Difference between F55 and UNS 32760

[cnergy13]

Hi,
We have an on-going projects which requires valves to be F55. Our vendor offered UNS32760 which is not accepted. What is the difference between F55 (forged material) and UNS32760(Forged bar)?

Thanks

 

[EdStainless]

F55 links to a specification, the UNS number can be attached to many different specifications.
What spec is your document requiring?
It is the product spec that matters most, not what you call the grade (you may be wrong).

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P.E. Metallurgy, Plymouth Tube

 

[cnergy13]

Thank you EdStainless,
We have received an offer from vendor showing UNS32760 Super Duplex body, whilst our client datasheet shows ASTM A182F55.

 

[DekDee]

cnergy,
ASTM A182 F55 is UNS 32760
Why was it not accepted ?
Regards,
DD

 

[cnergy13]

DD, it was not accepted since UNS32760 was forged bar stock while F55 according to them is forged material.
I re-read your comments, so F55 is equivalent to UNS32760? Is there a good reference where we can refer to our client as back-up? Thanks,cnergy13

 

[EdStainless]

No, if UNS 32760 (by the way, a UNS is just a chemistry, with not restrictions on the manufacturing methods) is made to the requirements of A182, then it meets your spec.
F55 is simply an alternate name that was given to the alloy and has no meaning outside of A182.

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P.E. Metallurgy, Plymouth Tube

 

[DekDee]

cnergy,
It is not equivalent - F55 is UNS 32670
ASME IX 2015 Page 95 (second line from the bottom)
ASTM A182 Table 2 Page 11 (third line from top)
Regards,
DD

 

[SJones]

The issue appears to be the specific product form rather than any grade designation. A182 is clear on where bar can and cannot be used. If there is no additional specification modifying such use, then the resolution is also clear.

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/pub/8/83b/b04

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