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Why is it so?I was looking for information related to welding polarity on the Internet and found quite a lot of conflicting information. Not just a bit different the complete opposite. I was also distracted by some of the archaic terminology that some authors insist on using. DCSP (DC Straight Polarity) and DCRP (DC Reverse Polarity) for example, should, in my view, be dropped from the welding vocabulary. I realise many of you grew up with that terminology but now, it has no meaning.DCSP used to be the conventional polarity used in SMAW (also called ARC and STICK welding). The electrode is negative, and the work is positive (DCEN) because this gave better penetration. DCRP (DCEP) was used if less penetration was needed when, for example, welding thin sheets. Those days of bare electrodes are long gone and now flux covered electrodes like the 6010 give best penetration using DCRP (DCEP).DCSP and DCRP no longer reflect the original use and do not give any hint to the actual polarity being used. They are misleading, confusing and many dont know what they mean. For example, the AWS defines STRAIGHT POLARITY:Is when the flow of electrons travels from the workpiece, which is the negative pole, to the electrode, the positive pole.https://awo.aws.org/glossary/straight-polarity/Even the AWS cant come to grips with it. Its definition of reverse polarity is also wrong.Then there is polarity and penetration.Universal Technical Institute - Without reference to a specific process:Its important for a welder to know the meaning of polarity and understand how it affects the welding process. Typically, electrode-positive (reversed polarity) welding results in deeper penetration.https://www.uti.edu/blog/welding/welding-polarityThat is not the typical case at all. In TIG welding, where the electrode is not consumed, DCEN is used and about 67% of the arc heat (and consequent penetration) is delivered to the work piece via a stream of electrons. If the polarity is reversed (DCEP), the electrode gets very hot and the work is bombarded by a stream of positive Ions causing cathodic etching (cleaning).In GMAW, where the electrode is consumed, the use of DCEP heats the electrode and the melted electrode is transferred to the weld pool via the metallic arc along with its heat. This heat transfer tends to balance heat distribution and helps ensure that there is sufficient penetration.There are many other variables affecting penetration including joint preparation, the use of flux, flux composition, transfer mode and shielding gas.The statement DCEP gives better penetration is not true unless it is fully qualified with the process, parameters, shielding etc. In a different context, even using the same process, DCEN might give better penetration.Some sort of on-line consensus would be good.Jack
Reply:Just wait until you find out that "electron flow" isn't really a thing, and has nothing to do with current in the conventional sense
Last edited by JDM Welder; 4 Weeks Ago at 11:40 PM.Panasonic YC-300BP2Panasonic YC-200BL3Suzukid Arcway 180Lincoln Idealarc R3R-400Thermal Dynamics Cutmaster 52Everlast Power i-MIG 230iEverlast PowerArc 300STDenyo DLW-400LSW...and other assorted garbage
Reply:
Originally Posted by Jack Ryan
Why is it so?I was looking for information related to welding polarity on the Internet and found quite a lot of conflicting information. Not just a bit different the complete opposite. I was also distracted by some of the archaic terminology that some authors insist on using. DCSP (DC Straight Polarity) and DCRP (DC Reverse Polarity) for example, should, in my view, be dropped from the welding vocabulary. I realise many of you grew up with that terminology but now, it has no meaning.DCSP used to be the conventional polarity used in SMAW (also called ARC and STICK welding). The electrode is negative, and the work is positive (DCEN) because this gave better penetration. DCRP (DCEP) was used if less penetration was needed when, for example, welding thin sheets. Those days of bare electrodes are long gone and now flux covered electrodes like the 6010 give best penetration using DCRP (DCEP).DCSP and DCRP no longer reflect the original use and do not give any hint to the actual polarity being used. They are misleading, confusing and many dont know what they mean. For example, the AWS defines STRAIGHT POLARITY:Is when the flow of electrons travels from the workpiece, which is the negative pole, to the electrode, the positive pole.https://awo.aws.org/glossary/straight-polarity/Even the AWS cant come to grips with it. Its definition of reverse polarity is also wrong.Then there is polarity and penetration.Universal Technical Institute - Without reference to a specific process:Its important for a welder to know the meaning of polarity and understand how it affects the welding process. Typically, electrode-positive (reversed polarity) welding results in deeper penetration.https://www.uti.edu/blog/welding/welding-polarityThat is not the typical case at all. In TIG welding, where the electrode is not consumed, DCEN is used and about 67% of the arc heat (and consequent penetration) is delivered to the work piece via a stream of electrons. If the polarity is reversed (DCEP), the electrode gets very hot and the work is bombarded by a stream of positive Ions causing cathodic etching (cleaning).In GMAW, where the electrode is consumed, the use of DCEP heats the electrode and the melted electrode is transferred to the weld pool via the metallic arc along with its heat. This heat transfer tends to balance heat distribution and helps ensure that there is sufficient penetration.There are many other variables affecting penetration including joint preparation, the use of flux, flux composition, transfer mode and shielding gas.The statement DCEP gives better penetration is not true unless it is fully qualified with the process, parameters, shielding etc. In a different context, even using the same process, DCEN might give better penetration.Some sort of on-line consensus would be good.Jack
Reply:To clarify my view..
