some TIG pictures

[eric75]

Just found this forum, it looks pretty informative.

About a year and a half ago I started getting very interested in welding. After a slow start I'm now doing roll cages for the school as an extra curricular activity. Thought you guys would like to see what we do.

A little feedback would also be helpful as I'm always trying to improve my skills. I actually have no formal training, just looking at books and other welds.

Most of the welds you see are on 1.25" OD x .049 wall 1018 steel tubing. Usually I use a 1/16" 2% tungsten with gas lens. About 80-100 amps depending on the fit up. The machines (that the school purchased) are Lincoln precision tig 275 and a Lincoln square wave 175. er70s-6 is the fill rod.
________
Nexium Lawyer

[Alex]

eric,
The weld in the first pic looks a little on the cold side to me. Doesn't appear that the toes are tied-in too well. Maybe a bit more heat next time.

Be cool,
Alex

[dyn88]

I agree with alex although the haz seems large. more heat faster travel! all in all a good job though. Have you tried any destructive testing before risking lives?

[eric75]

roll cage weld testing

Early on I did some section cuts of a few of my welds (for a class project). The sample I attached is straight splice of .083 wall 4130 tubing. Learned a big lesson about penetration then, but it is still cool to see the grain structure.

Since then It's been a lot of practice with coupons (same thickness as tubing) so I could inspect the backside for adequate penetration.

Some day I would like to try the "airframe welders" test cluster (tee joint with two 45 degree branches and plate slotted into the center). I would either section it myself or even try to get the certification.

As far a destructive testing on roll cage style welds, no. Do you have any good ones to recommend?

We have destroyed some suspension parts of the car you see in the picture. The welds there held up fine but the 1"od x .065 wall 4130 tube buckled under a bending stress caused by repeated hard landings.
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Roasting food

[Revlimit]

Looks alot like the SAE Mini-Baja car we build down here at the University of Florida. For just picking it up, and with your lack of "seat-time", your welds are above par. Is welding cool or what? I've been fortunate enough to spend time in the fiberglass/carbon-fiber industry so I'm able to fabricate with some of the really cutting-edge aerospace materials. That's been really rewarding, but adding the ability to weld has been awesome. There is so much to know about proper techniques! Anyway, I don't get to spend alot of time with Mini-Baja, as I work primarily on the Formula car. We are actually going to make the competition in Australia this year, so that's been exciting. None of it happens without a welder though. Good Luck.......Rev

[cleaver]

I agree with alex although the haz seems large. more heat faster travel! all in all a good job though. Have you tried any destructive testing before risking lives?

stupid question...but I keep hearing this "haz" word...what is it?



thanks...

[HAWK]

cleaver,

Did you get an answer on HAZ? Heat affected zone. The area of the base metal adjacent to the weld most heavily affected buy the heat of the arc.

[Caliber]

Can you guys working on the SAE projects, post a link to the SAE web site?
I had it one time, interesting site, others members might be interested in it.
TIA,
Rich

[cleaver]

cleaver,

Did you get an answer on HAZ? Heat affected zone. The area of the base metal adjacent to the weld most heavily affected buy the heat of the arc.

no..I didnt get an answer regarding HAZ...but you answered it for me! thanks again...

[Blown S-10]

HAZ is most noted by the coloration around the weld.

i wonder what HAZ aluminum has ?

[HAWK]

Blown S-10,

What HAZ aluminum has. There is a book to write on this. Here are a few basics. Yes, aluminum has a HAZ. It can be affected by tungsten size, arc frequency, arc balance, etc. It may also be affected by the type of aluminum alloy: Aluminum can be alloyed with many elements to produce a specific series of aluminum alloy. Further complicating the situation is the heat treatability of certain al alloys.

There is a lot written on this subject which may consume many hours of reading and re-reading to fully comprehend the material. I think it will suffice to say that most aluminum welds are not as strong as their parent metals in regard to the temper of the HAZ.

[Blown S-10]

i do know, first hand, that aluminum can be anealed and hardend.

[HAWK]

Blown S-10,

Correct. Certain alloys can be post weld processed. That is why a good weld engineer is a valuable asset when it comes to designing structural aluminum fabrications.

[HAWK]

Can you guys working on the SAE projects, post a link to the SAE web site?
I had it one time, interesting site, others members might be interested in it.
TIA,
Rich

I AM NOT SURE IF THIS IS WHAT YOU WANT?

http://www.sae-a.com.au/fsae/

[HAWK]

Can you guys working on the SAE projects, post a link to the SAE web site?
I had it one time, interesting site, others members might be interested in it.
TIA,
Rich

I AM NOT SURE IF THIS IS WHAT YOU WANT?

http://motorsports.sae.org/