Yield stress of 9 chrome at 1375 deg F

[JG MechEng]

I have been asked by a client to rerate heater tubes to 1375 deg F and 890psi. Spent a fair amount of time trying to find yield strength data for 9 chrome at that elevated temperature. Also, API 530 larson miller parameter tables stop at 1300 deg F. Looking for some guidance on locating material data for the material to see if it’s even possible to make work. I do not want to get into a code discussion, this is not a code state and the client is willing to accept those risks.

 

[XL83NL]

You might see if it's documented somewhere in ASME STP-NU-018 - Creep Fatigue Data & Procedures for Gr 91 and Hastelloy XR (Ive looked in ASME STP PT 087 but wasn't able to find it there).

Huub
- You never get what you expect, you only get what you inspect.

 

[EdStainless]

Straight 9Cr or 91?
I have pages of data on 2 1/2Cr and on 409/410, but almost nothing on 9Cr.
You might try looking at EPRI guides as well.

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P.E. Metallurgy, consulting work welcomed

 

[JG MechEng]

Strait 9Cr

I spoke with a buddy of mine that is a metallurgist and another one from a separate client..between them two and the responses I’m getting here…sounds like a no no!

Thanks to all for the comments!

 

[blacksmith37]

Vry close to lower critical; sounds like a bad idea.

 

[WKTaylor]

JG... FYI ... when presenting a question like this...

Exactly what material spec was this alloy made per? The spec will define the entire chemistry and processing and provide clarity as to the specific material in question. IF any thing, what is the material UNS???

What is the environment of the exposure??? Air? Combustion-products? Inert gas? Vacuum? Plasma?

Regards, Wil Taylor
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