Heating duplex weld joint by TIG arc welding

[Karik87]

Hi experts,
The welder has just completed a weld on a Duplex stainless steel pipe (A790 UNS S31803). After welding, He noticed a significant misalignment between the tee and the pipe — clearly, the joint has distorted more than expected.

To correct this, he applied TIG arc heat onto the cap layer of the weld in an attempt to realign the components. No filler was added — he simply used the arc to locally reheat and relieve stress in the distorted area.

My question is:
Is this practice acceptable for duplex stainless steel welds?
Are there any risks to mechanical properties or corrosion resistance from using TIG arc for distortion correction like this?
Is this prohibited or discouraged in any applicable welding or metallurgical guidelines?

I understand that duplex materials are sensitive to heat input and thermal cycles, so I’m concerned this may affect the phase balance or introduce unwanted microstructural changes like intermetallics.
I’d really appreciate insights from others who have dealt with similar issues. Have you used this method before? Did you perform any tests (e.g., hardness, corrosion, microstructure) afterward?
Thanks in advance!

 

[r6155]

Some photo?
More info: dimensions, amount of misalignment............?

Where was the welding supervisor? .......

Is he a qualified welder?.Did the welder perform the repair without consulting anyone?

 

[EdStainless]

The duplex weld procedures that I have written would not allow this.
If the joint was cold when he did this and he didn't apply enough heat to get the inside of the pipe up to 600F then it might be nothing.
Or he could have just created a location that is loaded with intermetallics and as such has very poor ductility and terrible corrosion resistance.