SS heat distortion what can I do?

[Noods]

Hi
Was making a luvly job of tigging a piece of 3mm walled SS tube to a piece of 3mm SS flat sheet..

Ran min heat I could to get a puddle etc and ran the bead as fast as I could.. tacked first in 10 places around the tube and ran Tig beads in small runs before going opposite and running one there eg to move the heat around by not doing run in one go...

Flat sheet was clamped down on steel worktop but the sheet, not the tube, had warped all over the place...

Is there anymore I could do to overcome this pls... chill bars? Perhaps ...

Many thanks

 

[backpurge]

Heat sinks should help along with using back stepping technique but it is always a problem with stainless due to how the heat dissapaites

 

[Noods]

Heat sinks should help along with using back stepping technique but it is always a problem with stainless due to how the heat dissapaites

Is there anyway of straightening SS when it’s distorted that you know of?

 

[Brad93]

Is there anyway of straightening SS when it’s distorted that you know of?

Hammer and dolly

 

[backpurge]

I've seen distorted stainless straightened by applying heat spots using a TIG torch, very effective but believe me it is a black art

 

[Richard.]

Technique will help quite a lot.
A fillet joint round a 3mm walled tube will need up and beyond 110-120 amps. This will get things flowing very quickly and allow you to bomb round it at a decent rate thus reducing localised heat input.
Clamp it to something thick and conductive. Copper been the absolute best for this but a chunk of thick aluminium will also prove very useful at sucking the heat out of the stainless. If it’s sucking it out well you’ll know because it will slow you down and in which case you’ll need more current because speed is key.
You could also try a fast pulse to help you pick up the travel. By fast I’m talking 200hz plus. Bang 200 amps on the top and 50 amps on the bottom over a 50% duty and this will give you an average current level of 125amps. The high spikes allow you to increase your speed and the low spikes prevent you blowing a big hole through it. Again pulse reduces heat input and in turn reduces distortion. Give these things a try see if it makes a difference.

 

[Richard.]

This is the joint I assume.
This was performed by Derek on my most recent tuition session. 2mm tube to 1.5 plate. Welded at around 70-75 amps
Heat was sucked out by a big lump of cast iron. It’s lifted a bit but distortion is quite minimal

 

[Noods]

This is the joint I assume.
This was performed by Derek on my most recent tuition session. 2mm tube to 1.5 plate. Welded at around 70-75 amps
Heat was sucked out by a big lump of cast iron. It’s lifted a bit but distortion is quite minimal

That’s the boy mte... x