I'm having difficulty with 3cr12 stainless fillets 1/8"thick

By Kix

Date 06-19-2008 14:11

My problem is penetration and fusion with short circuit transfer on 1/8" 3cr12 stainless using .035" 308lsi wire. We're using 2 different gasses ( trimix 90%helium-7.5%argon-2.5%co2) and (98/2 98%argon-2%co2). Penetration profiles between the two gasses are very similar with incosistent penetration to the root and lack of fusion outside on the legs. Positions are 2F, 3F vertical down, and 4F. I got the 2F and 4F to pass barely and the vertical down is giving me hell.
Parameter for Trimix are ruffly 22.0v and 290-300 IPM somewhere around 150 amps. Parameters for the 98/2 are 18.5v -19.0v 350 IPM. Note the IPM changes between the two gasses. This was done with 2 different Miller 350p's and both have supposively been calibrated. I don't know if this is a characteristic of the base material because of how hard it is or what. Any tips or tricks or comments welcome!

Thanks, Ray C.

By Lawrence (*****)

Date 06-19-2008 19:49

Jettison the short circuit and put a roll of 0.045 on your 350P and pulse it. (that's right 0.045~~ you will find that it pulses better than 0.035)

The 350P will make GMAWP fillets with 0.045 wire in stainless sheet in all positions with no burn thru easily on stainless sheet down to 1/16th and even a bit thinner with practice.

Furthermore you will be able to ditch the over spendy tri-mix gas and go with 2% O2 or C02.

Ray I bet you already anticipated this response from me diddn't you?

By GRoberts (***)

Date 06-19-2008 20:09

Lawrence,
We are butt splicing 16 & 18 gage stainless sheet with pulse- at 80 IPM travel speed. It work great and keeps the distortion down. We are using .035" wire though.

By Kix

Date 06-20-2008 12:20

You bet I had a good Idea what your fix was going to be.;-) My delema is that out of 30 guys welding, 3 350p's on the cab/body line, and 3 guys that absolutely refuse to pulse, I have to develope procedures for this process. Every time I show them how good pulse runs and get them all set up for it, I come back the next day and they're back to straight mig. The reason I have to quallify this procedure is because the majority of our machines do not have pulse capability. I am also currently fasing out the trimix because I can't have 30 welders come crying to me all at one time ya know.;-) Have you actually done macro's on 1/8" stainless using .045 pulse? I'm also feeling I would get better results on 304L base material then I would on 3cr12.

By GRoberts (***)

Date 06-20-2008 13:26

No, I haven't done any macros, only break tests. As for the stainless steel, we were using 304L as well.

I know what you mean about welders not wanting to get with the program. We have a few that do the same sort of thing when it comes to aluminum. We need to get some power sources that lock them out of the CV mode for some applications.

By GRoberts (***)

Date 06-19-2008 20:07

I was about to post the same thing as Lawrence, but lost my internet connection. We had the same problems on 11 gage until we switched to pulse. We also weld the 11 gage uphill, it can take the heat. The only sheet we use short-circuit on now is 18 gage and thinner (and downhill of course).