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Up Topic Welding Industry / Technical Discussions / 6010 Root w/ DCSP???
- - By 1weldnfool Date 05-23-2011 03:04
Im curious to know if anybody out there is using DCSP w/ E6010 on root passes.  Ive been welding for many years and this is a new one on me.  Ive only ever experienced DCRP either in the field or taught in schools.  I just started teachin in Saudi Arabia at a tech school and their using SP and im curious what the effects are w/ this polarity or if anyone has qualified procedures this way.....Thanks
Parent - - By Blaster (***) Date 05-23-2011 03:40 Edited 05-23-2011 03:46
I tried it some years ago after reading Lincoln pipe welding product literature that recommended EN for certain situations... mostly thin wall and/or where internal undercut is a problem. 

Personally I like 6010 open root on EN, alot.   The key hole is easier to manage, particularly on thinner pipe, with a bigger root opening, or up hill.  At our school the guys try it once so they will know what it is like, but their assignments and the procedures used for certification testing are done on EP.  My take is that if a guy can make a good root on EP, if EN is an option it will be easy by comparison.
Parent - - By joe pirie (***) Date 05-23-2011 14:34
6010 is a dc reverse only rod !!!
Parent - By 357max (***) Date 05-23-2011 14:43
The 6010 is recommended to be used on DCEP but a procedure can be qualified with any polarity and current type. IE DCEN for root passes DCEP hot fill & cover. Or if magnetic arc blow is a problem AC with a square wave weld output can be qualified. Another cellulose electrode can be used and that is the 6011 or 1109. Most manufacturers of 6011 have a couple of choices that one may have low slag like the 6010. A good procedure qualification test is worth more than a thousand opinions
Parent - - By qcrobert (***) Date 05-23-2011 16:08
I have only used DCEN with E6010 when welding very thin sheet metal as in guards.  The electrode doesn't have any penetrating power so I don't see how it could be used on open butt pipe.
Parent - By joe pirie (***) Date 05-23-2011 18:36
COPIED FROM FILLER METAL HANDBOOK  6010 DC REVERSE ONLY
If there is an “E” in front of the electrode numbers, it simply means “electrode for arc welding.”

The first two numbers (i.e. 60 in 6010) represent 60,000 pounds of tensile strength per square inch.

The third number (i.e. 1 in 6010) represent position, 6010 is an ALL POSITION rod.

The third and fourth numbers (i.e. 10 in 6010) represent the flux coating.


Stabilizers in the flux is what maintains the arc current.

The last number on the electrode (i.e. 8 in 7018) allows the weldor to know what type of electrical current the electrode utilizes, such as AC, DC+, and/or DC-.  See chart next page.
DIRECTIONS FOR USING THE ELECTRODE CURRENT CHART

 

The following chart will tell the weldor what type of electricity each electrode requires.  The last number of the electrode (i.e. 8 in 7018) is what we are looking at.  The 7018 electrode, for example, means that the electrode is a DC+ electrode. 

 

What this means is that the electrode can weld with the welder leads connected to either the Alternating Current (AC) connection points, or Direct Current (DC) connections point. 

When connecting the electrode leads AC, it doesn’t matter which lead goes to which connection point.  When connecting to the leads to DC it is very important which lead goes to which connector.  The connection points are labeled + (positive) and – (negative). 

 

If the lead which has the electrode holder on it is connected to the + (positive) connection point on the welder, then you will be welding Electrode Positive, which is called Reverse Polarity ( DC+ = Reverse Polarity).  If the electrode holder lead is connected to the – (negative) connection point on the welder, you will be welding Electrode Negative, which is called Straight Polarity ( DC- = Straight Polarity).

 

The “E” on the chart means Either RP (Reverse Polarity) or SP (Straight Polarity).

