308L vs 309L wire

[Llama]

Hi all,

I'm after some 309L wire, mostly for welding dissimilar metals and cold cast iron welding. However the problem is that on this side of the globe it is rather hard to get a hold of in small quantities (In NZ it only comes in 15kg rolls, and mostly 1.2mm with a few places selling 1.0Si, which is super pricey).

The reasons I want 309L is for welding dissimilar metals, and I am also going to attempt cold welding cast with it. From what I have read I could also use it weld normal 304, which would make it even more versatile.

308L can be had in reasonable quantities over here for a good price, but what is going to happen if I try cold weld cast or dissimilar metals with it? I know the chromium, nickel and molybdenum contents differ, but this doesn't mean much to me

 

[TechnicAl]

As for cold welding Cast Iron 308L will do the same job as 309L..........a BAD one

For Cast Iron you need Ni or NiFe with the correct coating for "cold welding" which is graphite. The Nickel doesnt absorb Carbon in the same way as the stainless will and therefore doesnt become brittle. The carbon comes from the Cast iron and from the coating.
The "cold" part is a comment on the fact that they run at lower amps than conventional coated electrodes.

Even if its MIG the SS will embrittle whereas the Ni / NiFe wont

 

[shenion]

I did my horizontal band saw base with 308L. It worked fine but was near impossible to drill as it was so hard.

It has held up fine over the years though.

 

[TechnicAl]

I did my horizontal band saw base with 308L. It worked fine but was near impossible to drill as it was so hard.

It has held up fine over the years though.

If its that hard the likelyhood of cracking increases. Sometimes things work when they shouldnt. There will be an explanation as to why your job worked but for most jobs the theory will prevail.