Originally Posted by Oldiron2
Those terms have meaning to many people, whether or not you like them or choose to use them yourself. I could even argue that when trying to teach younger, less disciplined or perhaps retarded people, "Straight Polarity" can be explained as meaning the gun, torch or holder goes to the straight (-) side of the power supply, and as such, is more likely to be remembered.
Reply:
Originally Posted by JDM Welder
Just wait until you find out that "electron flow" isn't really a thing, and has nothing to do with current in the conventional sense
Reply:How would manufactures tell users how to connect the leads for specific rods? I have not seen red and black terminals in years. What convention do you suggest for describing connections to a weldor?
Reply:
Originally Posted by Jack Ryan
Anyway, my point is, if someone is going to write a book or WEB article, be precise and get it right.Thanks for your comments.Jack
Reply:
Originally Posted by tapwelder
How would manufactures tell users how to connect the leads for specific rods? I have not seen red and black terminals in years. What convention do you suggest for describing connections to a weldor?
Reply:
Originally Posted by Oldiron2
I took your first post to mean that all the "archaic terminology" shouldn't be used anywhere, including here. I still disagree about it being archaic, even if not as formal as the newer terms (that are more unwieldy for common use).
Reply:I guess the thing to remember is: DCEP usually gives deeper penetration on stick, and DCEN usually gives deeper penetration on TIG. I don't understand why -- I've tried to figure it out, but never came up with an understandable explanation -- so now I just remember it by rote. And dispense with the "straight polarity" and "reverse polarity" terms. As for which direction the electrons and current travel -- I'll leave that to Ben Franklin and the rest of them to thrash it out. I just generally remember / arbitrarily define current and electrons as traveling from negative to positive, or from anode to cathode. "Cathode" has more letters than "anode" so I use that to remember cathode = + and anode = -.
Reply:Terms don't just fall out of the welding vernacular overnight but common usage has changed. I don't tell the apprentice when setting that i need straight or reverse polarity i say i need my lead for the stinger or wire feeder to be positive on negative. I try to explain at the appropriate time that electrode positive is also known as reverse polarity and electrode negative is called straight polarity.
Reply:That's why I like AC!
Reply:
Originally Posted by StandarDyne
I guess the thing to remember is: DCEP usually gives deeper penetration on stick, and DCEN usually gives deeper penetration on TIG. I don't understand why -- I've tried to figure it out, but never came up with an understandable explanation -- so now I just remember it by rote. And dispense with the "straight polarity" and "reverse polarity" terms. As for which direction the electrons and current travel -- I'll leave that to Ben Franklin and the rest of them to thrash it out. I just generally remember / arbitrarily define current and electrons as traveling from negative to positive, or from anode to cathode. "Cathode" has more letters than "anode" so I use that to remember cathode = + and anode = -.
Reply:
Originally Posted by rexcormack
That's why I like AC!
