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Re: [MW:35898] Black Spots on DSS Welding

By Materials & Welding
This issue called Heat tint. Try to cool rapid or clean picking and passivation method 

On Thu, 13 Nov 2025, 3:18 pm Babur Khan, <mbabur.bwp@gmail.com> wrote:
Greetings,
We faced same issue, we did Radiography and surface examinations. 
Possible root causes are shielding gas during welding.
Muhammad Babur Khan
Sent from my iPhone

On 13 Nov 2025, at 3:07 PM, patni engineers <patniengineers@gmail.com> wrote:


Slag no weld surface
Clean Each weld pass by Ss wire brush.
Check filler wire properties
Use UHP ( high pure argon gas as shielding Gas)

Regards,

Chandrakant
B.E Mech.
ASNT Level II RT/UT/PT/MPT/CSWIP

GST -27AMOPP5962A1ZS
Patni Engineers. Mumbai. India
PED/2014/68/EU
welding shop AD2000/DIN EN ISO 3834
IBR Approved 

Factory Addreess- Pl Call 

On Thu, 13 Nov 2025, 15:22 Mahmood Alhinai, <mahmood.m.alhinai@gmail.com> wrote:
Dear Experts,

Kindly, refer attached photos and clarify what could be the reason of block spots appeared throughout DSS welding surface.

 the welding was carried out as per the approved WPS and approved welder, the DSS filler wire was approved (Bohler / ER2594 / ER2209). Pipe material: A790 UNS 31803
Welding process: GTAW

Thanks & Regards,
Mahmood

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