317L Overlay Welding Redux 3

[Guest102023]

https://www.eng-tips.com/viewthread.cfm?qid=191359

I've been pondering options for the butter layer for an ultimately 316(L) corrosion-resistant weld overlay to achieve:
[ul]
[li]full 316 Cr-Ni-Mo chemistry in the 2nd layer (getting carbon down to 'L' range is very unlikely);[/li]
[li]achieving a reasonable ferrite number in the 2nd layer of say 4~10FN;[/li]
[li]using GMAW-machine with oscillation or SAW-twin wire (2 x 3/32"Ø side by side; DCSP);[/li]
[li]A516-70 steel substrate[/li]
[/ul]

Minimum 2% Mo is impossible in the 2nd layer without including Mo in the butter layer (especially considering 316L products are typically around 2.2% Mo, so 309L+316L doesn't get you to 2% min. Mo, at least not with conventional weld processes).

317L is not industry standard and it is not one I have used before, but looking at the nominal composition it should be a good candidate. If you take 309L and replace 3.5% of the Cr with Mo you get composition that is surprisingly similar to 317L, and you guarantee 2% min. Mo in layer 2. I'm also considering the difficulty in sourcing 309MoL.

Any thoughts or experiences with using 317L directly on steel?



"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[TugboatEng]

A516 is a plate standard. Would it not be more economical to do explosive cladding and skip the puddling of metals all together?

https://www.nobelclad.com/en/process/explosion-welding

 

[kingnero]

Are those the only available welding processes? Can't you work on a lower dilution, giving you more options afterwards?

And in Europe, P355 explosion bonded with 316 is an off-the-shelf material, Tug's idea is a good one...

 

[MintJulep]

Explosion clad was the first thing that came to my mind also.

 

[Guest102023]

Well if I wanted explosion cladding then the question becomes moot doesn't it?

The question was sufficiently specific and included the words 'weld' and 'overlay'. I also added the word 'experiences', meaning people from the welding community who have been there, done that.


(TBE you should stick to doing what you know, poisoning Climate Change threads. Or are you just stalking here?)

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[EdStainless]

I have seen this weld overlay done with 1.4435 (higher Cr, Ni, and Mo than 316L) filler.
If you keep the dilution down the second pass looks pretty good.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[TugboatEng]

You're welcome, stoner.

We do clad welding on propeller shafts so I would not say zero experience.

 

[Guest102023]

EdS,

Schaeffler says I should be safe at up to around 25%, which I can get with those weld processes. With SAW I assume some loss of Cr to the slag, up to 1%.

I’m just a little surprised not to have heard of this being attempted when it looks like it should work well. I’ve seen 316 back cladding on polymer reactors fail in various ways, mostly by folks (including career WEs) not understanding dilution and what is required to achieve a weld as corrosion resistant as the adjacent roll or explosion clad base metal.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[TugboatEng]

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[Guest102023]

pickle, meet butt; butt, meet pickle

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[TugboatEng]

We get it, you can't do det-clad because you already built the vessel and now have to do weld clad to repair it. You don't have to be so mean to us.

 

[SJones]

https://www.eng-tips.com/search.cfm?q=317L+overlay&action=search

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[weldstan]

For sub arc, use a reinforcing Cr added flux to prevent Cr loss. While I never had a problem sourcing 309MoL for the same 2 layer overlay with GMAW and SMAW processes, I hope you can find it now. You can always try the 317L approach though and it could be quite effective.

 

[Guest102023]

Thanks Steve,
I did the same search as well as google and did not find the specific answer I am looking for.

weldstan,
I am aware of those. The reasons I am considering 317 for all layers are: higher Mo than 309MoL in the first layer (and therefore 2nd also); and simplicity of the WPS - a single classification for the entire job.




"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[Guest102023]

Try to ignore Tug folks. He is only here to stalk me over my apparently radical views on climate change (that it is real and happening now). I've been sworn at and called nasty names and had my mental health questioned. With death threats being widely and cheaply available these days I would not be surprised if those follow shortly. It is the price one pays for being educated and aware in 2022. (Whatever happened to site moderation?)

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[SJones]

@brim

ASM Stainless Steels offers 317L as as a possible first layer for a subsequent layer of either 316L or 317L. Did your Google search throw up: Characterisation Of AISI 317L Steel Weld Cladding On ASTM A516 Gr60 Steel Used In Oil And Gas Sector, M M Silva et al, Proceedings Of COBEM 2009?

Steve Jones
Corrosion Management Consultant

http://www.linkedin.com/in/drstevejones

All answers are personal opinions only and are in no way connected with any employer.

 

[Guest102023]

Thanks Steve,

Is that ASM reference an old book (like from the 80s)? I might have that.
The other reference I already found, but the welding process is boutique (twin wire GMAW, very small diam. by the looks of it), and the welding setup and parameters are not provided. I was not impressed by the experimental setup for the information they wanted to obtain, but it at least showed it can be done metallurgy-wise.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[EdStainless]

I would still rather see both passes done in 316LMo (2.5 min Mo) than use 317L.
My bias in this is the risk of people messing up the two different filler metals.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed

 

[Guest102023]

EdS,

Good point, but with Mo in 316L typically so little over the 2.00% minimum, #1 309MoL + #2 316L is iffy for Moly content. That approach is no more error-prone than #1 317L + #2 316L. Also the 309MoL you need to stock (not mention source) is useful for this one task only.

If it is for naphthenic acid service (3% Mo min.) you would want to go with 317L for all layers, which is less error-prone.

"If you don't have time to do the job right the first time, when are you going to find time to repair it?"

 

[EdStainless]

That is why I said 2.5% min Mo 316L.
In Europe it is known as 1.4435 and in the US as S31682. (called 316LMo or 316LMn)
This will let you get your second pass above 2.0% Mo.
If you want more then do both layers in 317L.

= = = = = = = = = = = = = = = = = = = =
P.E. Metallurgy, consulting work welcomed