Re: [MW:14767] Tapered burning of MMA electrode

[Prakash Hegde]

Hi! To share my experience  is i) Excentric Flux coating ii) Improper Flux formulation   Regards   Hegde P.B. --- On Thu, 5/7/12, Materials & Welding <material...@googlegroups.com> wrote: From: Materials & Welding <material...@googlegroups.com> Subject: [MW:14767] Tapered burning of MMA electrode To: material...@googlegroups.com Date: Thursday, 5 July, 2012, 12:14 PM Dear Experts I am Facing a problem in SS 308-16 MMA electrode diameter 2.5 mm  when I start welding It gives tapered burning of electrode what can be the possible reasons from welding point of view and electrode manufacturing point of view??? How this problem can be solved? Regards, Ahmed -- To post to this group, send email to material...@googlegroups.com To unsubscribe from this group, send email to materials-weld...@googlegroups.com For more options, visit this group's bolg at http://materials-welding.blogspot.com/ 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.

[Shadab Ansari]

Dear Ahmed,
There seems to be the manufacturing problem.
Please check the concentricity of the electrodes. Such problem occurs when the coating and the core rod are not concentric.

Warm regards
Shadab ansari

[Nachhattar Singh]

Dear Experts

 

I have an issue where the media to be deployed is FeCL3 solution  so under these

conditions what should be the MOC. The item to be made is valve to be fitted

on the tank and the connecting piping.

 

Please suggest

 

Nachhattar Singh

[Krishnnaa26]

6% Moly Stainless Steels, Duplex and Alloy 20 may serve your purpose.

Krishna

On Jul 5, 7:51 pm, "Nachhattar Singh" <nsi...@librainspection.com>
wrote:

[prem nautiyal]

Hi   The tapered burning of electrode is due to its eccentricity problem which is a manufacturing problem caused during extrusion process of electrode. Please replace the defective electrodes with a new Batch. If you weld with eccentric electrodes you might land up in defects in UT/RT.   Regards   Prem Nautiyal

--- On Thu, 7/5/12, Materials & Welding <material...@googlegroups.com> wrote:

From: Materials & Welding <material...@googlegroups.com> Subject: [MW:14767] Tapered burning of MMA electrode To: material...@googlegroups.com

[Murtaza Ghauri]

Thank you very much for your advice. 
I have tried to compare the welding profile for both types of electrodes i.e center out and center ok electrodes but both electrodes give the same profile. 
Can it be a problem of magnetic arc blow because I felt my electrodes posses some magnetic response? 

---

From: Shadab Ansari <shadaban...@gmail.com>
To: material...@googlegroups.com
Sent: Thursday, July 5, 2012 11:54 AM
Subject: Re: [MW:14768] Tapered burning of MMA electrode

[Ryan Carbonara]

In the old oilfield days for me 15 years ago for SMAW SS overlays the welder would have a scrap piece of plate and would initiate and arc and burn the rod back a 1/4".

 

The rods would often leave porosity on the initiation of the weld bead.

 

They would then start the weld bead with a rod that was evenly burned and warm. This would alleviate their porosity issues on the weld overlay.

 

Ryan 

---

From: material...@googlegroups.com [mailto:material...@googlegroups.com] On Behalf Of Murtaza Ghauri
Sent: Friday, July 06, 2012 4:41 AM
To: material...@googlegroups.com
Subject: Re: [MW:14783] Tapered burning of MMA electrode

[c sridhar]

Mr. Ahmed,

SS or any SMAW electrodes of 2.0 , 2.5, 3.2 mm size electrodes generally have this eccentric coating problem due to light coating given on the core wire.

You can hold the electrode in the electrode holder  burn it and see whether the flux coating burns on one side, i.e., on the thinner side of the coating.

Just reverse the electrode to 180 deg in the holder, burn and and check again whether the flux is over burning on the same side.

If so, then it could be concluded that, the flux coating is eccentric.  This is more practical compared to checking though machine.

sridhar.

---

From: Ryan Carbonara <rcarb...@valv.com>
To: material...@googlegroups.com
Sent: Friday, 6 July 2012 10:22 PM
Subject: RE: [MW:14784] Tapered burning of MMA electrode

[Murtaza Ghauri]

Dear all

Thank you very much for your advice. 
I have tried to compare the welding profile for both types of electrodes i.e center out and center ok electrodes but both electrodes give the same profile. 
Can it be a problem of magnetic arc blow because I felt my electrodes posses some magnetic response? 

---

From: c sridhar <sridh...@yahoo.com>
To: "material...@googlegroups.com" <material...@googlegroups.com>
Sent: Saturday, July 7, 2012 6:02 PM
Subject: Re: [MW:14791] Tapered burning of MMA electrode

[joseph mbé]

Dear expert,

 

could someone please explain this kind of indications on the H beam surfaces (how this happened and also how to correct)? photo here attached.

thank you for your reply.

 

Best regards

 

Joe F  Mbe

QA/QC Engineer

TEL CMR (00237) 33129846

TEL CG (00242) 057388009

mbej...@yhaoo.fr

BP 1155 Pointe Noire

Yesterday is the pass, tomorrow is the future; and today? Today is the present, the gift: Enjoy it!

 

[Umamaheswara Rao]

Dear Joe F Mbe,

 

(Dear experts, please correct me if I am wrong.)

