Welding Stainless Pipe with Mig

Date 02-17-2004 03:44

Today at work I was hit up with a question from the foreman at the shop, The owner has a job with a bunch of 2 inch schedule 10 304 stainless, and he wants some prefab work done, and he wants it to be welded out
on the roller in one pass using Mig and wants good pen., we have a Lincoln STT machine using 035 stainless (308lsf8) wire and trimix. The lines are to be low psi water lines.

Can't use tig, or back up rings, or any type of purge.

I know this sounds crazy but just wondered if anyone has done this before and has been successful, if you have I would like to know parameters and fit up. The foreman has tried a few practice pieces and it doesn't look like he is having much luck. Hope I have given enough info. Have a great day everyone!

By dee

Date 02-17-2004 04:35

This is out of my field, but I sense a bit of urgency in the issue.

I didnt read you tried painting the inside of the connections with any kind of flux. There is a brush on material available for that purpose where purge, etc, is impossible; I've no experience with it but it might be worth a look-see.

What's going on wrong with the results the boss is getting? My ghuru for all matters metal would probably suggest a two part gas mix of Ar/3% CO2 or thereabouts, but he takes telephone calls when it's urgent- try his link:
http://www.weldreality.com

I would gamble the answer will lie in there somewhere. Look through consumables section first?

Good luck
d

By TimGary (****)

Date 02-17-2004 12:20

I like to use 98% Argon and 2% Oxygen when GMAW SS.
It helps with penetration and wetting along the toes of the weld.

Good Luck
Tim

By jwright650 (*****)

Date 02-17-2004 14:15

Any idea what grade of stainless you are working with? Some grades maybe fussier than others.
John Wright

By kam

Date 02-17-2004 15:25

I might be able to help but alittle more information is needed. As stated in the other posts please tell us the type of ss you are welding, the joint configuration, and the problems you are having with you current process. Also what is the thickness of the material? I'm not familiar with schedules.

Thanks

kam

By GRoberts (***)

Date 02-17-2004 15:42

Flour pioneered a no-backing gas process with GMAW. I learned about it at a Euroweld siminar. If you contact Eurweld, I'm sure they can get you further information. Apparently they can do it easier than GTAW with no backing gas.

Euroweld
Bill Newell
(704) 662-3993

By welder03 (*)

Date 03-04-2004 04:40

Hi

Thanks everyone for all of your input, I have edited my post I had the incorrect schedule of pipe on there, also we could use solar flux, on it, sorry about getting back so late I had to leave the shop for a while to go back out into the field, the type of joint we are using is a bevel with a 1/16 land and 3/32 root opening.

By thirdeye (***)

Date 03-04-2004 04:49

welder03

I've seen a couple of bids this year for refinery piping where the contractor proposed using solar flux. Is there any internal residue? If so how do you clean it?