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welding titanium questions


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I have an ongoing R&D project where i need to weld 24g titanium sheet metal to a 5/16 and/or a 3/8 titanium bolt...am getting lousy welds and seriously cracking welds around the heatzone.. Info i found online said the titanium needs to be mechanically cleaned and then chemically cleaned with acetone. am doing the welding in an enclosed box with a purge of argon.. any other tips or tricks that i should know before i mess up more of this thin gage stuff?? Thanks in advance!!

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? are you Tig or Mig welding these pieces -- metal MUST be clean ! -- if you,re Tig welding use a gas de-fusser collet set up
Ti doesn't like a fast cool down @ the end of the bead so come off welded heat slowly when tig welding -- weld bead colors Ti
has some of the most deep bright weld bead colors Ive ever seen !! when things are going right you get a Gold color -- next down
seams to be sliver -- NOW there's other colors you can get bright reds--blues--purples + now these colors MEAN something !!!
to much power or torch angle off - Ar gas problem - welding to fast or to slow - rod feed not right - so on ????? I have Tig welded allot of Ti years back -- AND have YET to find someone that knew what the colors MEAN I sure would like to know that still !!
anyway when it welds right looks right -- a good Gold colors seams to be what you're shooting for
I hope this helps some & if anyone out there know anything about the colors of Ti welding Idd like to here about it !
its a fun metal to weld - though it likes to crack @ the end of the bead so keep a little heat on the end & back up the weld bead some then come off of it GOOD LUCK Steves Welding

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Ti welding in not the art of welding but the art of purging! Gold is good for stainless but for Ti you do want, for the best weld, a bright shiny silver weld. The better the purge the better the weld. The colors will run from silver=best, straw=good/ok, dark blue=border line but ok, dull lighter blue=bad, chalky light blue=throw it away. I work in a major chemical plant and we weld TI on a very regular basis. (I've been welding it for the past 27+yrs) We use a trailer behind the torch head for about 3"-4" keeping a constant purge on the weld deposit. We weld open butt 1/2" schedule pipe with 100% X-Ray up to 24" open butt 100% X-Ray. All of the 'trailers' are made in house and fit each size pipe to ensure proper purge. We also have trailers for flat and fillet welds. Once past this area the weld is out of the critical stage and air won't hurt it. (once the weld has cooled enough to remove the purge you can dunk the part in ice cold water with no effect on the weld! amazing stuff!) BTW, the colors come with poor purging, either from bad argon or sucking air because your gas flow is too high. 3/8" and up don't need a back purge.

In your case, with a purge chamber, you may want to check your argon, flow rate, and seal of the chamber. I would also suggest using a filler as you can often concentrate your heat on the rod when needed. If you have a foot control or finger control ease out of the puddle slowly. Not only do you need to clean the parts but also the filler rod. Clean, new SS wire brush then wipe with acetone, with the rods you can just wipe with acetone. Also, use clean gloves.

If you take a sharp point, like the point of a pocket knife and drag the point across the weld and base material you can feel if you have a bad weld. If the point has a "drag" like the base material then Good! If it "skates" the weld is brittle and there is nothing you can do to TI to remove the brittleness. The weld will need to be cut out and at least 1/4" out side the HAZ. Have fun! Ti is probably my favorite metal to weld, it's easy if all is well and I like the challenge of makeing it all well!

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Guess i got lucky years ago. A friend brought me a burner housing from the company he worked for. It was to be used for roasting 55 gallon drums. It was made from .125" Ti, and it was formed into a cylinder about 4' tall, and about 2' in diameter. He also supplied the rod to weld it with. I had to weld a couple of cross braces across the top that were made of .250 x 2" flat stock. I just upped the flow on my flowmeter, and buzzed them on, then trimmed the excess off with an OA cutting torch. It welded extremely nice, and the welds looked like glass they were so smooth. I saw him a few yeas later, and asked if the welds held. He said that they had held up fine, but the cylinder was now distorted, and misshaped from the heat it was subjected to.

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