Reply:en and ep, would be simple/easy. i got a cv/cc machine that refers to cc as "variable voltage". it goes on in other trades as well, when u really look at it, the ones that bother me is , the dr. that came up w/ "near sighted and far sighted", along w/ the lawyer who came up w/ "dismissed w/ prejudice and w/o prejudice", as for as i'm concerned, they got those *** backwards. at the rate were going w/ our sick societies - get used to iit, pretty soon mother, father, sister etc. will be replaced w/ "birther people" etc., or man and woman will be replaced. i already saw a diff in "mothers day" this yr.. so itll be like welding, several names to the point some what know what the heck the other is talking aboutLast edited by 123weld; 4 Weeks Ago at 01:57 PM.
Reply:
Originally Posted by MISSING LINK
With Tig it isn't about penetration. You have AC or DCEN.
Reply:Bottom line..................terms change with the times(shrug)
Reply:
Originally Posted by StandarDyne
I guess the thing to remember is: DCEP usually gives deeper penetration on stick, and DCEN usually gives deeper penetration on TIG. I don't understand why -- I've tried to figure it out, but never came up with an understandable explanation -- so now I just remember it by rote. And dispense with the "straight polarity" and "reverse polarity" terms. As for which direction the electrons and current travel -- I'll leave that to Ben Franklin and the rest of them to thrash it out. I just generally remember / arbitrarily define current and electrons as traveling from negative to positive, or from anode to cathode. "Cathode" has more letters than "anode" so I use that to remember cathode = + and anode = -.
Reply:
Originally Posted by Eelspike
Terms don't just fall out of the welding vernacular overnight but common usage has changed. I don't tell the apprentice when setting that i need straight or reverse polarity i say i need my lead for the stinger or wire feeder to be positive on negative. I try to explain at the appropriate time that electrode positive is also known as reverse polarity and electrode negative is called straight polarity.
Reply:
Originally Posted by rexcormack
That's why I like AC!
Reply:
Originally Posted by StandarDyne
Indeed. And AC is half EP and half EN. (Assuming no balance control. ) But even if the AC balance is set to 99.999% EN, it's still going to give less penetration than DCEN. But I said that already. Sometimes, but not always. There are a lot of rods that you can stick weld with using either DCEP, AC, or DCEN. If you want less penetration, you can use AC, or -- for even less -- DCEN. Can you give an example? I've never heard those terms used with anything except welders. I've heard of "polarized" plugs, but those are for AC, not DC.
Reply:
Originally Posted by MISSING LINK
With Tig it isn't about penetration.
Reply:If you didn't know what either meant it is so easy to find out. If your learning isn't that like the very first thing you would be taught or learn.Takes 5 seconds to look up and find the meaning. With all the abbreviations for everything today on the internet this old stuff shouldn't be that hard.One quick search and got the answer. http://www.minaprem.com/joining/weld...n-arc-welding/Depending on the connection of base metals and electrode with the ports of power supply, DC polarity can be subdivided into two categoriesDirect Current Straight Polarity (DCSP) and Direct Current Reverse Polarity (DCRP). It is to be noted that for AC supply, both polarities occur one after another in every cycle for a number of times (equals to frequency of supply).DCSP or DCENBase plate is positive and electrode is negative.DCRP or DCEPBase plate is negative and electrode is positive.Last edited by danielplace; 4 Weeks Ago at 08:29 PM.
Reply:
Originally Posted by danielplace
If you didn't know what either meant it is so easy to find out. If your learning isn't that like the very first thing you would be taught or learn.Takes 5 seconds to look up and find the meaning. With all the abbreviations for everything today on the internet this old stuff shouldn't be that hard.One quick search and got the answer. http://www.minaprem.com/joining/weld...n-arc-welding/Depending on the connection of base metals and electrode with the ports of power supply, DC polarity can be subdivided into two categoriesDirect Current Straight Polarity (DCSP) and Direct Current Reverse Polarity (DCRP). It is to be noted that for AC supply, both polarities occur one after another in every cycle for a number of times (equals to frequency of supply).DCSP or DCENBase plate is positive and electrode is negative.DCRP or DCEPBase plate is negative and electrode is positive.
Reply:
Originally Posted by Jack Ryan
My original point was that not all WEB sites agree. As an obvious example, look up those same acronyms in the AWS glossary - the complete opposite.Jack
Originally Posted by danielplace
They do except when someone screws up the text. There is ONLY ONE meaning that has ever been or ever will be correct for these terminologies.
