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Up Topic Welding Industry / Technical Discussions / p1-p45 dissimiliar welding,
- - By nosetackle (**) Date 02-02-2008 03:42 Edited 02-02-2008 03:44
Gents,

ENiCrMo-3 would be suitable to weld p1 to p45 by gtaw and smaw ?

Thank you in advance,

T,
Parent - - By CWI555 (*****) Date 02-02-2008 21:52
I think I'd be using a butter layer of 309 between the P1 and the encrmo-3. I believe you'll be ok on the P45 side.

My opinion for what it's worth,
Gerald
Parent - - By js55 (*****) Date 02-04-2008 16:03
If I may, there seems little advantage to buttering with 309. The thermal expansion of the nickel alloys is closer to carbon steel than stainless. Tossing stainless in between the two adds and unnecessary thermal stress. And the nickels generally handle the dilution better than stainlesses anyway. It actually works better, and is used more commonly, when nickel is the interim between carbon and stainless where Ni's thermal expansion matches the carbon on one side, and its austentiic microstructure is more ductile to accomodate the thermal expansion differences on the SS side. I would also question the choice of NiCrMo-3. Why contend with the Mo and Cb. There are cheaper alternatives with less tendency to cracking. NiCr-3 for GTAW and one of the NiCrFe's for SMAW.
Parent - - By CWI555 (*****) Date 02-04-2008 16:37
I'd have a different opinion when the filler is NiCrMo-3. The advantage is in the dilution. It's worked for the nuclear industry repeatedly, don't see why this wouldnt work for this.
Parent - - By js55 (*****) Date 02-04-2008 17:32
Gerald,
It'll work OK I suppose. Its just not necessary IMO. And it adds an additional cost AND stress with 309's COE.
Of course, we weren't told what the service temp, or code would be. Nukes run considerably cooler than many 31.3 type services, or especially fossil fuel plants so that COE is not as much of a factor. But also, as I said, I wouldn't run the Mo-3 at all, unless you're using up already available stock.
If its cool then the 309 COE won't matter much and its just a question of time involved in buttering. If service is hot there are some metallurgical issues with Mo-3 (mostly with CrMo's in high stress-boiler tubes etc-Marty might be able to help us out here-I just don't remember specifics- been too long), but then if its hot then the COE jumps back in.
Parent - - By nosetackle (**) Date 02-04-2008 18:41
Gents,

i dont prefere to apply buttering layer, unfortunately my client likes to create stupid problems so, buttering layer means lots of different variables i should check and report,

why i want to use NiCrMo, because it is ready in my stocks. and it will take ages for me to arrange shipment of NiCrFe,

But as far as i understand i have to use NiCrFe,

thank you gents for all answers,
T,
Parent - - By js55 (*****) Date 02-04-2008 19:18
Unless I'm misunderstanding, you donb't have to use NiCrFe unless your WPS says so. But since, assuming your under ASME, the qual standard is P4X you can switch the NiCrMo for the NiCrFe, being cognizant of course of any engineering issues.
Specialty alloys has some excellent info on their website as far as specific alloy choices for fillers, or at least they used to.
Parent - - By Fredspoppy (**) Date 02-04-2008 21:36
Most of the situations being discussed here would probably be qualified with notch toughness requirements and therefore SEV's come into play.  Per ASME Section IX, the attached indicates that a change in filler metal classification is an SEV.
Parent - - By js55 (*****) Date 02-04-2008 22:08
Since we still don't know the code, unless I missed it, there are no notch toughness requirements under B31.1, and under B31.3 notch toughness requirements for carbon steel material essentially begins at 105deg minimum design metal temp and down (Fig 323.2.2A Curve A at 3" thick shows the highest temperature requiring testing without Stress Ration calc reductions per Fig 323.2.2B). Section VIII is actually quite close to 31.3 since 31.3 took their stuff from Section VIII, the Queen Mother of CVN testing.
For ASME III its essentially notch toughness for all ferritics tested at minimum design temp. Drop weight testing for thicker stuff.
ASME IX doesn't determine when toughness testing is required.
Parent - By CWI555 (*****) Date 02-04-2008 23:21
"Queen Mother of CVN testing".. I'll have to remember that one.
Parent - - By CWI555 (*****) Date 02-04-2008 19:48
There has been a lot of research in the nuke industry after the Alloy 600 issue. As for a nuke running cooler, it depends on which service in a nuke. After it gets out of containment, it's typically B31.1 anyway. When I see a problem such as the one listed here, I'm going to go with a proven solution every time rather than try to arm chair engineer it.

On the other end of the scale going into to cryo temps, I'd say weld it straight as other issues arise.

As for temps found in a boiler, yeah there are some concerns, and yes it would be the wrong filler.

Regards,
Gerald
Parent - - By nosetackle (**) Date 02-15-2008 06:29
Gents,

ER NiCrFe-3 type of solid GTAW rod is not in the Sec. IX, this consumable existing?
ER NiCr-3 + E NiCrFe-3 Combination can be used for joining p1-p45 connections ?

Thanks,

T,
Parent - By CWI555 (*****) Date 02-16-2008 02:46
Go to ASME II 2004 edition Part C SFA 5.11 paragraph A7.3.3, or you can find the bare variant by looking up Table A1 comparison of classifications in which ERNiCr-3 is listed as the corresponding classification in A5.11 for EniCrFe-3.

As for can you weld it.. if it will stand up to the qualification regime yes I'd say so.
Up Topic Welding Industry / Technical Discussions / p1-p45 dissimiliar welding,

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