Tom,
Did you find out how to gas weld inconel?  What type of rod?  Is a flux

needed (if

so, where do you get it?)?

Ken Powell

Tom Kendall replied:

The guy I contacted faxed about 70 pages of data from a manual on Inconel (I
get a nice fax subsidy from the Boss ;-)  ).  In the section on welding it
goes on at length and with great detail about various gas-arc processes, but
nothing on *gas*.  I get the distinct impression that nothing was said about
gas welding because (most) anybody willing to spend the $$ on Inconel is not
going to waste money in an industrial / production environment on something
as time consuming and labor intensive as gas welding.  Also, TIG, MIG, etc.
leave a much smaller heat affected zone and be less likely to have defects.
Preferred if available.

However, in a chapter on Inconel 600 joining it says "Inconel 600 is readily
joined either to itself or to other metals by standard welding, brazing, and
soldering processes."  Goes on to say that the filler material for
oxy-acetylene welding is Inconel Filler Metal 62.

The various tables and descriptions on how to work Inconel 600 describe
something that sounds very much like austinitic stainless steel (and even
says so in several locations) when it comes to handling.  Can be drilled,
hacksawed, etc. with care to not cold work it to the point that it is too
hard for standard tools.

Inconel 600 was recommended by the vendor as an alloy that met my criteria
for workability with standard (read "home shop") tools, gas weldability
without special pre- or post-heat treat, availability, and high temperature
strength and corrosion resistance.

FWIW:  We've been using Inconel 600 in the nuclear industry for decades.
Pretty good stuff.  Pretty expensive stuff.  Use it for corrosion resistance
in high pressure vessels with clean water.  There's been some problems with
microstructure cracks in it after 20+ years of service in boric acid systems
at temperatures around 600 deg F.  But it has been associated with high
cyclic stresses from thick vessel walls and thermal cycling, and *never* was
where it could be readily inspected (read real high radiation fields).
Nothing I would be concerned about for aircraft manifold use though.

 
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