 

 

Normally these type of indications are formed during rolling time (during manufacturing). And these indication are called as scales or some times these may turn into laminations also.

So for further investigation you can cut the specimen as shown in the photo and etch both the surface then you could know whether it is laminations or scales.

If it is a scales then, with your client permission you just flush that area with emery paper wheel only not with grinder. If you do with grinder the it would reduce the thickness. Perform NDT over the area after flushing.

Or else if it is lamination then no doubt the item is rejected.

 

Regards,

P.U.Rao

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--
P.Umamaheswara Rao
Welding Inspector
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00971509045301

[Steven Teo]

Looks brittle.

Dont bother to correct it. Replace it.

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[jaffar ali riyas mohamed nizamin]

Dear Joe, 

           In my suggestion, 1st u will do UT in that specify area, whether if it is a lamination found is rejected , due to some material problem will come sometimes. (or) the lamination is not found means it is easily repairable.....

Thanks..

[joseph mbé]

Hi,

We did UT and there is no lamination defect. the indication can be found only on the surface of the H Beam and is about 2mm deep on the whole surface.

Kindly

 

Joe F Mbe

QA/QC Engineer

TEL CMR (00237) 33129846

TEL CG (00242) 057388009

mbej...@yhaoo.fr

BP 1155 Pointe Noire

Yesterday is the pass, tomorrow is the future; and today? Today is the present, the gift: Enjoy it!

 

---

De : jaffar ali riyas mohamed nizamin <jaffar...@gmail.com>
À : material...@googlegroups.com
Envoyé le : Jeudi 13 juin 2013 6h26
Objet : Re: [MW:17921] Linear indications on H beam

[jaffar ali riyas mohamed nizamin]

Dear Mr.Joe,

       I think it is a ingot problem better to change a material from supplier

[Shoja Larijani]

Dear Mr Joe.

In casting inclusion slags will be picked up in corner of H rolled beam so if sulfur in the material to be more than 005% this problems  will be raised then better to change mat. manufacturer.

Shoja Larijani

Mahab Ghodss Consulating Engineer

[bijoy joseph]

 Dear all,

Do one sample for mechanical and chemical test. if it is meeting the requirement of material standard ,then you can use it.

check one sample after blasting the line mark is visible or not.

joseph

[c sridhar]

 

 

 

 

 Before deciding on the source of the problem,

1.  Change the electrode to 180 ⁰ in the holder and weld . If the tapering occurs  on the       

      same side / area (as in earlier case) while burning,  then it could be a manufacturing

      problem.

 

     If it is on the opposite side, then it could be due to wrong holder / travel angle used  

     during welding. The welder has to change or use proper  holder angle (or)  practice

     to overcome the problems.

 

2.  If the tapering occurs on the same side / area, in spite of 180⁰ rotation in the holder

     it could be due to worn out die used by the manufacturer or drilled hole  in the die not

     meeting the specifications of coating thickness.  It is nothing to do with binders used for  

     bonding the flux  chemicals to the core.
 

     In this case, you can return the entire lot and ask for free replacement.

 

3.  Tapered burning  is a common problem in SS and sometimes  with  MS  (E 6013) 2.40

      mm   size electrodes also. One way to overcome the problem is to use medium coated

      electrode in place of light (flux) coated type. 

 

      E 308-17,  E xxx-17 series SS electrodes with same chemistry  has this extra  thickness  

      of  flux coating  comparatively and also provides straw / golden yellow (or)  light silver

      finish colour weld bead , in place of bluish colour normally associated  with SS  electrode        

      welding which is due to use of excessive current.

 

      These electrodes also does not require any post dressing or grinding.

 

Sridhar.

[Ramin Kondori]

Dear Ahmed:

Maybe you experiencing a simple "Arc Blow" effect...

This happens to be the case in many situations like yours...

We engineers like problems to be complicated but sometimes it is simple...

I'm sure you know about arc blow but take my advise and just take a look at below Lincoln Electric article:

www.lincolnelectric.com

Regards

Ramin Kondori

Sr. QA/QC Engineer

SINOPEC

r.ko...@petroyada.com
+98-2123592322
+98-9132150320

On Thu, Jul 5, 2012 at 11:14 AM, Materials & Welding <material...@googlegroups.com> wrote:

Dear Experts

I am Facing a problem in SS 308-16 MMA electrode diameter 2.5 mm 

when I start welding It gives tapered burning of electrode

what can be the possible reasons from welding point of view and electrode manufacturing point of view???

How this problem can be solved?

Regards,

Ahmed

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[c sridhar]

Yes, it is simple. Arc Blow occurs in Heavy wall thickness and  Alloy steel materials only

Not in austenite SS

---

From: Ramin Kondori <ramink...@gmail.com>
To: material...@googlegroups.com
Sent: Saturday, 6 July 2013 3:28 AM
Subject: Re: [MW:18096] Tapered burning of MMA electrode

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.

[Ramin Kondori]

Sorry for my mistake...

It can't be arc blow as I previously mentioned.

The post is so long that I did not notice that the type of electrode is austenitic stainless steel.

Regards

Ramin Kondori

Sr. QA/QC Engineer

SINOPEC

r.ko...@petroyada.com
+98-2123592322
+98-9132150320

[chandan choudhary]

this is basically due to concentric problem for more detail  you can go through IS 814 code