RE: [MW:16328] Filler wire for Aluminium to CS TIG welding

I saw your query in LinkedIn also.  Aluminum could be welded to steel a couple of ways, e.g friction stir welding, explosion bonding, not certainly by Arc Welding Process. Some of the problems are  as stated below.

 

• With respect to fusion welding say, GTAW iron and aluminum are not compatible metals. Their melting temperatures differ greatly: 1220°F for aluminum vs. 2800°F for iron.
• Both metals have almost no solubility for the other in the solid state, especially iron in aluminum, and several brittle intermetallic phases can form (FeAl, Fe2A1, or FeAI3)'
• Consequently, resultant fusion welds joining steel and aluminum would be extremely brittle.

 

For the sake of  fabrication your only option would  braze welding or brazing. However for a heat exchanger I have  doubt if Sec-IX  welding qualification criteria could be met for such a joint.

 

Aluminum  to steel  combination is popular in ships, as ship super structure contains  extensive  Aluminum alloys for the  sake of  weight reductions. Friction or explosion bonded inserts are used be used as intermediatory to facilitate GTAW  or GMAW. This is not the choice for process equipments e.g heat exchangers.

 

If the MOC aluminum on the tube side, then preferred tube-sheet would be either Aluminum or C.S Tube sheet clad with Aluminum.

 

Wherever C.S# Aluminum welding  may occur ,  facilitate the design change  for Aluminum to aluminum welding.

 

Thanks.

 

 

 

Pradip Goswami,P.Eng.IWE

Welding & Metallurgical Specialist

Ontario, Canada.

Email-pgoswami@sympatico.ca,

pgoswami@quickclic.net

 

1. http://www.esabna.com/us/en/education/knowledge/qa/Can-I-Weld-Aluminum-to-Steel.cfm

 

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From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Prakash Hegde
Sent: Monday, December 24, 2012 10:28 PM
To: materials-welding@googlegroups.com
Subject: Re: [MW:16322] Filler wire for Aluminium to CS TIG welding

Dear Mr Ashok As far as I know We can not weld Aluminum to CS  except Brazing Regards   Hegde p.B. --- On Mon, 24/12/12, Ashok Shende <shendeashok08@rediffmail.com> wrote: From: Ashok Shende <shendeashok08@rediffmail.com> Subject: [MW:16315] Filler wire for Aluminium to CS TIG welding To: materials-welding@googlegroups.com Date: Monday, 24 December, 2012, 9:32 AM Dear experts we are having a project of aluminium heat exchangers with tube side MOC as aluminium SB 209. Here I want to make confirm the suitable filler wires for TIG welding of Aluminium to SA 516 GR 60/70. Thanks in advance. Catch India as it happens with the Rediff News App. To download it for FREE, click here -- 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/ http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm   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.