0 – DC+ only – Reverse Polarity

1 – AC or DC+ (Reverse Polarity – the electrode holder lead connects to the DC + terminal)

2 – AC or DC- (Straight Polarity - the electrode holder lead connects to the DC - terminal)

3 – AC or DC+ or DC- the electrode holder lead can connects to the DC + or – terminal)

4 – AC or DC+ or DC- the electrode holder lead can connects to the DC + or – terminal)

5 - 0 – DC+ only – Reverse Polarity

6 – AC or DC+ (Reverse Polarity – the electrode holder lead connects to the DC + terminal)

7 - AC or DC+ (Reverse Polarity – the electrode holder lead connects to the DC + terminal)



Use this chart for quicker reference:

Electrode Current Chart   (note:  there is not a 7)

0        DC               RP

1        AC/DC         RP

2        AC/DC         SP

3        AC/DC         E (Either RP or SP)

4        AC/DC         E (Either RP or SP)

5        DC               RP

6        AC/DC         RP

8        AC/DC         RP

NOTE
Parent - - By Superflux (****) Date 05-23-2011 18:43 Edited 05-23-2011 18:50
Seems that it would be tough sell to anyone to try to qualify a 6010 on DCEN if it is against the manufacturers specifications.
I'll bet Hartford,or Lloyd's of London would never accept it.
Pipe liner's are famous for swapping the + and - around. That's why they use the same uninsulated clamps for ground and stinger.
And yes, I have used 6010 straight polarity on sheet metal projects around the ranch. I wasn't about to drive 40 miles into town just to buy a handfull of 6011s!
Parent - - By Blaster (***) Date 05-23-2011 19:19
Lincoln clearly includes E6010 DCEN as a viable alternative in their publication "Welidng Pressure Pipe Lines and Piping Systems". 

Here is a link:  http://www.lincolnelectric.com/assets/en_US/Products/Consumable_PipelinerConsumables-Pipeliner-PipelinerLH-D90/c2420.pdf

"Since reverse polarity (DC+) is commonly used by U.S. pipeline
operators for root pass welding, switch to straight polarity (DC-)
when burn through, internal undercut and hollow bead defects
persist. Polarity change is an essential variable in API 1104 code -
requiring a procedure qualification."

There is a picture on page 13 which shows recomended fitup for DCEN.
Parent - By joe pirie (***) Date 05-23-2011 19:42
RIGHT U ARE. lincoln says you can do it and qualify a procdeure.  .l was taught  dc reverse only. every filler metal book i have
says dc  reverse only never seen anyone purposely run it on dc straight but ive seen it accidently and it welds like **** with a whole bunch of splatter
and makes a very distinctive noise.  seems like alot of the textbooks for welding are giving out wrong information
Parent - - By Superflux (****) Date 05-24-2011 04:30 Edited 05-24-2011 04:58
"Polarity change is an essential variable in API 1104 code - requiring a procedure qualification."

I have seen Pipeliners swap leads around, but that is cheating. Using an unqualified/unauthorized change of an essential variable.
Same as if the welder decided since the gap is not right, I'm gonna use MIG!

Do you pipeline QC's let them get away with this?
Still, the original post question remains unanswered, and I too am curious... Has ANYONE in this forum ever used or ever seen a Qualified Procedure utilizing E6010 on DCEN?
Parent - By 357max (***) Date 05-24-2011 15:00
Yes, EN for the root on concrete lined pipe used for salt water gathering lines. Minimum penetration to avoid "burning" the concrete and increasing the unprotected area subject to salt water corrosion.
Parent - By dbigkahunna (****) Date 05-25-2011 01:58
Yes, I have qualified procedures for DCEN for both 5P and 5P+ and also HYP for DH welding.
What you have to watch is your travel speed. You can jam a the pipe up tight and run from top to bottom with one 5/32 on 12 inch pipe. But you are skating and not leaving much bead reinforcement. Contractor can make some footage if you are not watching them.
But when you keep the travel speed between 6-10 IPM on pipe where IUC is a problem running straight can solve the problem. There is some arc stability problems especially on certain later model SA 200 machines. If you have a old short hood and turn it down to 1480rpm you will not believe what the bead will look like.
I have not seen DCEN ran on the newer machines like the Vantage. Machine would probably blink "Are you Sure"
Up Topic Welding Industry / Technical Discussions / 6010 Root w/ DCSP???

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