Worm track/hole

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Kannayeram Gnanapandithan

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Aug 6, 2016, 10:40:58 PM8/6/16
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Process FCAW, Wire E81T1-B2/Dia 1.2mm, shielding 85%Ar+15%Co2. Flow rate 20lpm. Current 240amps, 26 volt, travel speed 800mm/ minute.    while welding, we are getting defect of wormholes/wormstracks , some time continuous and intermittent on top of the weld. Experts, what would be the reason for this defect?

pgoswami

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Aug 6, 2016, 11:12:41 PM8/6/16
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Mr,Gnanapandithan,

 

There could be many factors related to your problem. From the face value very high travel speed looks to be the culprit. A reduction of travel speed followed by a change of gas cylinder/manifold may help. Sometimes gases could be contaminated with moisture.

 

Please see the attached links and the attachments, which would definitely help you for RCA.

 

Thanks.

 

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With+Gas+shielded+Flux+Cored+Wires.pdf

prem_nautiyal26

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Aug 8, 2016, 10:23:10 PM8/8/16
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Few years back even I used to get the similar wormholes in my FCAW  Welds (can't disclose the brand).

I tried many variables.

Eventually the only variable that helped was change of brand !!

Also your travel speed of 800mm/min is very high.
Aim for @ 300 to 350 mm/min

Regards

Prem Nautiyal 
9769316004


Sent from my Samsung Galaxy smartphone.

Kannayeram Gnanapandithan

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Aug 9, 2016, 12:21:16 AM8/9/16
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txs, to some extend, what u said is correct. now travel speed reduced to 600 and there was a problem in shielding also. now it is better than earlier

Thanks to goswami also

THANKS & BEST REGARDS,
KG.PANDITHAN, IWE,  AWS-CWI, CSWIP 3.1,
CONSULTANT-WELDING & QUALITY
Mobile no: +919940739349

On Mon, Aug 8, 2016 at 8:45 PM, 'prem_nautiyal26' via Materials & Welding <material...@googlegroups.com> wrote:

Few years back even I used to get the similar wormholes in my FCAW  Welds (can't disclose the brand).

I tried many variables.

Eventually the only variable that helped was change of brand !!

Also your travel speed of 800mm/min is very high.
Aim for @ 300 to 350 mm/min

Regards

Prem Nautiyal 
9769316004


Sent from my Samsung Galaxy smartphone.

-------- Original message --------
From: Kannayeram Gnanapandithan <kgpan...@gmail.com>
Date: 06/08/2016 19:13 (GMT+05:30)
To: materials-welding <materials-welding@googlegroups.com>
Subject: [MW:25208] Worm track/hole

Process FCAW, Wire E81T1-B2/Dia 1.2mm, shielding 85%Ar+15%Co2. Flow rate 20lpm. Current 240amps, 26 volt, travel speed 800mm/ minute.    while welding, we are getting defect of wormholes/wormstracks , some time continuous and intermittent on top of the weld. Experts, what would be the reason for this defect?

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Pieper QSI

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Aug 9, 2016, 8:08:51 AM8/9/16
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There can be several causes.

 

Is your material clean? Is your filler metal free of oxidation? Did you check the gas flow at the nozzle? Which cup size are you using? Small size with a gas flow of 20 l/min can result in an unstable arc for example when using 18 mm cup a flow rate of 14-18 l/min should be enough under normal circumstances. What are the welding circumstances, are you sure you don’t have problems with draught in your workshop? Did you check your gas hoses, because small leakage in the hose (or anywhere else in the system) can cause a kind of under pressure in your system by which air can be sucked into the hose.

A slightly lower travelling speed will increase heat input and weld pool will stay longer liquid, so gas will have more time to leave the weld metal.

So several things to try / check!

 

Met vriendelijke groeten / Best Regards,

 

Herman Pieper

QA-QC Inspector / CSWIP + IWI-C Welding Inspector / IWT / Materials Expert

 

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Pieper QSI

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Aug 9, 2016, 8:17:45 AM8/9/16
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Other interesting thing to check is the storage of your filler metals. Especially in case of Flux Cored Wires, if those are folded type instead of seamless bad storage conditions can caused moisture pickup in the flux which definitely will result in wormholes in your weld metal.

 

Met vriendelijke groeten / Best Regards,

 

Herman Pieper

QA-QC Inspector / CSWIP + IWI-C Welding Inspector / IWT / Materials Expert

 

Logo_nieuw_vectorized 60%

Job van der Havestraat 6

8384 DB, Wilhelminaoord

Cell: +31 6 51691215

 

 

Van: 'prem_nautiyal26' via Materials & Welding [mailto:material...@googlegroups.com]
Verzonden: maandag 8 augustus 2016 17:15
Aan: material...@googlegroups.com
Onderwerp: Re: [MW:25231] Worm track/hole

 

 

Few years back even I used to get the similar wormholes in my FCAW  Welds (can't disclose the brand).

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