The weld wire manufacturers indicate the recommended ranges for amps, volts, and wire feed speed, but I'd like to know based on your actual experiences what ranges some of you use on your wps's for fcaw process using .045 71m wire with 100% carbon dioxide welding anything from 1/4" thick up to 1 1/2" thick or so, in the spray transfer mode. I have heard that flux cored wires by their very nature will determine the transfer mode. Some flux cored wires will be globular and others will be spray. I want spray transfer, and I want to make sure my parameters and wire are correct so that I acheive this. Also, what about the same ranges for the gmaw process using .035 mig wire, a 98/2 argon mixture, welding 1/8" thick up to 1/2" or so, in the spray transfer mode.
We use 71M as our standard wire. Parameters depend on the work (D1.1, D1.5, maintenance, etc) but we do run 0.045 at 29V/260A with 100% CO2 for our D1.5 WPSs. That was the only way we could consistently get 5/16" 2F fillets in a single pass. That allows a fast enough travel to be able to stay in front of the puddle and will build to the correct size without holding back. Running lower than that would almost always result in no penetration to the root of the fillet. Those parameters pass fracture critical PQR requirements consistently as we have done for 10 years.
My understanding is that high percentages of Argon in the shielding gases is required to achieve spray transfer with FCAW or GMAW. High heat input FCAW appears to spray but is really globular transfer with very small particles. I am no expert on that subject so others may give you better info.
Chet Guilford
As for the spray you need stargon gas, 90%ar,8%co2,2%oxy, this will give the best shielding for spray transfer.
Forum
