Major Ramifications
Well-known member
Is welding aluminized steel different from welding regular carbon steel? I will be welding some aluminized reducers to my carbon steel headers.
Welding Aluminized Steel - Is it Any Different?
- Thread starter Major Ramifications
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Stinger
Well-known member
No, you won't need to change anything to weld it to the headers. The aluminizing burns away at a lower temp than the steel. You can use a wire wheel to remove the aluminizing if you prefer though.
Professur
Well-known member
But, your weld will be unprotected, unlike the rest of the pipe, and will rust out quickly if you don't coat it.
dragginbalz
Well-known member
You didn't mention which process you are using so I will throw in my two cents... MIG it will be fine. I welded some with TIG a while back and had a hard time not getting porosity , even with the coating ground off.
OP
Major Ramifications
Well-known member
Sorry, guys. I should have mentioned that I will be using my MIG. I didn't realize that the aluminizing was only a coating on the outside, I thought it was something mixed with the steel. Thanks for the responses.
I bought a used set of headers that someone had cut the collector flanges off of and welded the exhaust pipes directly to. I bought a set of ball/socket style 3" to 3" "reducers" and am going to turn them around backwards and weld them on. I'll use another set of reducers that will bolt to these and weld to the rest of the exhaust. That way, I can disconnect the headers for any future repairs.
I plan to coat the completed headers with Eastwood's ceramic header coating.
I bought a used set of headers that someone had cut the collector flanges off of and welded the exhaust pipes directly to. I bought a set of ball/socket style 3" to 3" "reducers" and am going to turn them around backwards and weld them on. I'll use another set of reducers that will bolt to these and weld to the rest of the exhaust. That way, I can disconnect the headers for any future repairs.
I plan to coat the completed headers with Eastwood's ceramic header coating.
89GLH
Well-known member
Lazarus thread!
I'm looking to redo an exhaust system using 3" aluminized steel, and read that 304L stainless wire would work to maintain the corrosion resistance. True or false? I had planned on wrapping the pipe with exhaust pipe wrap anyway, if that matters.
I'm looking to redo an exhaust system using 3" aluminized steel, and read that 304L stainless wire would work to maintain the corrosion resistance. True or false? I had planned on wrapping the pipe with exhaust pipe wrap anyway, if that matters.
Not sure if 304L is for mixing with stainless and non stainless or even other type of stainless....
I know 309L / H you can mix different type of stainless or stainless and regular steel....
Recently I found out about 312L that can do the same thing as 309L but have not used it yet...
but to mig 304L or 309L I think you'll needed the Tri-gas instead of the regular argon or Co2/argon mix.
I don't think there are any differences welding Aluminized steel to regular steel... if you just mig it .... I wouldn't worry about it.... I remember asking this same questions when I build mine. Few years ago.
I know 309L / H you can mix different type of stainless or stainless and regular steel....
Recently I found out about 312L that can do the same thing as 309L but have not used it yet...
but to mig 304L or 309L I think you'll needed the Tri-gas instead of the regular argon or Co2/argon mix.
I don't think there are any differences welding Aluminized steel to regular steel... if you just mig it .... I wouldn't worry about it.... I remember asking this same questions when I build mine. Few years ago.
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304L wire?
Not too common to see that wire. Most common would be using 308/308L wire to weld on 304 stainless. Slight alloy overmatch to maintain the stainless aspect of the stainless steel once it's all welded.
308/308L stainless filler wire for GMAW on aluminized steel exhaust parts? Holy witch's brew of alloys Batman!
Save the stainless filler wire for when you are welding stainless steel workpieces.
Remove the aluminum coating in the weld 'zone', weld the mild steel with mild steel filler wire, wire brush the weld bead to remove the silicon 'islands' left after welding when you use a 70S-6 silicon-deoxidizer wire, paint or coat with your desired high-temp anti-corrosion paint/coating, put your exhaust wrap on.
Not too common to see that wire. Most common would be using 308/308L wire to weld on 304 stainless. Slight alloy overmatch to maintain the stainless aspect of the stainless steel once it's all welded.
308/308L stainless filler wire for GMAW on aluminized steel exhaust parts? Holy witch's brew of alloys Batman!
Save the stainless filler wire for when you are welding stainless steel workpieces.
Remove the aluminum coating in the weld 'zone', weld the mild steel with mild steel filler wire, wire brush the weld bead to remove the silicon 'islands' left after welding when you use a 70S-6 silicon-deoxidizer wire, paint or coat with your desired high-temp anti-corrosion paint/coating, put your exhaust wrap on.
89GLH
Well-known member
^ Perfect! Thank you.
ChristopherMercao
Member
304L wire?
Not too common to see that wire. Most common would be using 308/308L wire to weld on 304 stainless. Slight alloy overmatch to maintain the stainless aspect of the stainless steel once it's all welded.
