GOUGING ELECTRODE USES
Gouging electrodes are made of carbon and have a copper coating.Gouging carbon rods are used for metal removal at fast rates with low power consumption. It is generally used to remove welding defects, excess welds and foundry risers from cast products. Our carbon gouging rods are precisely machined and manufactured in state of the art facilities.
In welding, gouging has been a requirement for many years in several industries and applications, and is one method to scrutinize. Particularly in maintenance and repair, the ability to gouge or groove metal is critical and deserves full consideration. Two of the most common methods of gouging are plasma gouging and air carbon-arc gouging.
Plasma gouging is a variation of plasma cutting, in which the arc is "defocused" slightly by increasing the whole size in the constricting orifice. A cutting arc is directed downward through the metal to blow the molten metal down and out through the kerf, forcing the two pieces of metal to separate. In plasma gouging, the torch is inclined at an angle to the work piece, and the arc plows out a groove on the metal surface and blows the molten metal off to the side. A more intense cutting arc causes a groove too deep and narrow for most applications, so the defocused arc is used for gouging.
The plasma cutting process was invented in 1954 at the Tonawanda Laboratory of the Linde Division of Union Carbide. A young scientist, Robert Gage, discovered that by forcing a gas tungsten arc through a small orifice in a process similar to focusing a beam of light through a lens, the temperature and intensity of the arc could be increased. By passing a fairly high gas flow through this focused arc, it could cut metal.
Plasma gouging was developed as a tool for weld removal and weld preparation. Back gouging was used to remove metal from the reverse side of arc-welded joints to eliminate defects and improve strength. Weld defects such as cracks, porosity, and lack of fusion could be gouged out using a plasma torch and then repaired with a new, sound weld.
Today plasma arc gouging has wider industrial applications, from shipbuilding and maintenance, to heavy equipment manufacturing and repair, to manufacturing of truck bodies, tanks, and steel structures. Plasma gouging removes strong backs, lifting lugs, temporary brackets, tack welds, and rivets. It is also suitable for demolition or salvage operations to disassemble welded structures. In foundries, it removes excess material from castings. Anywhere surplus metal, excess weld, or defects need to be removed, plasma gouging can be used.
AIR CARBON-ARC GOUGING
The process of air carbon-arc gouging is generated between the tip of a carbon electrode and the work piece. The metal becomes molten and a high velocity air streams down the electrode to blow it away and thus leaves a clean groove. It is a simple process to apply, has a high metal removal rate, gouge profile and it can be closely controlled.
However, there are disadvantages: the air jet causes the molten metal to be ejected over quite a large distance and, because of high currents (up to 2000A) and high air pressures (80 to 100 psi), it can be very noisy.
This type of gouging can be applied to a wide range of metals. DC (electrode positive) is normally preferred for steel and stainless steel, but AC is more effective for cast iron, copper and nickel alloys. Typical applications include back gouging, removal of surface and internal defects, removal of excess weld metal and preparation of bevel edges for welding.
This process is the best alternative to traditional gouging more particularly when precision and safety are priorities. With a removal capability of up to 8 kg/h, Plasma gouging improves operating conditions by reducing noise and fumes.
Using the same process as Plasma cutting; it enables the removal of metal efficiently, precisely and cleanly.