Reply:
Originally Posted by Jack Ryan
Yes, they got the definition wrong for both straight and reverse. Two errors that appear not to be copy/paste related. And yet it is still there.In many places though, a complete lack of understanding is displayed on WEB sites (text and YouTube) and even in reference books, explanations are ambiguous and sometimes wrong.Given the number of posts asking the same questions and complaining about the same contradictory statements I think we can safely assume there is a general lack of clarity.I too can identify correct statements but I pity someone who doesn't already know trying to find the correct answers.Jack
Reply:
Originally Posted by Jack Ryan
My original point was that not all WEB sites agree. As an obvious example, look up those same acronyms in the AWS glossary - the complete opposite.
Reply:
Originally Posted by danielplace
Jack,I didn't read all the posts made but yea I am sure you can find plenty of crappy welding info out there in all forms. Like that with anything today. The internet age. Can't trust all you read or even see.Once a mistake has been made in a major publication like the AWS that isn't ever fixed is going to spread that false info far and wide as it is quoted and repeated elsewhere time and time again. I believe this is how it snowballs because many of the welding articles are written by people that may not even know welding. Then you tubers know they are right because they just read it 5 minutes before making the video so many ways for someone to get it wrong.
Reply:
Originally Posted by Oldiron2
As I said earlier and Daniel states in more detail, that is clearly an error which I doubt you'll find anywhere in AWS written documents. It doesn't help your general argument at all.
Reply:I was less confused before I started reading this thread. It seems to me that deeper and better penetration are not always the same thing and maybe we are really look for useful - effective - manageable penetration in each of the many welding processes. When someone states that in Dc welding the current is not really flowing from negative to positive that just seems counter to the lived experience of this welded. In DCEC (DCSP) with flux-core welding with say Lincoln NR-233 or Coreshield 8 vertical up the wire will sometimes dig a hole if you lose flux coverage, run to hot or don't aim the wire down a little. To me the penetration profile of that family of flux core wires is a narrow cone deeper than it is wide and as you travel up you point the wire and therefore cone down so the molten metal doesn't spill back out these wires can have an annoying tendency toward lack of fusion at the toes. Conversely with the dual shield wires on DCEP (DCRP) it seems as if there is a wider round bottomed penetration profile that consequently washes in more readily at the toes. I alway thought this was explained by the friction of the electrons either flowing directly into the base metal on SP from the electrode in a narrow focus stream or on RP the electrons flowing back to the electrode from a wide swath of the base metal. I thought all this was confirmed by the way TIG welding acts. I also a long time ago came to believe that RP processes act like the cleaning action we see from the positive balance part of the cycle on AC tig brakes the oxide layer on aluminium it so that welding on RP helps and even forcefully expels contaminants from the weld puddle and generally result in a more homogenous mix of filler and base metal and a cleaner weld in general. This also meant that i believed the on SP we lose the cleaning action although i do see that once fluid the puddle will still homogenize.
Reply:I believe PENETRATION is a word with numerous definitions. Penetration is akin to fusion. 6010 stick is known for good penetration, it is somewhat violent in getting in there, splashing away surface metal, getting down to doing its own cleaning. That isn't to say you can successfully weld over a crack without grinding it open. DEEP penetration is unnecessary in a well prepared joint. Good fusion becomes the important factor.An optimist is usually wrong, and when the unexpected happens is unprepared. A pessimist is usually right, when wrong, is delighted, and well prepared.
Reply:That is really good, lots of confusion between the 2.www.urkafarms.com
Reply:There is an avalanche of plagiarism that copies all the rubbish across the internet. Once it becomes fact, it ends up in books as well.
