Assessing Gouging Electrode Diametere

By PhilThomas (**)

Date 04-10-2006 14:35

Take a look here:

http://www.thermadyne.com/uplFiles/prodSpotlight/89_250_008.pdf

Hope it helps,

By comcam6 (*)

Date 04-11-2006 05:53

Thank you for information ,

then as it shows there is no corelation between electrode diametere and base metal thickness ,
and the main agent of determination of air carbon gouging variable of base metal is its chemical composition.
ok?

By MBlaha

Date 04-11-2006 10:52

Alot depends on what you are doing.

If you are doing demolition, then you want at least 1/4" or bigger.
If you are backgouging a butt joint, it would depend on how much penetration you obtained on your root pass. The deeper you would have to go, the larger diameter. The largest I ever used was 1/2" but that was on a automatic gouger, and we were backgouging 1" diameter steel on a kiln on rollers but only gouging about 1/4"-3/16" deep. There really is not a rule of thumb, just what you can handle and what you are trying to accomplish.

Hope this helps

Mike

By comcam6 (*)

Date 04-11-2006 11:16

Thank you for information ,

in some cases while gouging low-thickness (12mm) plates, I saw a change in color near to the gouging area in EN355N and was concerned about a possible metalurgical change of HAZ area. I have tried to measure the temperature by templestick a few times, but it was negligible.

By GRoberts (***)

Date 04-11-2006 19:12

Any steel that has had carbon arc gouging done on it will have a HAZ regardless of the size of the electrode used. Using good technique will have more to do with the size/extent of the HAZ than the size of the electrode. You would not have any operating problems using up to even 5/8" diameter electrodes on your 1/2" plate. I doubt that you want a gouge that wide though. I am not sure what EN355N plate is, but if it is a 355MPa normalized carbon steel (just a guess on my part based on the nomenclature), proper carbon-arc gouging will not have a detrimental affect on the material. Just make sure you remove all the carbon residue before welding if done. If it is a more hardenable steel, then preheating should be used since the HAZ for proper carbon-arcing cools off faster than the HAZ for welding, it has a propensity to harden more than welding. However, if subsequent welding is done, it eliminates the HAZ from arcing.

By lewis edwards (*)

Date 04-15-2006 02:55

I always select the diamiter of rod that matches the size of gouge that I want . Material or thickness has no affect on the opperation of carbons . It's the amperage that determins the rate of burn consumtion . DCEP works best unless you get a build up of carbon or a piece of carbon breaks of in the joint . When this happens you need to switch to DCEN .