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Hey guys have done alot of reading on this wire and the issue im having but have found so many different answers. So i figured i would just ask about my situation. Ok so i have a 252 millermatic, i upgraded the handle and lead to a 300 amp bernard. I run 75/25 ar co2. I am having problems with the weld cracking in the center, Its random. It happens sometimes on thinner metal (such as 3/8) or thicker metal when im doing a 1" flange to 3/8 steel. Now with the thicker 1inch flange i do preheat before i weld. Just yesterday i was welding 3/8steel to 1/4steel would lay a very nice bead then the next would have a crack down the center. I just dont get this inconstancy. I am welding inside my shop, have one of the door open but no wind is blowing. My volts for the 1inch flange to 3/8plate around 24.3v 380ipm. My gas flow is 25cfm. From what i can tell its hot cracking mostly. I just don't know sometimes i think its just cracks when i do small welds like 2inch long. but im not sure. no pics right now when i get home i could see if i find and cracks that i haven't already ground and re-welded. Any points or help would be great. thanks
Reply:Longitudinal (centerline) cracking, possible causes:- joint restraint- improper bead shape (too deep and narrow, concave)- high carbon content- low melting point contaminants (lead, sulphur, phosphorous)- hydrogen pickup- too rapid cooling rate (use more preheat and possible postheat)Your listed voltage seems a bit too low. ESAB data sheet suggests more like 25.5-28.5V for 0.045 7100Ultra using CO2 (192 amps @ 25.5V and 300 ipm WFS, 230 amps @ 27V and 400 ipm WFS, and 275 amps @ 28.5V and 500 ipm WFS ). If you are using C25, then that could be the voltage difference though, as voltage with C25 is usually 1-2V lower than pure CO2. The best laid schemes ... Gang oft agley ...
Reply:Yea i was justs looking at their website and also doing some reading they have up. I have never run pure co2 and i see you can run the ar and co2 but they don't give you setting for it.
Reply:I was just running some and noticed that I'm running 26.7 volts with about 320 wire feed pure CO2 at 40cfh. I'm using a XMT304 and a RC12 suitcase. The wire feed is just a guess since this one doesn't have digital and there's likely a little voltage drop with the 25' lead to the suitcase. I've never tried it with my 252. I'm not sure it's really up to the job for the 0.045" stuff. I know I run about 230 amps at the setting I'm using above and up to 260 amps with the higher setting I sometimes use for heavy stuff (1 1/2" and thicker). I've not had much luck turning this wire down very low myself but I have run it at 300ipm and about 25.8 or so volts before which is as low as I can get it to run properly.Last edited by irish fixit; 04-22-2013 at 01:09 PM.Millermatic 252XMT 304'sDynasty 280DXHypertherm PowerMax 1250Miller Trailblazer 302 EFIOptima PulserXR feeder and XR Edge gun and more athttp://members.dslextreme.com/users/waynecook/index.htm
Reply:OK so think i should mess with setting a little? Maybe better technique? I just dont understand the inconsistencies |
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发表于 2021-8-31 22:48:31