<Big Snip>

What alloy do you guys use?  SS (like 321) will fail much more easily at
1700 than inconel; especially if under any stress loads.  It gets
inter-granular stress corrosion and loses it strength.

Al

"Del Johnson, North Point Solutions, Inc" wrote:

Inconel is really costly if you only need small quanitites.  In December I
purchased some aluminum tube bends from a company in Michigan.  I asked the
salesman if they deal in Inconel.  He said that if your only buying a foot
of tubing for a 90 degree bend it might cost $100 for the raw material but
if your talking 50 or a hundred feet of the material the costs comes down
dramatically.  I asked him to give me a price quote on some 90 degree and 45
degee bends plus some straight material for 10 exhaust systems and 50
exhaust systems (I guessed on quantities of bends and straight pieces) and
told him that we might be able to put together a quantity group purchase.
He emailed me the prices but they don't seem to be in my inbasket anymore.
The prices were a lot cheaper than Burns Stainless (they only have a large
radius 120 degree bend).  If there is interest in going together on a group
purchase I can contact the salesmen and get another quote.  My problem is
that I'm not at a point of knowing what I/we need for bends.

I was able to pick up 120' of 1.5" inconel and some filler rod very cheap.
The guy that does my welding is going to practice on a small piece of it.
He might be interested in welding up exhaust systems if we could standardize
on the design.  He is an machine shop and welding instructor at the Lansing
Community College but has his own equipment so he can do jobs on the side.

Let if there is interest in a group purchase.  If I get enough positive
replies I will look get back with the salesmen to see if he can resend me
the quote which will give us an idea of what 90 and 45 degree bends cost.
We will have to get a final quote from them if we decide to go ahead with a
group order.  There are going to be different requirements for Turbo vs NA
and 13B vs 20B.  The salesmen will give us a cost per bent/type and the cost
of straight tubing so it doesn't matter if there are 4,5...n number of
designs.  The more bends that they do of the same type the cheaper per bend
it becomes so if we can standardize on bend radius that would be helpful.
They can leave whatever lenght straight tail piece that is needed. Also,
they can bend down to a very tight radius.  He suggested 3" radius as the
minmum for 2" inconel tubing.

 
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