after reading through Ed's site, I,m looking into changing gases. Currently we use either 75/25 for short arc and flux, and the fancy wonder gas "AIRGAS GOLD" trimix (AR/CO2/HE) for spray transfer.Also, straight argon for gtaw. We weld mild steel (a-36, a-572, c 1018) with er70s-6 filler.
So my question is, do the other mixes like 92/8 or 85/15 really outperform what I'm using now, and can I use just one in place of all the others.
I know that there are alot of opinions out there, I'm eager to hear them all .
Also, if there are any aluminum users out there, I,d love to hear what you use for 6061 t6 with either 4043 or 5556 filler. gtaw and or gmaw
thank you for any and all info.
Nathan
Nathan
There are literally hundreds of posts on the forum board about aluminum and filler metal choices.... Aluminum choices are almost always based on service need or annodizing.
Unless your doing some fancy high speed robotic stuff and even then I doubt that the tri-mix can out perform a two part gas.
I'm not sure what exactly you mean by *outperform*....... Two part gasses can surely match depositon rates and depending on the surface condition of the steel you weld it may minimize the occurance of undercut.. If deposition rates are the same and weld profiles are the same than a two part gas for sure outperforms the tri-mix in cost annually.
Unless charpies required for lmpact reasons on your PQR's there are plenty of FCAW electrodes on the market that will run at very high deposition rates on straight CO2.... But many of those same electrodes can be used with a two part gas.... So you can weigh the simplicity of a single gas in the shop against the savings to be pocketed by using a two part gas for Short circuiting and Spray transfer GMAW and straight CO2 for FCAW... Of course these are all engineering level decisions rather than something based on internet chatroom advice :)
I use argon for steel & stainless TIG and aluminum MIG & TIG, 4043 & 5356. I don't do anything heavy enough to need a helium mix.
You should check the gas requirements of Your flux core G wire to see if it will meet mechanical properties with greater than 75% argon. some are formulated for pure CO2 to 25% CO2/75% argon, others for greater argon percentages.
I switched my whole facility to 85-15 for GMAW, 70s-6 .035, gave the transition to spray where we needed it and good short circuit sheet metal results. Flux core is a different beast and what holds true for solid wire doesn't hold true for FCAW.
for stainless we went to 98-2 (co2) from a tri-mix
you'll only see good results with any shielding gas change if first you have your process under control and have good parameters set. A lot of the times theres improvements to be had by simply looking at your process parameters and doing some welding training. Once your parameters are in line and your process is under control then you can start seeing what changes will reduce costs.
Thanks all,
I see that there is alot of research that still needs to be done. A little more info, as of now, 90% of our steel welding is either short, or spray. the other 10% being tig. FCAW is only done on a customer required basis, which is rare.Only 40% of our work is code work (d1.1), and all of that is prequal. We are in the live entertainment industry so there is a very wide range of fabrication that goes on, any thing from light gage tubing to heavy structural weldments. we sometimes switch between processes many times a day. I'm pretty much on my own to run the entire shop's welding program.right now I'm trying to streamline things, one of which is cost. the gas issue was just one of the things I was looking at. simply because the guy aren't going to switch out the tanks every time they change perameters. So what ends up happening, is that we go through alot more trimix than we should since that works for both.If you knew the shop, it would make alot more sense
I thank you all for your comments and continue to welcome new ones, as there is a whole lot more I need to learn.
Nathan
maybe look into a bulk system and you can vary your mixtures your self from pure co2 to pure argon. depending on the size of your shop it could introduce great savings
just a thought.
I have tried many things for MIG stainless and find nothing as satisfactory as dropping it in place of Heliarc. That said, I like the helium mix with mig. I don't get the color I like with a two part gas. As for spray on mild steel, I've gone back to 75/25 after every other experiment because it works just as well, and then I can stock one gas for spray and for short-arc (Lincoln L-56 for both).
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