Re: [MW:32377] RE: Black spots on DSS Weld Joints.

Good Morning,

1. Rub the wire with Emery paper and clean with acetone.

2.Keep the torch in approx 50 to 65 degree angle through which proper shielding can be created.

3.This will reduce  black spot remaining can be removed by polishing.

Thanks.

On 17-May-2021, at 9:45 AM, pgoswami@rogers.com wrote:



Hello,

 

Please see my responses to this old post (2104) in materials-welding forum as below.. These spots may occur:-

• Due to wire drawing residues (often very microscopic) in the filler wires. Rubbing with emery papers and acetones may clear some of these residues.
• Traces of cleaning products left on the Duplex base metals, called smuts .
• These dark spots may be removed by power brushing with stainless steel brushes or soft abrasive(Aluminized)  grinding tools.

 

You may see the attachment for additional guidance.

 

Thanks.

 

Pradip Goswami.P.Eng, IWE.

Independent  & Consulting Welding & Metallurgical Specialist

Linkedin: https://www.linkedin.com/in/pradip-goswami-2999855/

Email:pgoswami@rogers.com,pradip.goswami@gmail.com

Cell/Whasapp:1-905-9793232

 

Black spots on DSS Weld Joints. (google.com)

 

From: rajesh...@gmail.com <rajeshreddy32@gmail.com>
Sent: May 15, 2021 6:09 AM
To: Materials & Welding <materials-welding@googlegroups.com>
Subject: Re: Black spots on DSS Weld Joints.

 

Hi All,

 

We are also facing the same issue in SDSS welds on 6" Pipe welded with ER2594.

 

Can anybody let me know the root cause for this spots and remedy. 

On Wednesday, February 12, 2014 at 3:08:50 PM UTC+5:30 Vasantharao wrote:

Dear Experts,

 

We observe Dark spots on Welding of Duplex Stainless Welds.  

 

Material is : UNS S31803 ,  Filler Wire for root - ER2594, rest ER2209.

 

Sample pictures are attached for reference.

 

Oxygen level in shielding / Purging maintained well below 0.2%.

 

Interpass <150 Deg.C

 

Pl. share your valuable information.

 

Thank you.

 

P.Rao

Virus-free. www.avg.com

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