Hastelloy weldability
Hastelloy weldability
(OP)
Hi,
Can hastelloy (C276 or C22) be welded to stainless steel (304L or 316L)?
We need some directions on what process can be used and if it has been done before.
Thanks in advance.
Can hastelloy (C276 or C22) be welded to stainless steel (304L or 316L)?
We need some directions on what process can be used and if it has been done before.
Thanks in advance.





RE: Hastelloy weldability
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RE: Hastelloy weldability
The welding is required at the area of tubes joining tube sheet in a condenser.
What methods and filler metal can be used to weld?
I did not follow what you meant by the final weld properties. The welding is required to seal any gaps and prevent leaks after the tubes are expanded.
Thank you.
RE: Hastelloy weldability
We have used both methods along with an autogenous weld between the tube and tubesheet.
We often use your combination either in a full bundle or using the C276 as a safe end material for SS.
RE: Hastelloy weldability
Syd is right, it should be done automatic.
What size and thickness are the tubes? If you are only looking for sealing then just do it autoagenous.
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Rust never sleeps
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RE: Hastelloy weldability
We are not sure about temperature swings.
Tube size: 1/2" 20 gage, 3/4" 22 & 18 gage mixed
RE: Hastelloy weldability
RE: Hastelloy weldability
I would definately try to go automatic due primarly to the thin wall tubes which will require the undivided attention of a welder using a manual process. If you have too you can rent a an automatic tube welder
Every tubebundle, over 200 alloy and 50 or so CS, on our site is rolled and seal welded. I don't remember every having any problems on new fabrications. The only problems I've seen has been contamination during a retubing that caused some minor weld problems.
RE: Hastelloy weldability
The joint is almost always done with automatic welder.
Also we need to get a procedure qualified as well. Hopefully it would go without much trouble.
Thank you for all your inputs.
RE: Hastelloy weldability
Very light gage tubes (0.012"-0.018") are usually welded because you can't get strong enough roll joints. I have watched millions of tube ends in 3/4"x0.016" tubing welded using automatic machines.
When tubes are going to be seal welded, often the tubes are installed and lightly rolled, just enough to bring the tubes in contact with the holes. Then they are welded and inspected (dye pen and/or leak tested). After that the tubes are then hard rolled.
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Rust never sleeps
Neither should your protection
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RE: Hastelloy weldability
RE: Hastelloy weldability
You do not want to hard roll the tubes prior to welding.
- It can lead to blow holes from traped gas/moisture in the joint
- It is very difficult to leak test the weld, and only the weld
You must hard roll the joints after welding.
- You need to be careful to stay away from both faces of the tubesheet, rolling the welds can cause cracks, rolling to the back of the tubesheet can cause tube problems
- You need the tubes well supported. If they are 'loose' in the holes and only welded at the front you can get vibration and the tubes rattling in the holes. They fatigue quickly this way.
You must have mock ups that are destructivly tested. And no re-welding unless a joint fails leak test. You don't care if they look good, you want them to work.
= = = = = = = = = = = = = = = = = = = =
Rust never sleeps
Neither should your protection
http://www.trent-tube.com/contact/Tech_Assist.cfm
RE: Hastelloy weldability
If design conditions permit you may want to consider a weld only tube/tubesheet connection
As posted by EdStainless a test setup is an absolute must.