Re: [MW:11118] Porosity issue in CuNi welding

Hi, Cu-Ni welds made without the addition of the deoxidized filler material very often have excessive porosity that is not apparent on the weld surface. For this reason autogenous GTA welds should be avoided. Other good welding practices to avoid porosity include a short arc, about 0.03 inches (0.8mm) and ample weld metal shielding to exclude air from the molten weld metal. Argon is the usual shielding gas and preferred for purging the inside of pipes during root pass welding.   Also pls.find the attached file at "karthik-welding.blogspot.com" might be useful to you.   Thanks & Regards, (Karthik) Karthikeyan.S QA/QC Manager Getabec Energy Co.,Ltd. 379,Moo6,Soi8,Nikhomphatana, Rayong-21180, Thailand. Phone: 0066 38 897035-8 (Off) Fax: 0066 38 897034 Hand Phone: 0066 892512282 --- On Sun, 5/22/11, romio dabre <romiomdabre@gmail.com> wrote: From: romio dabre <romiomdabre@gmail.com> Subject: [MW:11114] Porosity issue in CuNi welding To: materials-welding@googlegroups.com Date: Sunday, May 22, 2011, 1:40 PM Dear All   We have noticed porosity issue in CuNi piping.   Material - ASTM B466 UNS C70600 Pipe Size 1/2" to 6" Pipe Wall hk - 2.77 to 4.0mm Welding Process - GTAW Filler Wire - ERCuNi Welding Position - 6G Purging / Shilding - 99.995 % Ar. Flow rate Shileding 15 - 25 Cfh Flow rate Purging - We have welded  coupons with different flow rate like 15 -25 , 20 - 30 then 30-40 Interpass 100°C Max.   Please note that we have taken all general care like, cleaning, SSwire brush, Grinding wheels etc.   Request your valuable suggestion  & if there is any documentes / articles on CuNi welding pls provide.     -- To post to this group, send email to materials-welding@googlegroups.com To unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.

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The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.