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
Job van der Havestraat 6
8384 DB, Wilhelminaoord
Cell: +31 6 51691215
Van: 'prem_nautiyal26' via Materials & Welding [mailto:materials-welding@googlegroups.com]
Verzonden: maandag 8 augustus 2016 17:15
Aan: materials-welding@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).
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 <kgpandithan@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?
--
http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
To post to this group, send email to materials-welding@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/CAJzm4eNah6%3DE4H6CPk%3DPxyRVVZxdhG72jHEcq1mTXbhf1nkDcg%40mail.gmail.com.
For more options, visit https://groups.google.com/d/optout.
--
http://www.linkedin.com/groups/MaterialsWelding-122787?home=&gid=122787&trk=anet_ug_hm
The views expressed/exchnaged in this group are members personel views and meant for educational purposes only, Users must take their own decisions w.r.t. applicable code/standard/contract documents.
---
You received this message because you are subscribed to the Google Groups "Materials & Welding" group.
To unsubscribe from this group and stop receiving emails from it, send an email to materials-welding+unsubscribe@googlegroups.com.
To post to this group, send email to materials-welding@googlegroups.com.
To view this discussion on the web visit https://groups.google.com/d/msgid/materials-welding/7tkxrbclaqtsqfxe1vnwbb4w.1470669320545%40email.android.com.
For more options, visit https://groups.google.com/d/optout.
No comments:
Post a Comment