TIG welding Carbon steel - Page 2

mysterio · 11-08-2009, 12:45 PM

What have I started?

..Anyway, today, you'll all be happy to hear, I'm off to get some proper filler rods.

Sonex522 · 11-08-2009, 05:28 PM

Quote:

Originally Posted by Strong Bad

Please provide linky to the referenced scientific study, I would love to browse trough it. Esp the part about normalizing/stress relieving or otherwise heat treating the weldments. I'm not so contrary, but I do seem to share a popular opinion.

http://www.lincolnelectric.com/knowl...hrome-moly.asp

I started to suspect these things on my own after doing testing to destruction after welding 4130 tubes together with my MIG welder. I sat through a Lincoln welding forum at Airventure where they discussed the testing they did in depth. It involved welding thin section coupons together and testing them for strength and fatigue resistance. TIG welding beat all other methods, and they found that any sort of heat treatment that would result in positive results would be near impossible to accomplish in one's garage with a torch.

Sonex522 · 11-08-2009, 05:41 PM

If you want to do a neat test, make a square out of 1/2" 4130 tubing, miter cut and welded at each corner. MIG weld it, then cut one leg. Not much happens. Now weld the cut leg back, "heat treat" the corners and cut a leg again.

Bang. It's a whole different ball game.

I've welded cluster joints together and tried to break them by bending on tubes, smashing with a sledge, etc. What always happens when you grab a tube and reef on it is the welded joint is not fazed and simply bends the adjacent tube material.
The only time I've been able to make a brittle weld that would break adjacent the heat affected zone is when I deliberately over heated the joint when oxyacetylene welding. When that tube snaps like a piece of chalk, all the book reading and internet arguing goes right out the window.

With TIG, I think a temptation arises where people want to minimize filler rod use and make teeny little weld beads because they look neat, but otherwise, I think it's the way to go.

11-08-2009, 12:45 PM	#16
mysterio Eventually an Adventurer. Joined: Aug 2007 Location: Sydney: Black tracks and concrete canyons Oddometer: 967	What have I started? ..Anyway, today, you'll all be happy to hear, I'm off to get some proper filler rods. __________________ "This is the way the world ends/Not with a bang but a whimper." T.S. Elliot. "This is the way the world ends/ Not with a whim but a banker." Paul Desmond .

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11-08-2009, 05:41 PM	#18
Sonex522 zipper suited sun god Joined: Mar 2006 Location: Eastern Wisconsin Oddometer: 955	If you want to do a neat test, make a square out of 1/2" 4130 tubing, miter cut and welded at each corner. MIG weld it, then cut one leg. Not much happens. Now weld the cut leg back, "heat treat" the corners and cut a leg again. Bang. It's a whole different ball game. I've welded cluster joints together and tried to break them by bending on tubes, smashing with a sledge, etc. What always happens when you grab a tube and reef on it is the welded joint is not fazed and simply bends the adjacent tube material. The only time I've been able to make a brittle weld that would break adjacent the heat affected zone is when I deliberately over heated the joint when oxyacetylene welding. When that tube snaps like a piece of chalk, all the book reading and internet arguing goes right out the window. With TIG, I think a temptation arises where people want to minimize filler rod use and make teeny little weld beads because they look neat, but otherwise, I think it's the way to go.