deep penitrent electrodes
nani...@gmail.com
All 90% of pipelines in SMAW E6010 is using for root & others for other passes depends upon strength criteria!!!!!
E6010 electrode is used for root because these are said to be known as "DEEP PENITRANT ELECTRODS" & specially designed for root.
Now my question was why these E6010 electrods are said to be known as "DEEP PENITRANT ELECTRODS"??? Why these electrods are specially desinged for root? what type of speciallity's are containing these electrods when compared to the other potassium, celleous electrodes? Is any differentation absorbed in their chemical composition?
Dear experts i kindly request u people to help me to know the answers for my questions!!!!!!!!!!!!
With Thanks,
Ratnakar Grandhi
John Henning
I am old enough to remember when Lincoln ElectricÒ had propriety labels for their electrodes such as fast freeze, fill-freeze, fast fill etc. These aptly described their solidification characteristics and welders knew instantly what to expect. EXX10 electrodes are what Lincoln called fast freeze – with a primarily cellulose covering, shielding is provided by CO2 generation and a very thin slag. Because of the thin slag the weld puddle solidifies much more quickly than other electrode types (except EXX11 which have similar solidification characteristics). When welding open root, this rapid solidification makes possible bridging of gaps and carrying a keyhole when used with a whipping motion. The depth of penetration is not an issue, but actually is beneficial in assuring complete penetration and allowing for minor deviations in land thickness. Over the years electrode manufacturers have tailored the flux (covering) composition to enhance the performance with respect to open root welding of pipe by small additions of iron powder and arc stabilizers.
The downside to these electrodes is the production of copious amounts of diffusible hydrogen and problems with cold cracking. In addition, the rapid solidification can result in significantly harder HAZ’s and weld metal. The weld bead is also less visually appealing, usually being coarse and rough.
Hope this helps let me know if you are still unclear.
John
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JASPAL SINGH
contents providing deep penetration and hence are termed as Deep
penetration electrodes.
The coating of these electrodes contains organic materials that turn
into gases in the arc. About 30% of the coating weight is cellulose.
In some countries, paper pulp and wood powder are added to the coating
in certain ratios to reduce the amount of pure cellulose. These
organic compounds in the coating decompose in the arc to from carbon
monoxide, carbon dioxide and hydrogen, which increase the arc tension
and thus, the welding arc becomes stronger and harder. Compared with
other types of electrodes, with the same current values, a 70% deeper
penetration is obtained with cellulosic electrodes.
Regards
JASPAL SINGH CWI-AWS, CSWIP-3.1
Quality Assurance-ISGEC-PED,
Yamunanagar, Haryana (India) PH: +911732307251;
Mob. +918930111441(CUG), +919996624244
On Apr 7, 1:35 am, "John Henning" <jhenn...@deltak.com> wrote:
> I am old enough to remember when Lincoln ElectricÒ had propriety labels for their electrodes such as fast freeze, fill-freeze, fast fill etc. These aptly described their solidification characteristics and welders knew instantly what to expect. EXX10 electrodes are what Lincoln called fast freeze - with a primarily cellulose covering, shielding is provided by CO2 generation and a very thin slag. Because of the thin slag the weld puddle solidifies much more quickly than other electrode types (except EXX11 which have similar solidification characteristics). When welding open root, this rapid solidification makes possible bridging of gaps and carrying a keyhole when used with a whipping motion. The depth of penetration is not an issue, but actually is beneficial in assuring complete penetration and allowing for minor deviations in land thickness. Over the years electrode manufacturers have tailored the flux (covering) composition to enhance the performance with respect to open root welding of pipe by small additions of iron powder and arc stabilizers.
> The downside to these electrodes is the production of copious amounts of diffusible hydrogen and problems with cold cracking. In addition, the rapid solidification can result in significantly harder HAZ's and weld metal. The weld bead is also less visually appealing, usually being coarse and rough.
>
> Hope this helps let me know if you are still unclear.
>
> John
>
> Sent: Wednesday, April 06, 2011 9:46 AM
> To: material...@googlegroups.com
> Subject: [MW:10607] deep penitrent electrodes
>
> Dear Experts,
>
> All 90% of pipelines in SMAW E6010 is using for root & others for other passes depends upon strength criteria!!!!!
> E6010 electrode is used for root because these are said to be known as "DEEP PENITRANT ELECTRODS" & specially designed for root.
>
> Now my question was why these E6010 electrods are said to be known as "DEEP PENITRANT ELECTRODS"??? Why these electrods are specially desinged for root? what type of speciallity's are containing these electrods when compared to the other potassium, celleous electrodes? Is any differentation absorbed in their chemical composition?
