Welding 304L to 321 1

[berkshire]

Welding 304L to 321 SS
I had figured on using 347 welding rod to tig weld a tube spigot made of 304L to a 321 exhaust pipe. The tube is a condensate /rainwater drain.
A colleague of mine said Inco 82 would do a better job because of the higher nickel content.
I figure this is a situation where a little knowledge is dangerous. What are the pros and cons of using an inconel rod here?
B.E.

 

[unclesyd]

Can you give a little more about your application, like what is the environment that the material will see?
In other words do you still need to corrosion resistance of SS?

 

[Metalguy]

You should be able to use 308L or 309L rod. Alloy 82 is harder to weld with than stainless-the weld puddle is like molasses, and is extremely susceptible to cracking if traces of lead or sulfur compounds are present.

 

[Goahead]

Your original selection, 347, is quite acceptable.
The Avesta Welding Manual is available at no cost from

http://www.avestawelding.com

Regards,

http://www.welding-advisers.com/

 

[berkshire]

unclesyd (Materials)
The exhaust pipe is on a seaplane that is used in salt water, however the major concern is getting rid of rainwater collecting in the exhaust pipe, when the aircraft is moored.
Metalguy (Materials)
I do have lead compounds present, residues from tetra ethyl lead.
Goahead (Aerospace)
I am familiar with Avesta products, I use their pickling paste.
All,
It is just as well I asked the question. I did not know about the cracking problems with 82 with lead in the picture. I will stick with my original choice 347.
This is what makes this forum work, no nonsense answers.
B.E.

 

[GRoberts]

I would propose that using the inconel filler metal could actually be detremental in this application. Due to all the heating and cooling cycles, it would be better to use a stainless steel with a CTE that matches the base metal. The nickel alloy has different CTE which would result in higher residual stresses and possibly fatigue cracking.