Reply:Interesting read.Retired Old GuyHobart 210Lincoln AC/DC 225/125 Evolution 14 Saw
Reply:
Originally Posted by Eelspike
I was less confused before I started reading this thread. It seems to me that deeper and better penetration are not always the same thing and maybe we are really look for useful - effective - manageable penetration in each of the many welding processes. When someone states that in Dc welding the current is not really flowing from negative to positive that just seems counter to the lived experience of this welded. In DCEC (DCSP) with flux-core welding with say Lincoln NR-233 or Coreshield 8 vertical up the wire will sometimes dig a hole if you lose flux coverage, run to hot or don't aim the wire down a little. To me the penetration profile of that family of flux core wires is a narrow cone deeper than it is wide and as you travel up you point the wire and therefore cone down so the molten metal doesn't spill back out these wires can have an annoying tendency toward lack of fusion at the toes. Conversely with the dual shield wires on DCEP (DCRP) it seems as if there is a wider round bottomed penetration profile that consequently washes in more readily at the toes. I alway thought this was explained by the friction of the electrons either flowing directly into the base metal on SP from the electrode in a narrow focus stream or on RP the electrons flowing back to the electrode from a wide swath of the base metal. I thought all this was confirmed by the way TIG welding acts. I also a long time ago came to believe that RP processes act like the cleaning action we see from the positive balance part of the cycle on AC tig brakes the oxide layer on aluminium it so that welding on RP helps and even forcefully expels contaminants from the weld puddle and generally result in a more homogenous mix of filler and base metal and a cleaner weld in general. This also meant that i believed the on SP we lose the cleaning action although i do see that once fluid the puddle will still homogenize.
Reply:
Originally Posted by Jack Ryan
Yes, absolutely.There is an avalanche of plagiarism that copies all the rubbish across the internet. Once it becomes fact, it ends up in books as well.Jack
Reply:
Originally Posted by Willie B
I believe PENETRATION is a word with numerous definitions. Penetration is akin to fusion. 6010 stick is known for good penetration, it is somewhat violent in getting in there, splashing away surface metal, getting down to doing its own cleaning. That isn't to say you can successfully weld over a crack without grinding it open. DEEP penetration is unnecessary in a well prepared joint. Good fusion becomes the important factor.
Reply:
Originally Posted by 123weld
its called "disinformation", which is becoming a serious matter. it should be flagged and reported to google. maybe try facebook and twitters, they are fact checked
Reply:
Originally Posted by 123weld
its called "disinformation", which is becoming a serious matter. it should be flagged and reported to google. maybe try facebook and twitters, they are fact checked
Reply:The thread was about references on the WEB and sometimes also in books that are contradictory or just straight out wrong. In particular, discussions about polarity and penetration.
Reply:
Originally Posted by 123weld
its called "disinformation", which is becoming a serious matter. it should be flagged and reported to google. maybe try facebook and twitters, they are fact checked
Reply:I agree Jack! I went to the Lincoln's "Procedure Handbook of Arc Welding" looking for some stainless dual shield info. So i found the old TIG welding penetration profiles that have alway stuck in my head affecting the way I think about puddle shape and puddle management across processes. I realize all processes act differently depending on a lot of variables. This is from the 13th edition of the handbook page 9.4-2. I love Lincoln for there long term support of the welding industry and educational programs.
Reply:The Lincoln's "Procedure Handbook of Arc Welding is very good book for learning the welding trade. I used the book when I was 14 years old to learn welding. Dave
Originally Posted by Eelspike
I agree Jack! I went to the Lincoln's "Procedure Handbook of Arc Welding" looking for some stainless dual shield info. So i found the old TIG welding penetration profiles that have alway stuck in my head affecting the way I think about puddle shape and puddle management across processes. I realize all processes act differently depending on a lot of variables. This is from the 13th edition of the handbook page 9.4-2. I love Lincoln for there long term support of the welding industry and educational programs.
Reply:
Originally Posted by Jack Ryan
That would be a full time job for an army of editors/checkers. I think Facebook is much worse - or is it better? There are a lot of experts there.I doubt Google cares.Jack
Reply:
Originally Posted by StandarDyne
Somebody please SAVE US from all these terrifying WORDS and IDEAS!!!
