[Otto Nobedder]

I don't often ask a question here, as I'm not often called to do something I'm not already familiar with (a shame, really, because I like trying new things), so I just absorb new knowledge from others' questions and answers.

However, I'm replacing a structural component, originally 304, with 316. The backstory is, there were many cracks in the original part, every one originating under a gusset that was MIG welded both sides and not closed at one end. The client's engineers' working theory is that the road de-icing chemicals other than salt, commonly use in northern states and Canada when it's too cold for salt to be effective, or during salt shortages, gets trapped in the space beneath the gussets, between the MIG fillets. I've seen evidence that seems to support this.

As an experiment, I'm repacing the damage with 316, and will be welding it to a stub-out of undamaged 304 that was not under the gussets (there were corner cut-outs).

The weld must be vacuum-tight, and will be structural in a load-bearing member. Vacuum-tight is not an issue, but:

Should I make the weld with 308, or 316 rod? Or will it matter from the standpoint of strength and ductility?

Steve S

[Otto Nobedder]

Here's the structure I'm repairing.

GEDC0516.JPG (196.2 KiB) Viewed 891 times

And here's the component I'm replacing.

GEDC0555.JPG (198.64 KiB) Viewed 891 times

[weldin mike 27]

Hey mate,

Heres a link, i hope its what you're after. I find that Lincoln offer a no fuss system of answering questions.

http://www.lincolnelectric.com/en-us/su ... etail.aspx

Mick

[Otto Nobedder]

Thanks, Mick,

It's a piece of the puzzle... It suggests 309 is out because of the absense of Molybdenum, which is a component of 316. I'll have to check 308 for content.

Steve S

[weldin mike 27]

Hey,

dang nearly got it. Try seaching that area of the lincoln website, i think youll'll find what you want.

Mick

[weldin mike 27]

Hey,

Have sent you an email on this subject.

Mick

[Alexa]

OttoNobedder.

If you are welding 316, then 316 filler is recommended.
Respect the upper limits on heat input and interpass temperature.

Alexa

[Otto Nobedder]

Thanks, Mick,

Got the e-mail. Much appreciated.

Steve S

[weldin mike 27]

No worries mate. May need to print the table out to avoid a sore neck... (Sorry everyone else, inside joke . )

Mick