Welding Steam Pipe to Stainless Steel

[raddavey]

Ok im making a steam pipe turbo manifold but i got the collect made in stainless steel. Will it be ok to weld the two together? I'm pretty sure they'll weld fine but i'm worried about the different expansion characteristcs possibly causing the joint to crack.

[Rz]

you can get your steampipe bends in s/s you know , if you havent allready gone and bought mild steel ones.

[Stix Zadinia]

do you need TIG to weld S/S correctly?

[Rz]

nope it can be mig welded.
tig usually allows for a much easier weld around a something like a small pipe though.

[BigMuz]

Mig or stainless MMAW rods (stick).

[stockymcstock]

i've done stainless to mild with the stick welder, although not in very high heat applications.

my advice would be to use stainless rods to do it. i reckon it'll be fine.

[raddavey]

I've already made two of the runners and have all the steam pipe bends. I was going to copy the stainless merge collector but found cutting the angles too difficult so just wanted to weld the one i have on since its made perfect.

I"m using stainless rods with an ARC welder. Same way i did my intercooler pipes. Actually i find welding with the stainless easier than mild steel.

[stockymcstock]

yeah it flows on nicer i reckon. go for it, if it breaks you can make another, better one.

[PHULL]

Won't you have to purge the inside of what you are welding for SS?

[RSWEPN]

stainless to mild is fine, alot of the guys in the US who make manifolds for Honda's use stainless pipe with mild steel flanges, and comes up a treat

[stockymcstock]

stainless pipe with mild steel flanges

i've done that a fair bit, no worries. stick welded using 1.6mm stainless rods and like 40 amps. it requires some specific techniques to work properly but it can be done.

[Gravitykills]

309 wire( you can get electrodes as well) is used to join stainless to mild, pretty much all grades. We use it join 341 to 2 1/4 chrome among others, passes radio and 3000 psi service all the time.

[raddavey]

im just using 2.5mm electrodes with a really old arc welder. But it welds nice. Just have to go slow and basically run a whole series of tack welds next to each other. Otherwise it just burns big holes. Plus it looks kinda like its been TIG welded that way anyway.