[Skylineauto]

Did a search and had no luck. Doing a repair on a EGR cooler. Flange is cast stainless, slightly magnetic. That much I do know. I had the following rods at my disposal, 308, 308L, 316L. I was wondering if anyone has some luck with this. The flange is welded to other stainless parts. I did see a miller video about using pulse DC tig to help prevent if not eliminate cracking. Also will this work welding it to a piece of mild steel? What I am trying to accomplish here is to block off the hole in the exhaust by reusing the flange off the EGR cooler. Thanks.

[big gear head]

Wouldn't 309 work?

[Rick_H]

Im with gearhead, if your welding it to mild steel or various grades of stainless (magnetic screams 409 to me on an auto) Id use 309L for sure.

[Poland308]

This heat exchanger is my recent project. It's a brazed plate 316 SS but the flanges that are on it are metric and 409 SS. I had to use the carbon cast steel flanges off the old one to retro fit the new one. So the pic is of sch 40 pipe welded to 409 SS. It is a 309 SS rod for carbon to SS. It's 308 if it's dissimilar grades of SS.

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[Skylineauto]

Thanks for the input! I did manage to find a piece of scrap stainless, 409 for the repair. Once I struck an arc on the cast piece it did weld nicely. Almost like it was a forging, very dense. Got my hands on some 309 rod, 70 amps pulsed at 250hrz. 90% peek and 40% background.Two passes back purged. Worked well. Now to wait a few years to see if it will hold up.