>
> Dear experts i kindly request u people to help me to know the answers for my questions!!!!!!!!!!!!
>
> With Thanks,
> Ratnakar Grandhi
>
> --
> To post to this group, send email to material...@googlegroups.com
> To unsubscribe from this group, send email to materials-weld...@googlegroups.com
nani grandhi
i am very much happy to get reply for my question,
sir i got reply for my question but the answers i am getting are out of point......
it means that
i am getting the answers for - what are EXX10 electrodes??? and why they are calling cellulose electrodes??????
but my question was this why E6010 electrodes are called as deep penetration electrodes & why they are using for welding of root only?????
Now i will give an example to get clarity for my question!!!
(i.e) for welding of Gr.x70 pipe in pipeline laying
As per WPS we follow Electrodes are
E6010 is used for root & E 8010G (or) E8010P1 is used for other passes respectively...
here smys of Gr.x70 pipe is 70,000psi (appx)
& UTS of E6010 electrode is 60,000 psi & E8010G (or) E8010P1 electrode is 80,000 psi
we use E8010G (or) E8010P1 electrode to weld Gr.x70 pipe in pipeline which is acceptable because strength of electrode is greater than that strength of pipe.
now
coming for the same analysis for E6010 electrodes
then the above rule is violated & which is not acceptable in the case of welding.
but we prefer to weld (root) with E6010 electrodes, Because these are said to be known as "DEEP PENITRANT ELECTRODES" & specially designed for root only.
NOTE: Here this case fallows for all Grades like Gr.x70,65,60,52,B etc......
now here i am interested to know that " E6010 electrodes are said to be known as "DEEP PENITRANT ELECTRODES"??? Why these electrodes are specially designed for root? what type of speciallity's are containing these electrodes when compared to the other potassium, cellulose electrodes? Is any differentiation absorbed in their chemical composition " ?
Now i hope that i have given clarity in my question, if any doubts in my question plz give me mail so that i will try to explain my question more briefly???
Dear experts i kindly request u people to help me to know the answers for my question!!!!!! i will be waiting for Ur's valuable answers for my question?
With Thanks,
Ratnakar Grandhi,
Gammon India Limited,
Harayana,
09996786895
Cellulosic electrodes have coatings or cores with high cellulosei
For more options, visit this group's bolg at http://materials-welding.blogspot.com/
Fitria Rahman
Deep penetration means that molten metal have the ability to fill out quickly into the side of root wall and slightly below the root. a clear reason is groove design for pipe welding requires molten metal that having the ability to fill out the gap which is only 2mm and then forms its internal reinforcement. we are fully aware that the molten metal in root shall have those characteristics to avoid one of the weld defect that commonly occurs in root side i.e. lack of penetration and incomplete penetration. Cellulose produces a large amount of hydrogen which can raises arc voltage and allows the E6010 to have of such characteristics. penetration.
rgds
Dindo
muthu barathi
All welding electrodes under the category EXX10 are Deep penetration
welding electrodes. Not only E6010 is deep penetration. According to
your base metal strength you have to select the electrodes. After
completion of root pass you have to select next grade as per WPS to be
used. Normally Root has to be softer than hot and fill ups.
I think you are getting confused and better read codes and welding
electrodes manufacturer's recommendation more to get a correct
judgement.
On Sat, 09 Apr 2011 06:41:46 +0530 wrote
>
Deep penetration means that molten metal have the
ability to fill out quickly into the side of root wall and slightly
below the
root. a clear reason is groove design for pipe welding requires molten
metal
that having the ability to fill out the gap which is only 2mm and then
forms
its internal reinforcement. we are fully aware that the molten metal in
root
shall have those characteristics to avoid one of the weld defect that
commonly
occurs in root side i.e. lack of penetration and incomplete
penetration. Cellulose
produces a large amount of hydrogen which can raises arc voltage and
allows the
E6010 to have of such characteristics. penetration.
rgds
2011/4/7 nani grandhi
wel...@googlegroups.com] On Behalf Of nani04...@gmail.com
> Sent: Wednesday, April 06, 2011 9:46 AM
> To: material...@googlegroups.com
> Subject: [MW:10607] deep penitrent electrodes
>
> Dear Experts,
>
> All 90% of pipelines in SMAW E6010 is using for root & others for
other passes depends upon strength criteria!!!!!
> E6010 electrode is used for root because these are said to be known
as "DEEP PENITRANT ELECTRODS" & specially designed for root.
>
> Now my question was why these E6010 electrods are said to be known as
"DEEP PENITRANT ELECTRODS"??? Why these electrods are specially
desinged for root? what type of speciallity's are containing these
electrods when compared to the other potassium, celleous electrodes? Is
any differentation absorbed in their chemical composition?
