Re: [MW:14376] Acceptance criteria for welding of Cupro-Nickel pipe

Hi

 

I have recently welded similar material and cleared 100% RT.

Pipe/tube material: UNS 70600 Cu Ni 10 Fe 1.6Mn Seamless drawn tubes #   UNS 70600 Cu Ni 10 Fe 1.6Mn Seamless drawn tubes, Dia. 368mm X 6.5mm THK., I.D. 14".

TIG filler wire: AWS No. (Class): ER CuNi
Specification No. (SFA): 5.7
F No.: 34
A No.: --
Size of filler metal: GTAW: 1.6mm, 2.4mm dia.
Shielding Gas: Grade 1 Argon : 99.995%, Flow rate: 10 – 15 LPM
Backing Gas:  Argon, Flow rate: 5 - 10 LPM

Pre-heat temperature (Min.): 20°C
Inter-pass temperature (Max.):  150°C

Initial & inter-pass cleaning: Wire brushing & Grinding. if required. The joint area should be thoroughly cleaned before start of welding.
Oscillation: max. 2.5 X dia. of electrode.
Orifice / Gas Cup size:  # 8 for GTAW
Contact tube to work distance: The arc should be kept as short as possible to ensure that the shielding gas protects the weld pool adequately.

 

Hope this helps.

 

Regards

 

Prem Nautiyal

 

From: Prakash Hegde <pb.hegde@yahoo.com>
To: materials-welding@googlegroups.com
Sent: Monday, May 28, 2012 11:56 AM
Subject: Re: [MW:14372] Acceptance criteria for welding of Cupro-Nickel pipe

Hi! Instead of Using 70:30CuNi use 90:10 CuNi wire with Pulse Tig ,Up slope /down slope welding facilty and ensure proper purging of thye weld , Use higher dia Ceramic Cup   Regards   Hegde--- On Mon, 28/5/12, Anil Hegde <nottyanil@gmail.com> wrote: From: Anil Hegde <nottyanil@gmail.com> Subject: Re: [MW:14369] Acceptance criteria for welding of Cupro-Nickel pipe To: materials-welding@googlegroups.com Date: Monday, 28 May, 2012, 10:11 AM Mr Megnath ,   Kindly clean the joint surface by buffing wheel  & then take RT .   It will get cleared   Regards Anil Hegde     On Sat, May 26, 2012 at 11:57 AM, Megnath <megnath@gmail.com> wrote: Dear friends, We are doing welding (GTAW using 99.99% Argon & 70-30 cnsumable) of CuNi - 90-10 pipe and all of them fall under class 1 pipe and forced to examine the weld by Radiograpy. On review of radiograph, none of the joint gets cleared. The only problem with welding is "POROSITY". As pe our contract, the size of permissible porosity is 0.2t (thickness of pipe is 3,4mm) and even 1mm porosity calls for repair. Could any one share your knowledge on the following. 1. Acceptance criteria for RT of CuNi pipe weld 2. How to overcome from the porosity Best Regards, Megnath -- 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. -- To post to this group, send email to materials-welding@googlegroups.comTo unsubscribe from this group, send email to materials-welding+unsubscribe@googlegroups.comFor 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.

-- 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.