can result the required mechanical properties?

Thanks

 

[EdStainless]

When did the two version of 182 get different properties? Is this a function of size?
I don't recall any cases where the ASTM and ASME specs had different properties unless it was a delayed revision issue.
Is A923 required on these? You would need to quench into chilled water from the anneal in order to suppress intermetallic formation.

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P.E. Metallurgy, consulting work welcomed

 

[ankush85]

Hi Ed,
Edition 2019 for both ASME and ASTM are slightly different for forgings. Reduced tensile & Yield strength as the forging thickness increases had been removed from ASME SA-182 Ed.2019 but ASTM A-182 still allowed these reduced strengths.

Yes, A923 is required for these forging. Supplier is required to do Tensile, Charpy Impact, Corrosion and Ferrite Content test and did not see any issue but mechanical strength.

The real issue that we are facing is; how to accept this material while meeting ASME criteria and still U-stamp the vessel.

 

[ankush85]

One more item where would like to have some direction from community.

For the same titled project, Customer advised to try 654SMO or 254SMO material. I would like to re-design the entire pressure vessel with this material scheme, however, these Forging materials are not mentioned in ASME SA-182 specification and i am not sure how to go about considering allowable stress values at design temperature of 600 deg F which are available in Table 1A for ASME SEC II Part D for ASME listed materials, but not for these materials.


Please advise your inputs.
Thanks

 

[EdStainless]

It is more likely that the ASME is based on an old ASTM that didn't have the reduced strength for heavy sections. And that ASTM has updated and ASME has not yet.

Are any of the 6%Mo superaustenitics listed? (AL-6XN, 1925hMO, 25-6HN)
I am not sure if there is a different forge spec that covers these or not, that is what you need to look for.

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P.E. Metallurgy, consulting work welcomed