347 filler on 304 SS?

[shovelon]

Hey guys.

I have been doing the research and the chemistry of ER347 filler looks to be compatible with 308 for welding 304 alloy stainless steel. Is there any downside to using 347 other than cost?

TIA.

[taz00]

Not really.

[ZTFab]

From Burns Stainless;

2. What size filler rod should I use? - For welding 18g, 16g and even SCH 10 stainless steel, we recommend a 0.030” diameter rod of the appropriate base metal. We recommend 308 rod for welding 304 to 304 as well as 304 to 321. We recommend 347 rod when welding 321 to 321 and when welding mild steel to 304, a special 309 rod for dissimilar metals is recommended. We have found that 347 rod can be used for most 300-series stainless steel welding applications.

http://www.burnsstainless.com/WeldingFAQs.aspx

[taz00]

347 is essentially 304 with small additions of niobium to stabilize it. Stabilization of a stainless steel essentially means adding an element that will form carbides when exposed to higher temperature. Otherwise the chromium forms carbides thus reducing the corrosion resistance.
347 is used mainly when welding 321 (321 has small additions of titanium to form the carbides) or 347. The reason 321 is not used so much as a welding consumable is the fact that Ti is easily burned in the arc making it a less than ideal choice.
Although 347 could be used for welding 304 it is less than ideal for welding 316 since it lacks the molybdenum that gives 316 its superior pitting resistance.
I hope this was of some help.

[weldermike]

347 is essentially 304 with small additions of niobium to stabilize it. Stabilization of a stainless steel essentially means adding an element that will form carbides when exposed to higher temperature. Otherwise the chromium forms carbides thus reducing the corrosion resistance.
347 is used mainly when welding 321 (321 has small additions of titanium to form the carbides) or 347. The reason 321 is not used so much as a welding consumable is the fact that Ti is easily burned in the arc making it a less than ideal choice.
Although 347 could be used for welding 304 it is less than ideal for welding 316 since it lacks the molybdenum that gives 316 its superior pitting resistance.
I hope this was of some help.

[MinnesotaDave]

Now Mike, are you saying that it wasn't of help?

Looked pretty straightforward to me...I think at one point my brain switched to pistol calibers and then back to stainless

[shovelon]

Thanks guys.

I have been using 347 filler required by the customer on 321 to 304 applications and it flows like butter. A whole lot like Super Missile Rod(not quite the match), but a lot cheaper. I have one part that landed in the shop that several others gave up on. Includes a purge, heat sink, and a poor fit. Free flowing filler like 347 would help greatly. 308L just does not want to get out of it's own way it sometimes. But aside from that 347 just seems to be fast as hell and stable.

I am trying to put together a set of documents to substantiate my choice. I am still crunching the data on this doc. http://www.aws.org/wj/supplement/WJ_1984_07_s231.pdf

[shovelon]

347 is essentially 304 with small additions of niobium to stabilize it. Stabilization of a stainless steel essentially means adding an element that will form carbides when exposed to higher temperature. Otherwise the chromium forms carbides thus reducing the corrosion resistance.
347 is used mainly when welding 321 (321 has small additions of titanium to form the carbides) or 347. The reason 321 is not used so much as a welding consumable is the fact that Ti is easily burned in the arc making it a less than ideal choice.
Although 347 could be used for welding 304 it is less than ideal for welding 316 since it lacks the molybdenum that gives 316 its superior pitting resistance.
I hope this was of some help.

And that is what I am hoping for, that the addition of stabilizing components just makes it a better choice for 304. And this is for tig applications.

[shovelon]

Now Mike, are you saying that it wasn't of help?

Looked pretty straightforward to me...I think at one point my brain switched to pistol calibers and then back to stainless

So you were thinking 347 magnum eh?

[MinnesotaDave]

So you were thinking 347 magnum eh?

I hear it wets out good

[weldermike]

I hear it wets out good

Found this college video of Dave and his buddy.

[taz00]

I did a quick read on the AWS article, interesting but could not find any reference to 304 welded with 308.
In any case a chain is only as strong as its weakest link.
Welding 304 with 347 will not give you any advantage since it will be the base metal that will govern the final result.
If that were the case then you could get even better results welding with some nickel alloy.
Ease of use is another matter though and since metallurgically 347 will not cause any problems I see no reason in not using it if you find it easier to work with (aside from cost)

[MinnesotaDave]

Found this college video of Dave and his buddy.

Oh good lord....I'm sorry I even watched them! LOL

Lost more IQ points watching them than when I watched Mr. Tig

[storeman]

In case anyone is interested, I have about 2 dozen cans of NOS USA-made 347-15 stick electrodes (SMAW). Six to 10 lb cans, 10"-14" lengths, depending on manufacturer (Mc Kay, Arcaloy, Lincoln, etc.,), All sealed in undamaged cans. Most are 3/32"
If interested, PM me.

[Oscar]

Thanks guys.

