Pulsed MIG on high alloy stainless

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Hey there all. I need some help with getting my machine set up to run ERNiCrMo -10 wire. It will be run on pulsed mig through an ESAB Aristo set up. The foreman's recommended settings arent very good, but this stuff is so hard to weld with... I dont understand the pulse parameters very well, so it makes setting the machine quite frustraiting. It will be fillet welded on 316L of varying thickness for now, AL6XN and 254SMO in the future. 3/8 will be the biggest weld size, all will be done on tank rolls. This weld is connecting the shear ring to the shell. 150" or so on the o.d. its gonna be a long one lol... all technical info can be provided. Thank you
Reply:What are you running for a gas mix?
Reply:Straight argon, just as the procedure calls for. i think at 40 cfh. some guys have had success with adding a hair of nitrogen. I dont think gas is the issue, its understanding pulse parameters and how to use them. Especially once the tank is rolling. I feel that plays a huge part in it
Reply:Gas has a significant impact on pulsed GMAW with nickel alloys, duplex steels, and a number of others.  The various equipment manufacturers generate baseline wave forms with the power supplies, often dependent on filler metal diameters and an assumed gas mix.  Deviating from the recommended gas mixtures can radically alter arc characteristics, and can often drive the user to have to run excessively high voltages to eliminate spatter and have a usable bead profile.  Unfortunately, this also results in excessive heat inputs, which is contradictory to the reasons for using pulsed GMAW to begin with.So, my suggestions would be:a) contact ESAB to determine which waveform preset is intended for your filler metal classification and diameter'b) verify that you're using an appropriate gas mixture.  Almost all of my experience with nickel based fillers and GMAW-P is that they run like crap without an Ar/He/CO2 mix.  c) disable all of the "specialty" controls, and dial in your arc with voltage adjustments.
Reply:You have some great info. Ill give the tri-mix a shot, as well as the bit of nitrogen. Arc stabilization was the reason for nitrogen in the first place. Results will be posted on this thread after work tonight. Also ill see what esab has to say about the filler. This stuff is so sensitive to any change in setting you make, even with synergic mode turned off. Those aristos are extremely nice machines id like to get the most out of it. Pulse frequency, time, background current, Ka. All of these parameters are what's got me confused. Do you know what they do the arc and characteristics of the weld?
Reply:Higher pulse frequency and lower background current give you a narrower arc, deeper penetration, and a higher narrower bead. The reverse is also true. I have no experience with ESAB equipment so I can't comment on the settings.I second Supe's recommendation on the gas. Most pulse MIG welding of high-nickel alloys is done with argon or argon/helium mixes with a small amount (1 - 2%) of CO2 or hydrogen.JohnA few weldersA lot of hammersA whole lot of C-clamps
Reply:Ok so no results tonight guys I'm sorry. I got busy working on some other stuff and was elected to be the pipesnake as usual. I'm gonna give the tri mix a shot tomorrow and adjust the machine accordingly and see what kind of magic we can work. Unfortunately if it turns out good, I still wont be able to put it on the tank because of procedure and code ****. ASME is always so technical... maybe i will anyways nobody will know lol  regardless ill post the results and pics in a new thread so everyone can benefit from the info. Its hard to weld with and there's probably alot of guys out there pulling their hair out over it. Thank you again for the great info guys its going to help tremendously in dialing this ridiculous alloy. Funny thing is, it's no problem with other processes. It can be tricky with GTAW for some, because of its heavy dense puddle characteristics. But that's for another thread. Hope this helps everyone have a good night
Reply:If you see significant improvement with the tri mix, your company would be money ahead spending the money to weld up a new PQR coupon and qualify the procedure.  Unfortunately, unlike GTAW, while the adjustments can be made similar to GTAW to adjust the arc characteristics, there is a limitation to it.  The actual shape of the waveform, i.e. the shape of the up and down slopes, is controlled through the manufacturer's programming, so when you deviate outside of what they tailored the program to, you tend to have mixed results.  Far more too it than just controlling the width and frequency of the pulse.  I ran into that when developing a nickel overlay procedure for some boiler tubes.  I was locked into a 75/25 Ar/He mix, and thankfully, it didn't have to look pretty...
Reply:I'll add a third recommendation for tri-mix when welding pulsed GMAW Ni-based or stainless steel fillers.  I've used higher Argon content mixes successfully, but I have been told that the high Helium mixes are good also; albeit much more expensive these days.I'll also second the recommendation for getting application specific settings from ESAB for your equipment.  I've seen this from Miller and the right pulse settings can make a big difference.  Your local welding salesman might not have the answers, so be persistent in getting back to a specialist at ESAB if the local rep isn't an expert in pulsed GMAW.Supe, have you seen Ed Craig's photos of overlay procedures on boiler tubes.  I'm not sure if I'd drink his brand of Kool-Aid or not.  But Ed Craig says those nickel overlays don't have be ugly at all.  Maybe start another topic if you want to discuss?Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:That's a huge part of my problem with this stuff. It has to look good on top of being a good weld. The customer is etremely picky about procedure because its oil refinery stuff and for that particular vessel tri mix is out of the question. With the settings I use with straight argon, one could lay a very nice fillet manually. But that will not work on roundabout fillets on the rolls for some reason. Could that be a direct result of argon's density? A far more experienced mechanic than i told me it can "fall off" the weld depending on position. Maybe that could account for the instability of the arc as well? I will also.post a comparison pic of the welds done with both gasses
Reply:Originally Posted by A_DAB_will_doI'll add a third recommendation for tri-mix when welding pulsed GMAW Ni-based or stainless steel fillers.  I've used higher Argon content mixes successfully, but I have been told that the high Helium mixes are good also; albeit much more expensive these days.I'll also second the recommendation for getting application specific settings from ESAB for your equipment.  I've seen this from Miller and the right pulse settings can make a big difference.  Your local welding salesman might not have the answers, so be persistent in getting back to a specialist at ESAB if the local rep isn't an expert in pulsed GMAW.Supe, have you seen Ed Craig's photos of overlay procedures on boiler tubes.  I'm not sure if I'd drink his brand of Kool-Aid or not.  But Ed Craig says those nickel overlays don't have be ugly at all.  Maybe start another topic if you want to discuss?
Reply:I am afraid I have to disagree, especialy for the refinery. Procedures are usally developed by welding engineers  and are tested.  Before I started changeing gas mixtures, which can affect certified welds I would check with my employer, the liability issue is huge. In  Pulse mig welding WFS is crucial to arc consistency, the precedures should call for a specific volt/amp setting.  Make sure your Esab is there and then double check recess and ESO.
Reply:The customer is the one who defined the procedures, they are extremely picky and we are absolutely not allowed to deviate from it. Liability and ASME go hand in hand especially for big name customers like GE Ionics. Besides that I will still be posting a thread once I get some welds done so guys who are struggling with this filler and process will have some guidance and pics to compare. The info you all have provided about the gas mixes and pulse currents is invaluable and is gonna go a long ways with helping out the ones who are new to Nickel alloys and their sensitivity. Id love your input once I get the next thread done with pics
Reply:If that is a question then the answer is yes. Like 2% or so. They say it stabilizes the arc. I have not tried this so I can't confirm nor deny this claim
Reply:No, it's just a @#$%! spammer. Notice how he just regurgitated text from your post #3. The administrators recommend that you report them but do not respond to them. Hopefully they will crawl back under their rock and stop bothering us!A few weldersA lot of hammersA whole lot of C-clamps