B91 consumables 1

[WE91]

SFA 5.28 for example says the following regarding ER90S-B91 "B7.18 ER90S-B91 [ER62S-B91] and E90C-B91 [E62C-B91] (9Cr-1Mo, Nb, and V modified). The B91 type filler
metal is a direct replacement to the B9 electrodes in previous editions. The B91 type filler metal is a 9% Cr-1% Mo type
modified with Nb and V to provide improved creep strength, and oxidation and corrosion resistance at elevated temperatures.
Due to the higher elevated temperature properties of this alloy, components that are now fabricated from stainless and
ferritic steels may be fabricated from a single alloy, eliminating problems associated with dissimilar welds.

Can anyone shed light or point me towards a reference that would explain, " eliminating problems associated with dissimilar welds," I would assume the microalloying additions play a role of course but can not find anything definitive.

Thank You

 

[EdStainless]

Go to EPRI and read the publicly available papers on 9Cr and 9-1 applications and failures.
Issues with differences in creep and aging properties of base metal and weld filler are numerous and have lead to many failures.

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P.E. Metallurgy, consulting work welcomed

 

[weldstan]

And there are more failures unaddreesed by EPRI.