Hello Samir,
From my experience I would like to state the change of coating type is not the single contributing factor. Basic coating(15) generates slightly thicker slag, which sometimes leads to a little more chipping and "Cribbing" on the part of the welders.In the end weld may not be shiny , but would be sound and defect free. On the contrary rutile coated electrodes (16) would generate shiny weld beads much to the liking of the welders but the may have a compromise in the mechanical properties of the weld.
Semi basic(17) coating is a balance of the two coating types mentioned above.
Often S.S electrodes may not function as desired due to:-
- improper current setting (higher current) causing electrodes to become red hot and resultant damage to the coating.
- based on the manufacturer's recommendations a change from 15 to 16 may require some current adjustment
- if the arc is concentric or eccentric.If the coating is non uniform, this may happen which will significantly affect the burning characteristics.From smooth type the arc may become noisy generating with a lot of spatters.
- If the electrode core wire is "Stainless" or Non Stainless .If it the second case the the formulations of the coating will decide the "ultimate " weld chemistry and any compositional malfunctioning in the coating could cause poor operating behaviors of electrodes. Generally for S.S welding electrodes manufacturers are always more assured of the quality if the core wire is " Stainless ".
- Often a "bad electrode batch" could spoil the whole show.
- Heating in the holding oven. By default hermetically sealed S.S welding electrodes may be taken out of the "electrode cans" and be put straight on the job. However to avoid moisture pickup the electrodes should be stored in the "portable ovens" @ typically 100-125 Deg C or as recommended by the manufacturer.
The advice would be go back to the manufacturer, call their field representative and arrange for a field quality test.If they're also not happy with the performance ask for a change of the whole batch.
In addition look though the BOC guidelines on various practical tips on fundamentals of SAW and hope to hear from you on the ultimate outcome.
Thanks.
Pradip Goswami,P.Eng.IWE
Welding & Metallurgical Specialist
From: materials-welding@googlegroups.com [mailto:materials-welding@googlegroups.com] On Behalf Of Samir Mehta
Sent: Sunday, December 23, 2012 5:47 AM
To: materials-welding@googlegroups.com
Subject: Re: [MW:16318] AWS E347-15 E347-16 Stainless Steel Welding Rod
Thks for the advice, also u r requested to go through the attachment and do the needful pls
On Sat, Dec 22, 2012 at 9:09 PM, c sridhar <sridhar305@yahoo.com> wrote:
difference between E347-15 and E347-16. as initially we were using E347-15 and it working good but now we hv changed toE347-16E 347-15 is a basic version of 19/10/Nb and welded using DC EP (+) Polarity, while E347-16 is a rutile version of same 19/10/Nband welded using AC (or) DC EP.In fact it should be easier to weld with rutile type ( E347-16) and it gives good finish compared to basic type. Current for both aresame and pl. check.Sridhar.
From: Nandesh Kumar <nandeshkumar@rocketmail.com>
To: materials-welding@googlegroups.com
Sent: Saturday, 22 December 2012 2:45 PM
Subject: Re: [MW:16304] AWS E347-15 E347-16 Stainless Steel Welding Rod
--
What is your application of the said electrodes?
What complaint that the welders are complaining? What do you mean by "Quality of the electrodes"?
Also, what is the brand and trade name of both. Or else contact manufacturer, who is the best advisor.
ವಂದನೆಗಳೊಂದಿಗೆ / Best regards,
Nandesh Kumar A
Abu Dhabi, UAEP.S. : Please don't print this e-mail unless you really need to.
--- On Sat, 22/12/12, welding <samirmehta.jnd@gmail.com> wrote:
From: welding <samirmehta.jnd@gmail.com>
Subject: [MW:16297] AWS E347-15 E347-16 Stainless Steel Welding Rod
To: materials-welding@googlegroups.com
Date: Saturday, 22 December, 2012, 6:54 AM
Dear Expert,Wt reference to the subjected matter, kindly provide the difference between E347-15 and E347-16. as initially we were using E347-15 and it working good but now we hv changed to E347-16 and our welders are starts complaining ab the quality of electrode. pls advice if it need some other Technic to weld or parameter variation.--
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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.
--
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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.
Samir Mehta
Engineer - Welding & Projects
JPIOS
Abu Dhabi - UAE
+971 55 94 25 327
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