Reply:
Originally Posted by 123weld
there is no "somebody" that gonna save the people. the people shoulda saved themselves. that is why we r where we r today - "in peril"
Reply:
Originally Posted by Jack Ryan
Why is it so?I was looking for information related to welding polarity on the Internet and found quite a lot of conflicting information. Not just a bit different – the complete opposite. I was also distracted by some of the archaic terminology that some authors insist on using. DCSP (DC Straight Polarity) and DCRP (DC Reverse Polarity) for example, should, in my view, be dropped from the welding vocabulary. I realise many of you grew up with that terminology but now, it has no meaning.DCSP used to be the conventional polarity used in SMAW (also called ARC and STICK welding). The electrode is negative, and the work is positive (DCEN) because this gave better penetration. DCRP (DCEP) was used if less penetration was needed when, for example, welding thin sheets. Those days of bare electrodes are long gone and now flux covered electrodes like the 6010 give best penetration using DCRP (DCEP).DCSP and DCRP no longer reflect the original use and do not give any hint to the actual polarity being used. They are misleading, confusing and many don’t know what they mean. For example, the AWS defines STRAIGHT POLARITY:Is when the flow of electrons travels from the workpiece, which is the negative pole, to the electrode, the positive pole.https://awo.aws.org/glossary/straight-polarity/Even the AWS can’t come to grips with it. Its definition of reverse polarity is also wrong.Then there is polarity and penetration.Universal Technical Institute - Without reference to a specific process:It’s important for a welder to know the meaning of polarity and understand how it affects the welding process. Typically, electrode-positive (reversed polarity) welding results in deeper penetration.https://www.uti.edu/blog/welding/welding-polarityThat is not the typical case at all. In TIG welding, where the electrode is not consumed, DCEN is used and about 67% of the arc heat (and consequent penetration) is delivered to the work piece via a stream of electrons. If the polarity is reversed (DCEP), the electrode gets very hot and the work is bombarded by a stream of positive Ions causing cathodic etching (cleaning).In GMAW, where the electrode is consumed, the use of DCEP heats the electrode and the melted electrode is transferred to the weld pool via the metallic arc along with its heat. This heat transfer tends to balance heat distribution and helps ensure that there is sufficient penetration.There are many other variables affecting penetration including joint preparation, the use of flux, flux composition, transfer mode and shielding gas.The statement “DCEP gives better penetration” is not true unless it is fully qualified with the process, parameters, shielding etc. In a different context, even using the same process, DCEN might give better penetration.Some sort of on-line consensus would be good.Jack
Reply:
Originally Posted by Oldiron2
You missed his point entirely, IMHO. His comment ("Somebody please SAVE US from all these terrifying WORDS and IDEAS!!!") was about the political correct-speak, the crazy ideas about grade-school kids being told to decide their gender, and such and conservative ideas being deleted/banned. You are indirectly right in the sense that there's a real purpose in such nonsense though---it's to destroy our system of civilization and replace it with a Marxist society with them at the top, controlling everything.Yes, the nation's biggest problems are because a relatively small number of people have risen to positions of power, both in and out of government, and are controlling the media, corrupting the top law enforcement agencies, and feeding the general public many lies. The tops of both parties include some, although the majority of the worst offenders constitute the demoncrap party. Have you seen the movie 2000 Mules? It contains incontrovertible data such as even local Police and DA's rely upon to convict lots of criminals.
Reply:
Originally Posted by MinnesotaDave
DCEN, DC-, DC straight: All mean the stinger or tig torch are negative. They also mean the electricity is "flowing" from the stinger to the workpiece.DCEP, DC+, DC reverse: Stinger or tig torch are positive.In tig welding it is easy to see which "direction" current "flows" by how the tungsten reacts.In DC+ the electricity flows into the tungsten - causing it to ball up and burn back.As a result, greater depth of fusion (penetration) is in DC- and the tungsten can handle the current.In stick, although the "flow" is the same, the result on depth of fusion is reversed."...there is a jet action and/or expansion of gases in the arc at the electrode tip. This expansion causes the molten metal to be propelled with great speed across the arc. The molten metal impacts the base metal with greater force. This heavy impact on the base metal helps to produce deep, penetrating welds." ~Modern Welding 1997 Althouse, Turnquist, Bowditch, and Bowditch."As far as I know, this is the current
theory on how this all works and what it all means.None of my textbooks have it any other way.As far as "on-line consensus" goes - a consensus is not of much value. |
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发表于 2022-6-20 15:51:30