308/308L stainless filler wire for GMAW on aluminized steel exhaust parts? Holy witch's brew of alloys Batman!
Save the stainless filler wire for when you are welding stainless steel workpieces.
Remove the aluminum coating in the weld 'zone', weld the mild steel with mild steel filler wire, wire brush the weld bead to remove the silicon 'islands' left after welding when you use a 70S-6 silicon-deoxidizer wire, paint or coat with your desired high-temp anti-corrosion paint/coating, put your exhaust wrap on.
Thanks for sharing this.. I agree with you point strongly.
Because Austenitic stainless steels such as grade 304 stainless or grade 316 stainless can be welded to plain carbon steel using MIG and TIG welding. In many cases, when welding dissimilar metals such as stainless and plain carbon steel, weld processes such as MIG welding that use filler material are preferred.
Offthewallds
Member
If I may offer some humble input:
ER308/L is best used for joining austenitic to austenitic (300 series to 300 series).
ER309/L has higher levels of Cr and Ni than 308. When the stainless and mild steel (or aluminized carbon steel) mix together in the weld pool, you create what's known as "additive mixture/admixture/admix". Admix is essentially the child chemistry of its two parents. The higher Cr and Ni from 309 provide the admix with the necessary corrosion resistance, ductility, high temp strength, etc. Moral of the story, when joining a carbon steel to stainless, use 309 if possible.
To the gent getting porosity with GTAW, the aluminum oxide layer varies in thickness based on the ASTM spec, anywhere from .25 mils to 1+. Depending on your cleaning method, it's entirely possible to smear and embed the coating into the base metal if you're using a grinding wheel. Even after using a tigerpaw or scotchbrite, it would be good practice to wipe down with alcohol to remove debris. The puddle is already having to offgas the coating as it burns off, so any additional contamination will hurt your efforts. Keeping the puddle molten for longer will give more time for the offgas to occur, but then you risk burning through.
Tri-gas mixes work very well when you're after all the corrosion resistance you can get with stainless, but for the hobbyist doing exhaust work, use 98/2 Ar/O2. Waaaay cheaper and it wets in pretty well for short-circuit transfer.
MoonRise is spot on. 70S-6 wire and any Ar/CO2 blend will do you fine. You can clean off the coating, but honestly, you can weld through it. Just be diligent in cleaning/brushing off the joint before you weld (contamination issue mentioned above). Re-coat after cleaning the welds to provide corrosion resistance.
Phew! I hope that was helpful for future reference.
ER308/L is best used for joining austenitic to austenitic (300 series to 300 series).
ER309/L has higher levels of Cr and Ni than 308. When the stainless and mild steel (or aluminized carbon steel) mix together in the weld pool, you create what's known as "additive mixture/admixture/admix". Admix is essentially the child chemistry of its two parents. The higher Cr and Ni from 309 provide the admix with the necessary corrosion resistance, ductility, high temp strength, etc. Moral of the story, when joining a carbon steel to stainless, use 309 if possible.
To the gent getting porosity with GTAW, the aluminum oxide layer varies in thickness based on the ASTM spec, anywhere from .25 mils to 1+. Depending on your cleaning method, it's entirely possible to smear and embed the coating into the base metal if you're using a grinding wheel. Even after using a tigerpaw or scotchbrite, it would be good practice to wipe down with alcohol to remove debris. The puddle is already having to offgas the coating as it burns off, so any additional contamination will hurt your efforts. Keeping the puddle molten for longer will give more time for the offgas to occur, but then you risk burning through.
Tri-gas mixes work very well when you're after all the corrosion resistance you can get with stainless, but for the hobbyist doing exhaust work, use 98/2 Ar/O2. Waaaay cheaper and it wets in pretty well for short-circuit transfer.
MoonRise is spot on. 70S-6 wire and any Ar/CO2 blend will do you fine. You can clean off the coating, but honestly, you can weld through it. Just be diligent in cleaning/brushing off the joint before you weld (contamination issue mentioned above). Re-coat after cleaning the welds to provide corrosion resistance.
Phew! I hope that was helpful for future reference.
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astroracer
Well-known member
Don't! Spend the money on having them JetHot coated! The wrap will destroy your pipes in a matter of a couple of years. JetHot will protect them for many years. I have a set of headers on my truck I had coated in 2000. 18 years ago. They are still rust free and looking good...
Mark
89GLH
Well-known member
^ Dammit, but then I have to make pretty welds.
Ohmthis
Well-known member
Get the joints really tight, set up the welder a little hot for the material thickness, and then weld spot welds around the pipe overlapping slightly. If the heat is right you will have a mostly flat weld. How did you plan to weld these? Short stringer welds? Start and weld 1/4 of the pipe at a time?
89GLH
Well-known member
Yeah, short stringers after tacking it up.