A182-F22 welding with impact requirement for -100F

By Arash486 Date 02-17-2016 22:52

I need to qualify a WPS for fabrication and WPS for F22 to F22 that needs to meet 20/15 ft.lbs CVN @ -100F and also 75ksi YS. None of -B3 filler metals meet 75 KSI yield after 1175F PWHT and also none of low alloy filler metals that meet NACE requirement of Nickel content of less than 1% can meet impact requirement at -100F. There is an option to use 625 but in myexperience it was really hard to meet 75 ksi yield strength. I will appreciate if any advise. Thanks.

By js55

Date 02-18-2016 16:32

75 ksi yield with impacts at -100 and they spec Grade 22?
Good lord.
625 should actually get you the properties you want but make sure you get actual testing certs to prove the chemistry.
Your problem is going to be twofold.
1) Dilution. You will have a high ductile to brittle transition from the bainitic allow diluting into the weld metal.
and
2)It will be worse if you have to do HAZ impacts.

By Arash486 Date 02-18-2016 20:12

Thank you Js55. actually it is one my of concerns too that what about the nickel dilution to the HAZ. I need to meet impact requirement on FL, FL+2mm and FL+5mm. Do you have any other filler metal recommendation?

By js55

Date 02-18-2016 20:27

I just don't think you're going to get your FL +2 or +5 with F22 at that temp.
F22 has a ductile to brittle well above that temp.
Nickel alloys essentially have no ductile to brittle at all.
However, if you are not comfortable with 625 you might try NiCrMo-10.
In any case, it isn't the weld metal at issue as much as the HAZ's.

By Arash486 Date 02-18-2016 21:03

Thanks a lot. Have you had any experience with NiCrMo-10 with PWHT? In my case that I need to meet maximum 250 HV10 hardness on the HAZ, I need to have PWHT. NiCrMo-10 gives a really good mechanical properties in as welded condition but I don't know about after PWHT neither on NiCrMo-3> I will appreciate if you can let me know your thoughts.

By js55

Date 02-19-2016 14:33

You are not going to lose much in strength from heat treat of the electrode. I am assuming your regime is 1300 to 1400 F.
But if you tensile test it its going to break in the base metal anyway.
Also, if you are bending I would consider longitudinal bends. Transverse bends will place too much stress on the fusion zone since there is an extreme difference in strength levels for the filler metal to the base metal.