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How to improve impact test energy value

How to improve impact test energy value

How to improve impact test energy value

(OP)
Dear all,
Is there any way to improve impact test for Heat Affected Zone that failed ? Will PWHT improve it ?
This is for P1-P6 with E309L weld metal, and P6-P6 with ERNiCrMo-3 weld metal, tested at -20C, got less than 10J.

RE: How to improve impact test energy value

Yes, PWHT can imporve notch toughness for certain materials. You would need to have a fine grained material to increase notch toughness. How is this accomplished? Either by having original material specified to a fine-grained practice or use the GTAW process to increase grain refinement within the base metal HAZ. The SMAW process is not effective in obtaining grain refinement in the base metal HAZ.

You might try a temper bead deposition sequence as an option to increase notch toughness if you are locked into SMAW. I have seen this work on most P-No 1 and P-No 3 base materials.

RE: How to improve impact test energy value

Assuming that the low HAZ impact toughness was in the P-6 material, the low value is expected. PWHT may not improve toughness. I have to ask, why did you pick that material for testing at -20C?

RE: How to improve impact test energy value

(OP)
The question came from a friend.
The MDMT is at -27C.
It is nozzle neck (P6) to shell (P1) welding, and nozzle neck( P6) to flange (P7) welding.
The vessel will not be PWHT, but just want to know if PWHT will help.
Will UHA-51 be able to exempt from doing impact test ?

RE: How to improve impact test energy value

If the P-6 material has > .08% Carbon, the nozzle to shell joint requires PWHT. Your freind needs to review Table UHA-32. No impact are required at the MDMT stated.

RE: How to improve impact test energy value

(OP)
Stanweld, thanks.
Can you be more specific where in the code I can find the impact test is not required.
The vessel is SA516-70,
Nozzle neck is SA-268-TP410 and SA-240-410S
Flange is SA-182-F6a, Class 1

RE: How to improve impact test energy value

Section II Part D.

RE: How to improve impact test energy value

jtseng123 are you in Sec VIII Div 1? If so see Part UHA-51(d)(3) (b) & (c), I don't think you can exempt these base metals.

Also, if your flange is a B16.5 pattern -F6a is not a listed mateial, no P-T rating, see B16.5 Table 1A.

Regards,

Mike

RE: How to improve impact test energy value

(OP)
SnTman,
No 13Cr flange rating per B16.5. Gosh, I never pay attention to it since never encountered in the past. Thanks for your good eyes.
What can they do ? Run flange design calc per code ?

RE: How to improve impact test energy value

Run flange calcs per VIII-1 App 2

RE: How to improve impact test energy value

(OP)
The rating for this vessel 150# based on C.S. (design condition 775F at 60 psig). Most of the 150# standard flange verified by code calc will fail. If insisting designed by code, almost all flanges, from 2" to 24", must be special ordered with the size from the calc, including mating flanges. Cost a lot and time consuming, and for future epalcement, becomes impractical.

The question I have is, why no 13Cr flange in the B16.5 ? must have a reason.

RE: How to improve impact test energy value

jtseng123, this has bit me before:) Apx 2 is the only option I know of, if you are lucky a B16.5 pattern will make.

Just about any flange vendor will sell you B16.5 pattern flanges in 12-13 Cr, without mentioning they are not listed.

Quote: "The world is full of things you can buy. Not all of them are suitable for use in ASME Code pressure vessels." (me)

Regards,

Mike

RE: How to improve impact test energy value

(OP)
SnTMan,
I just called a flange supplier, the answer is: 13Cr is not recognized as weldable material in B16.5, but they can fabricate from this materail and verified by App 2.
Seems no other way out.

RE: How to improve impact test energy value

Yeah, best of luck:)

RE: How to improve impact test energy value

(OP)
SnTMan,
Still a problem:
Running App 2 that means most of the standard dimensions from B16.5 will not work, therefore flanges will be special made, that becomes a headache in fabriaciton and maintenance, even may have problem to use standard gasket.

I found a way out if that could be acceptable without going through Appen 2 as follow:
13Cr forging has the same allowable stress as SA-105 at ambient temp but much better allowable stress than SA-105 at 775F.
So I shall be able to call this 13Cr flange as 150# if it is made to the dimensions of B16.5, and put into service without verified by Appendix 2, becasue it has better properties than SA-105.

Any problem doing this ?


RE: How to improve impact test energy value

jtseng123, I don't beleive it is up to you or me, better ask your AI and customer.

Regards,

Mike

RE: How to improve impact test energy value

(OP)
stanweld,
Can you be more specific which para in II-D the impact test can be exempt.

I check B31.3, for the 13Cr pipe and flange, it seems impact test is not required at -20F and warmer per material note (6), although note (35) gives some warning about low ductility/ low impact properties at room temp. And in Table 323.3.5, P6 P7 shall be tested by lateral expansion, not energy impact test. If impact test can not be waived by II-D, can it be done by lateral expansion test per B31.3 ? My friend is running into all kinds of troubles now.

RE: How to improve impact test energy value

The MDMT for the 12 Cr materials defined is -20F.

RE: How to improve impact test energy value

(OP)
stanweld,
I reviewed UHA-51(d)(3) (b) & (c) that snTman mentioned with our welding engineer, and the conclusion from there is that imapct test can not be waived because thickner nozzle neck and flange are used, and the lateral expansion has to be measured per UHA-51(a)(2) in lieu of energy value. He could not find where you can take exemption at -20F. Would you mind pointing more detail in code II-A or D ?

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