In applying standard recommendations for GMAW 1/4” aluminum with 3/64” 5000 series filler wire I get a lot of incomplete weld fusion.
My question is, what wire speeds are actually being used in production welding 1/4” thick plates of 6061-T6 in T-joints with 1/4” fillet welds, using 3/64” 5356 and 5556 filler wires, and argon gas?
When I use a wire speed of 500 ipm at various voltages and are lengths, I get a lot of incomplete fusion with either 5356 or 5556 wires. When using 5356 wire I get good weld results at 650 ipm wire speed, 280 amps, and 24 volts, and with 5556 wire I get good weld results at 750 ipm, 280 amps, and 24 volts, which seems to be a lot higher than what is typically recommended.
If you have actual experience with welding fillets welds with 6061-T6 base metal and either 5356 or 5556 wire, please respond. Thank you.
You can not weld by meters alone they are not acurate enough on IPM,volts,amps.You can use them to get close then you must tune it in by sound and apperance and as the machine and cables heat up you will have to make adjustments.
R:
I have qualified on this material using GMAW (several times).
There are a number of issues that can result in IF or IJP on aluminum weldments:
1.) How is the material being prepared and cleaned? Mechanically, chemically, both, etc?
[Does IF occur on both members?]
[Clean part right before welding. Aluminum oxide begins to form immediately after removal.]
2.) Work/travel angles are very important for Al and not as forgiving as steel.
[Does IF occur on both members?]
3.) Pumping helium (Argon/Helium mix) into the shielding increases arc voltage and the penetration (weld) profile.
[Pure argon is sufficient, but the addition of helium can help.]
4.) Watch your electrode extension and arc length.
[Increase in the extension/arc length will lower arc voltage resulting in a decrease of penetration.]
5.) Ideally, you should be in the spray arc transfer mode. The sound will be more like a hissing sound with lttle to no spatter.
[What does the finished weld look like? Lots of spatter, ropey, black soot, etc.]
6.) Arc travel speed is also a consideration.
[Too fast will result in IF/IJP.]
7.) The numbers on your machine are just that, the numbers on your machine. You will experiance voltage drops through the leads, any faulty connections, etc.
[The best way to ascertain a true voltage reading is at the terminal block on the wire feeder.]
8.) Lincoln, ESAB and Alcotec have some very good info on the subject. You can download the info at no charge form their web sites. Alcotec has a great alumnum welding seminar.
Only noted a few items.
Let us know how you resolve the issue.
Only one thing I can think to add to the well thought out previous post is that you should always push the puddle when welding aluminum GMAW, this allows ionization of the oxidation to take place ahead of the weld.
Mike Sherman
hey rory,
i went to an alcotec aluminum seminar and it was great. the web site is www.alcotec.com the one thing i learned about mig alum. is cold starts. maybe some type of pre heat. i also learned preheat with a torch is bad because it produces h20 from combustion. alum doesnt like hydrogen. also the addition of helium might help. 280 amps should be enuff. go to alcotec.
rich
We have learned that when preheating Al with a torch, keep the heat until the base metal turns a sooty color, than continue until the color is gone. At that point all the moisture is gone.
Having said that, the thickness he referred to should be very easily welded with no preheat (as long as ambient is at or above 50 F).
Charles Hall
Beware of 3356 used in fillets for 6061T-6. It is sensitive to fractures from corrosion. Although it is strongest in a butt joint (and usually prefered in M.I.G. processes due to the fact that it is stiffer and therefore tends to feed without bending) it is not recommended for fillet welds.
Understand that I say this in regard to joints that are subjected to extreme abuse which require the utmost strength and quality (for a door jamb or the like, it probably wouldn't matter.
You have already gotten the best advice, which is to call altec. A phone call to a few welding supply shops would give you an 800 tech number for reference that is likely to provide the best advice of all.
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