Titanium weld cracking

[Tsah]

hi, I new Here
I have problem and maybe you are can help me with it..
I was tray weld titanum gr2, the weld locking good and brilliant but if I try push it is cracked.
Thanks and sorry about my English
Photos:

 

[AndersK]

Looking at the color close to the weld I would guess you didnt have enough gas shielding. Silver what you shouls aim for. Straw or shiny blue is ok but blue, purple and dark yellow is not.

Titanium must be shielded a lot longer after it stops glowing, down to 300 degree C.

Also the heat tint so far away indicate you are welding too slow, heating up too large area.

There are people with much more knowledge in titanium than me that I hope chime in.

 

[Tsah]

Thanks!
I try it
What is the amper suggested?

 

[AndersK]

What thickness of material and filler?

Roughly 150A for 5-6 mm and 2,4 mm rod.

 

[Jim Davey]

Too much heat and poor shielding, you will need to adjust your amperage to allow for the fact that the pieces to be welded although fairly thick are quite small, sot they will overheat fast.

 

[backpurge]

As said above, insuffient shielding, heat input is far too high. The weld bead Lao looks quite large, try building the weld size up with smaller beads of weld rather than one big "lump" of weld which may not have satisfactory root fusion.
Just grinding the weld out and re welding may not sort the problem as the parent material could be adversely effected by the high heat input from previously applied welds. Best of luck with this job

 

[rikrobson]

does Ti not need flood shielding?

 

[backpurge]

does Ti not need flood shielding?

Depends on the component and its intended use, quite often just ensuring the shielding is adequate to keep the oxidising tints to a "straw" colour will do whereas some components need to be welded in a chamber to ensure they are tint free, it's horses for courses

 

[Tsah]

What thickness of material and filler?

This weld 10mm and 4mm with 1.6mn rod


i try some things today, the best welds was when I pre flow 3s and after flow 10s.

I think the problem was like you said,
Hover heating and less argon.

Thanks

 

[Tsah]

The 2.5-3mm welding look fine, the color silver and I don't hear the cracking..

 

[backpurge]

That's looking better, try and keep the weld size down, are you purging the inside of the pipes

 

[rikrobson]

That's looking nice what is it for? Is Ti better than ss for your purpose?

 

[Tsah]

I try next week weld with buck up argon for the inside.

It is manifold for a race car, userly I'm use in ss.
I want try make one from Ti because then I can down the thickness wall save weight and better flow.

This manifold I make from ss:

 

[slim_boy_fat]

Welcome to the forum, Tsah

That's impressive!! Tell us more about the car, please.

 

[Tsah]

Thanks
The Ti manifold go to Peugeot 205gti with 3.6l Audi Q7 engine,
The original engine came with 300hp and after the upgrade it's will be 900hp~

 

[Brad93]

Too much heat, not enough coverage on that titanium header. Have you purged the inside with argon? Sorry to say but when that gets hot and has some vibration through it thats gonna crack.

Looking at your stainless manifold I'm guessing your fitup isn't helping you. Trying to bridge gaps with Ti is not wise.

 

[Tsah]

The ss manifold is for other project, I want try work with Titanium because it herd and light, I think it's good for turbo manifold.
But thanks!!

 

[Brad93]

You know what I just spent the time typing out a long reply, but then thought why should I share knowledge I've spent a lot of time acquiring when you reply with that attitude, soldier on. I hope your manifold breaks on its first outing.
All the best.

 

[Tsah]

Sorry friend my English is not very good
I don't understand what is the problem
I explain you way I do it and thank you for your explanation

 

[Kent]

I try next week weld with buck up argon for the inside.

It is manifold for a race car, userly I'm use in ss.
I want try make one from Ti because then I
can down the thickness wall save weight and better flow.

This manifold I make from ss:

Reading what you stuffed into the car I can see why is so crammed on those pipes