317L Allowable Stresses above 850F

[AMatthews]

Are there any allowable stress values available to use 317L piping above 850F?

 

[metengr]

No, I don't believe there are values for this material at elevated service temperature (see ASME B&PV Code, Section II). The concern with using Type 317/317L stainless above 650 deg F is the formation of sigma phase that will result in poor corrosion resistance and toughness.

 

[ijzer]

ASME IID have stresses for 317 (without L) up to 1500 Deg.F

 

[EdStainless]

I can think of two reasons, but I don't actaully know.
The carbon is an austenite stablizer, so teh straight grade alloy is less likely to form sigma. Of course the higher carbon also will result in higher creep strength. The higher strength won't help if the material is brittle though.......

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