Inconel filler metal for 2205 duplex stainless

[Talon170]

Hi All, I am posting this question on forums due to lack of information available. We fabricate 2205 duplex stainless steel pipe assemblies used in the flue gas desulphurization process. We have always used the recommended 2209 filler metal. Recently we have received notice that our WPS for using 2209 does not meet the customer's standards and they are requiring us to certify and use ERNiCrMo-03 (Inconel) filler metal for the 2205 duplex.

I am concerned about this simply because nowhere can I find any information that says this is acceptable and why. I have heard comments that the Inconel can affect the Nitrogen in the HAZ. But I am not sure, that was just one person and can find nothing to back that statement up. If anyone has any info/opininons concerning this, let me know. It would be much appreciated.

Thanks!!

Dave

[usmcpop]

Here's some general info (pretty detailed)., though no mention of Inconel for 2205.

http://www.stainless-steel-world.net/duplex/ShowPage.aspx?pageID=12

I'd be tempted to contact the metal and/or weld filler suppliers.

Here's a blurb on one brand of ERNiCrMo-3 filler http://www.specialmetalswelding.com/...tash/fm625.pdf

[Talon170]

Here's some general info (pretty detailed)., though no mention of Inconel for 2205.

http://www.stainless-steel-world.net/duplex/ShowPage.aspx?pageID=12

I'd be tempted to contact the metal and/or weld filler suppliers.

Here's a blurb on one brand of ERNiCrMo-3 filler http://www.specialmetalswelding.com/...tash/fm625.pdf

Thanks for the links. I had been to that S.S. world website before but completely forgot to check there. After some digging on their website, I did find one document that backs up a statement I had read elsewhere concerning the Niobium in the Inconel rod affecting the Nitrogen in the 2205. This is what I was looking for. Now, if I can just convince the Customer.................

[usmcpop]

They are in some high-tech territory with some of those alloys. It's a kind of hobby of mine to delve into some of these things, especially since my kid is welding Inconel 738 turbine blades with 625 filler, and doing other stuff with Hastelloy, etc. (All of the stuff has specifically developed in-house procedures, and all of the product is inspected with fluorescent dye, etc.)

I suppose you have to worry about not only on the initial strength of the joint, but corrosion, temperature, long-term stress cracking and the whole lot. Let us know how you make out. Inquiring minds want to know.

[G Austin]

I have seen this requirement in the fabrication of 2205 scrubbers and absorbers. It is typical in that type of fabrication. There is greater flexability with the nickel alloys as far as controlling nitrogen in the deposited weld metal from what I remember. I believe I have some papers on the subject from when I was a little more deeply involved.

[brianpgriset]

Hi All, I am posting this question on forums due to lack of information available. We fabricate 2205 duplex stainless steel pipe assemblies used in the flue gas desulphurization process. We have always used the recommended 2209 filler metal. Recently we have received notice that our WPS for using 2209 does not meet the customer's standards and they are requiring us to certify and use ERNiCrMo-03 (Inconel) filler metal for the 2205 duplex.

I am concerned about this simply because nowhere can I find any information that says this is acceptable and why. I have heard comments that the Inconel can affect the Nitrogen in the HAZ. But I am not sure, that was just one person and can find nothing to back that statement up. If anyone has any info/opininons concerning this, let me know. It would be much appreciated.

Thanks!!

Dave

Let me take a look at a few resources at work and I'll get back on here...

[brianpgriset]

I've looked through a few technical documents and could not find anything negative about using Inconel 625 filler. However, every welding procedure I looked at instructed the use of the ER2209 you mentioned. One procedure specifically mentioned to use filler wire with at least 0.14% Nitrogen. The spec sheet of the Inconel 625 did not list any nitrogen content, so perhaps there is a chance nitrogen content in the weld area would be depleted. Also, it mentioned in the spec sheet the Inconel is intended for use in highly austenitic stainless steels. Duplex, of course, is a 50/50 split so that may affect the weld zone, leaving it low in martensite possibly?

[THRUWALL]

When not using 68,55 use 112t