>
> Dear experts i kindly request u people to help me to know the answers
for my questions!!!!!!!!!!!!
>
> With Thanks,
> Ratnakar Grandhi
>
> --
wel...@googlegroups.com
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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.
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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.
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>
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>
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and meant for educational purposes only, Users must take their own
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>
Thanking You,
Honesty is the best Policy
With Warm Regards,
Muthu Barathi P
Mobile No:00962788269821 (Jordan)
00962775401951
 |
SENTHILKUMAR SWAMINATHAN
S.SENTHILKUMAR
From: muthu barathi <muthu_...@rediffmail.com>
To: material...@googlegroups.com
Sent: Sat, 9 April, 2011 6:28:35 AM
Subject: Re: Re: [MW:10631] Re: 10607] deep penitrent electrodes
KRISHNASAMY MASANAM
The cellulose burns in the arc to form a gas shield of carbon monoxide, carbon dioxide and, in conjunction with the moisture in the coating, produces a large amount of hydrogen, typically 30 to 45ml hydrogen/100gm weld metal. The hydrogen raises arc voltage and gives the electrodes their characteristics of deep penetration and high deposition rates. The high voltage requires a high open circuit voltage of around 70 volts to allow easy arc striking and to maintain arc stability. The forceful arc also results in appreciable amounts of weld spatter and this limits the maximum current that can be used on the larger diameter electrodes. A thin, friable and easily removed slag is produced, giving a rather coarsely rippled weld profile. The slag is also fast freezing so that, unlike most other electrodes, they can be used in the vertical down position - 'stovepiping'.
Electrodes with a sodium silicate binder can be used only on DC electrode positive (reverse polarity). Those with a potassium silicate binder can be used either DC electrode positive or on AC. The electrodes require some moisture in the coating to aid the running characteristics and they must never be baked, as may be done on basic coated electrodes. This has the advantage that the electrodes are tolerant to site conditions. If they become damp, drying at a temperature of around 120°C will be sufficient.
Electrode compositions are only available for welding low carbon non-alloyed steels although nickel additions may be made to improve notch toughness. Charpy-V values of around 27J at -20°C are possible in the unalloyed electrodes. The high hydrogen level means that any steel welded with these electrodes should be selected to have a very high resistance to hydrogen induced, cold cracking (see Connect articles numbers 45 and 46). They should not be used without giving due consideration to the steel composition, restraint and the need for preheat. The characteristics of deep penetration, high deposition rates and the ability to be used vertically down means that the main use for these electrodes is for cross country pipelining although they are used to a more limited extent for welding storage tanks.
This article was written by Gene Mathers.
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Date: Sat, 9 Apr 2011 23:50:55 +0530
From: skuma...@yahoo.co.in
Subject: Re: Re: [MW:10637] Re: 10607] deep penitrent electrodes
To: material...@googlegroups.com
nani grandhi
Due to some personal reasons i am did not check my mail. so, i feel really very sorry for this late.
KRISHNASAMY sir, i gone through the mail & material which u had given & feel really very thankful to u & this groups.
sir, after going through ur material i got a part of clarification for my question and the rest are as follows:
1) "The cellulose burns in the arc to form a gas shield of carbon monoxide, carbon dioxide and, in conjunction with the moisture in the coating, produces a large amount of hydrogen, typically 30 to 45ml hydrogen/100gm weld metal. The hydrogen raises arc voltage and gives the electrodes their characteristics of deep penetration and high deposition rates." it means that all cellulose electrodes are having this type of characteristics so that all cellulose electrodes are said to be known as deep penitent electrodes ?
2) is this effects any changes in the chemical composition of the electrode ?
3) For low hydrogen electrodes / EXX18 are beaked before welding at high temperatures to reduce low hydrogen content in the electrode because to avoid cold cracking or hydrogen cracking. in this case "30 to 45ml hydrogen/100gm weld metal" is reliable? if it is reliable what was the % of hydrogen content in the low hydrogen electrodes?
4) in the above case we r not beaking E6010 electrodes to reduce the hydrogen content in it? is 50 to 100 DEG CENTIGRADE temperature of pre heating for the parent material is enough to to avoid cold cracking? If it possible? plz can u Clarify me sir?
5) here we r not using any post weld heat treatment / post heating process? then only with pre heating of parent material about 50 to 100 DEG CENTIGRADE temperature will prevent hydrogen cracking contains "30 to 45ml hydrogen/100gm weld metal"? is it possible ? how?
i hope my questions are reliable?
So, dear experts i kindly request u people to help me to know the answers for my question!!!!!! i will be waiting for Ur's valuable answers for my question?
With Thanks,
Ratnakar Grandhi.