[MW:12609] Re: 12590] CVN Impact test on 304L 2.77mm thick B31.3 piping

The impact tests are not required when the shape/size/thickness of the
element does not allow machining a charpy specimen.
As max OD is 60.3mm and the thick2.77mm. These two combined size
constraint (thickness & radious of curvature) does not allow machining
the charpy specimen in the tube.

To perform impact test it shall be necessary to weld thicker material,
in this case welding energy will not be representative of weld .

Base material TP304L,welded with dedicated filler ER308L.by TIG
process.My experience this configration gives confident good weld
toughness garentees good result,no risk of embrittlement at cryogenic
temprature.

Amit Pahuja
Sr. Welding Engineer
B-Tech Welding, IWE/EWE-IIW,
cswip-3.1, NDT Level-II

On Oct 1, 6:48 pm, "pgoswami" <pgosw...@quickclic.net> wrote:
> Hi Amit,
>
> ASTM A-370,or ASME SA-370  allows impact test on subside specimens.If you
> look at Fig-12, A/SA-370 the smallest allowable thickness is 2.5 mm.Table-9
> provides the acceptance criteria for various sub size specimens.
>
> You client is right , minus(-) 269 deg C is the ultimate for any material.
> Although austenitic S.S is generally though to have sufficient DBTT values
> at this temperature, it's better to prove the same, during fabrication.
>
> B-31.3 concerns are generic, it specifies that impact is not required if the
> width at the notch is less than 2.5 mm.But the discussion of B-31.3 does not
> address such low MDMT as -269 Deg C.
>
> If  you have the Mill supplied MTR TESTED AT -269 DEG c ? and the MTR of
> welding consumables impact tested @ -269 Deg C, then your client may have
> some backup document for acceptance.
>
> Thanks.
>
> Pradip Goswami,P.Eng.IWE
> Welding & Metallurgical Specialist & Consultant
> Ontario,Canada.
> Email-pgosw...@sympatico.ca,
> pgosw...@quickclic.net
>
>
>
> -----Original Message-----
> From: materials-welding@googlegroups.com [
>
> <mailto:materials-welding@googlegroups.com>
> mailto:materials-welding@googlegroups.com]
> Sent: Friday, September 30, 2011 1:05 PM
> To: Materials & Welding
> Subject: [MW:12590] CVN Impact test on 304L 2.77mm thick B31.3 piping
>
> Please I need your assistance:-
>
> I have Helium gas Pipeline 304L to be welded by ER308L ,having MDMT at -269
> Degree Centigrade , but the thickness of my Pipe is 2.77mm , Which is
> exempted from the impact requirements from B31.3 Chapter-III, Table323.2.2
> Column B, B-4, Notes -6, Impact test are not required when maximum
> obtainable charpy specimen has a width along the notch of less than 2.5mm.
> but my client is not ready to accept that condition/constraint of B31.3. he
> needs explanation that How the material thickness(2.5mm) will bear that MDMT
> at -269 Degree Centigrad., even Obtainable charpy specimen is not possible,
> but How to convince the client the material will have the properties at that
> temperature.
>
> Thanks & Regards
> Posting on behalf of: Amit Pahuja
>
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