I have been using 347 filler required by the customer on 321 to 304 applications and it flows like butter. A whole lot like Super Missile Rod(not quite the match), but a lot cheaper. I have one part that landed in the shop that several others gave up on. Includes a purge, heat sink, and a poor fit. Free flowing filler like 347 would help greatly. 308L just does not want to get out of it's own way it sometimes. But aside from that 347 just seems to be fast as hell and stable.

I am trying to put together a set of documents to substantiate my choice. I am still crunching the data on this doc. http://www.aws.org/wj/supplement/WJ_1984_07_s231.pdf

have you tried 308LSi? I've read on Welding Tips n Tricks that the added Si helps with impurities while at the same time lowering the melting temp just a smidge and allow it to wet out a smidge better than 308L. I haven't tried it out though. It's even cheaper than regular 308L, diameter for diameter, from what I've seen.

[Hillbilly2008]

Structurally, I repeat, STRUCTURALLY, all 300 series stainless steels (with the exception of 330 grade) can be welded with any other 300 series filler (again, with the exception of 330). It's when you get into the other desired properties of the specific grades of stainless that you start mixing and matching filler metals with the base metals (ie; strength at elevated temperature, resistance to acid/caustics/corrosives, food grade properties at high temps, etc).

200 series are also weldable with 300 series fillers, and 400 series are weldable with 300 and 400 series fillers. Sometimes, when certain 400 series (ferritic-type) are welded with 400 series fillers, preheat is required.

-Hillbilly

[shovelon]

have you tried 308LSi? I've read on Welding Tips n Tricks that the added Si helps with impurities while at the same time lowering the melting temp just a smidge and allow it to wet out a smidge better than 308L. I haven't tried it out though. It's even cheaper than regular 308L, diameter for diameter, from what I've seen.

No I have'nt. Sounds promising. I can readily buy 347, and got a good price from my laws.

[shovelon]

Happy to say I ordered the ER347 filler and holy cow is it nice.

[weldermike]

Happy to say I ordered the ER347 filler and holy cow is it nice.

Well then lets see some kick butt weld pics broski! I always enjoy looking at your welds, but they only appear once in a very blue moon.

[shovelon]

Well then lets see some kick butt weld pics broski! I always enjoy looking at your welds, but they only appear once in a very blue moon.

Emm ok, these I am working on today. Got to use the 347 second image. Me like.

Fillet weld-.030" 304 ss, Er308L filler with argon backpurge otherside.



Single groove butt weld-.040" 304L ss, Er347 filler, backing block only to catch gas.

[A_DAB_will_do]

Hey guys.

I have been doing the research and the chemistry of ER347 filler looks to be compatible with 308 for welding 304 alloy stainless steel. Is there any downside to using 347 other than cost?

TIA.

You're on solid ground shovelon. I've known some welders to use 347 when doing quick and dirty (and not to code) boiler tube work. The added Niobium helps soak up carbon contamination from soot and other crap that finds it's way into the weld pool. I'm not recommending it, but more than one guy has told be that if the welds are showing porosity using 308L TIG rod, that 347 will get the job done.

The greater 'ease-of-use' is just a free benefit.

[shovelon]

You're on solid ground shovelon. I've known some welders to use 347 when doing quick and dirty (and not to code) boiler tube work. The added Niobium helps soak up carbon contamination from soot and other crap that finds it's way into the weld pool. I'm not recommending it, but more than one guy has told be that if the welds are showing porosity using 308L TIG rod, that 347 will get the job done.

The greater 'ease-of-use' is just a free benefit.

Thanks! That is what I was looking for.

[MinnesotaDave]

Niobium is a new one for me, never heard of it.
Found this interesting about it:

"Niobium is an effective microalloying element for steel. Adding niobium to the steel causes the formation of niobium carbide and niobium nitride within the structure of the steel.[21] These compounds improve the grain refining, retardation of recrystallization, and precipitation hardening of the steel. These effects in turn increase the toughness, strength, formability, and weldability of the microalloyed steel.[21] Microalloyed stainless steels have a niobium content of less than 0.1%.[55] It is an important alloy addition to high strength low alloy steels which are widely used as structural components in modern automobiles.[21] These niobium-containing alloys are strong and are often used in pipeline construction."

[shovelon]

Niobium is a new one for me, never heard of it.
Found this interesting about it:

"Niobium is an effective microalloying element for steel. Adding niobium to the steel causes the formation of niobium carbide and niobium nitride within the structure of the steel.[21] These compounds improve the grain refining, retardation of recrystallization, and precipitation hardening of the steel. These effects in turn increase the toughness, strength, formability, and weldability of the microalloyed steel.[21] Microalloyed stainless steels have a niobium content of less than 0.1%.[55] It is an important alloy addition to high strength low alloy steels which are widely used as structural components in modern automobiles.[21] These niobium-containing alloys are strong and are often used in pipeline construction."

Typical niobium content of 347 is .05%, so that makes sense for grain stabilization and thus puddle stability. Cool. Also looks like a better filler all the way around than 308L for grain refinement.

[weldermike]

Nice work Terry!