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frankcc
08-07-2004, 10:16 AM
Anybody,
When I am making the root run on steel pipe I get porosity in the starts. Root runs on stainless pipe are no problem to me because I use argon backing. Argon backing is not required on carbon steel. Welding the root runs on steel are a lot harder for me to do. I would like to know if there is a way to have porosity free welds all the time that will pass xray.

Frank C C

Rocky D
08-07-2004, 02:25 PM
Welcome to the forum. Frank....there's lots of intel here that can help. Porosity is typical in steel pipe when there's not enough filler rod going into the puddle, or the sheilding gas may be to high or too low. What size pipe are we talking about? What type of steel? What filler?

MACH4
08-07-2004, 07:01 PM
Anybody,
When I am making the root run on steel pipe I get porosity in the starts. Root runs on stainless pipe are no problem to me because I use argon backing. Argon backing is not required on carbon steel. Welding the root runs on steel are a lot harder for me to do. I would like to know if there is a way to have porosity free welds all the time that will pass xray.

Frank C C
Frank,
I have also had this problem on carbon tig and have had very good luck by using a scotch brite pad on my filler rod to clean it and to also use flap disc on the area that I'm going to tig. It's almost like welding Al. i.e. the cleaner the better!!! Hope this helps in some way. Let the board know how you do on this process, what makes your weld better!!
Mike
MACH4

frankcc
08-08-2004, 07:57 AM
Welcome to the forum. Frank....there's lots of intel here that can help. Porosity is typical in steel pipe when there's not enough filler rod going into the puddle, or the sheilding gas may be to high or too low. What size pipe are we talking about? What type of steel? What filler?

Hi Rocky,
2'" sch 40 pipe seems to have a tendency to be hard to penetrate and be free of porosity. For 2" I have been using 1\16" ER 70S6 wire for position welding. Larger size pipe I use 3\32" wire. Shielding gas is around 15 cfh. I use a 3\32" tungsten and pipe is A106. I seem to have my problems in the starts. Any Help you or anyone out there can give me would be greatly appreciated.

Thanks,
Frank C C

Rocky D
08-08-2004, 11:03 AM
Hi Rocky,
2'" sch 40 pipe seems to have a tendency to be hard to penetrate and be free of porosity. For 2" I have been using 1\16" ER 70S6 wire for position welding. Larger size pipe I use 3\32" wire. Shielding gas is around 15 cfh. I use a 3\32" tungsten and pipe is A106. I seem to have my problems in the starts. Any Help you or anyone out there can give me would be greatly appreciated.

Thanks,
Frank C C
I would use the larger wire, and gas at 20 to 25 cfh..also a torch outfitted with a gas screen lens on it.