As a good starting point, arc length should not exceed the diameter of the metal portion (core) of the electrode. For example, an 1/8-inch 6010 electrode is held about 1/8 inch off the base material.
Arc length is critical in determining the arc energy density during TIG welding. For the TIG welding of Mg alloy, the arc length has more impact on the weld penetration and weld surface shape.
The voltage length characteristic of a direct area in an arc welding process is V=(100+40l, where l) is the length of the arc in mm and V is arc voltage in volts. During a welding operation, the arc length varies between 1 and 2mm and the welding current is in the range 200−250A.
For wire (flux-core or MIG) welding, keep a work distance of ⅜ to ½ inch. With stick welding, look to keep that distance ⅛ inch between the rod tip and work piece. “The arc length should not exceed the diameter of the core of the electrode,” Leisner says.
As the arc length increases, the arc gradually grows, so the distance between the end of the electrode and the substrate is larger, and the extended wire is longer.
Welding voltage primarily controls the arc length which is the distance between the molten weld pool and the wire filler metal at the point of melting within the arc. As the voltage is increased, the weld bead will flatten out more and have an increasing width-to-depth ratio.
The welding current and amperage range, arc on time or duty cycle, and incoming power.
To find arc length, start by dividing the arc's central angle in degrees by 360. Then, multiply that number by the radius of the circle. Finally, multiply that number by 2 × pi to find the arc length.
The length of an arc on a circle depends on both the angle of rotation and the radius length of the circle. If you recall from the last lesson, the measure of an angle in radians is defined as the length of the arc cut off by one radius length.
Arc length is a fraction of the circumference of the circle and calculated that way: find the circumference of the circle and multiply by the measure of the arc divided by 360.
CORRECT ARC LENGTH
If the arc is too short, or voltage too low, there is not enough heat to melt the base metal properly and the electrode quite often sticks to the work, giving a high, uneven bead, having irregular ripples with poor fusion.
Some argue that stick welding is stronger than MIG welding, since it offers better penetration for thicker materials. However, MIG welding can provide good welds despite not being as effective on thicker metals, and is better for joining thinner metals with a good finish and less risk of burn-through.
Both types of welding machines produce a high quality of welding finish if you know how to finish up the surface. However, MIG welders are a much better option here because they create nice, clean welds with very little slag on the metal surface.
A 0.024-inch wire would operate at 13 to 15 volts (electrode positive) with a wire feed speed of 130 to 160 ipm, whereas the 0.30-inch solid wire would require 15 to 17 volts and 75 to 100 ipm wire feed speed. These parameters would work well for single-pass flat and horizontal fillet welds.
Welding voltage primarily controls the arc length which is the distance between the molten weld pool and the wire filler metal at the point of melting within the arc. As the voltage is increased, the weld bead will flatten out more and have an increasing width-to-depth ratio.
The voltage and arc length are closely related. The shorter the arc, the lower the arc voltage and the lower the temperature produced, an as the arc lengthens, the resistance increases, thus causing a rise in the arc voltage and temperature.
A welding arc is a high current low voltage electric discharge operating generally in the range of 10 to 2000 amperes and at 10 to 50 volts.
In general, arc faults only occur in systems that are 120 volts or higher, but that is not a hard rule. If the conductors are very close together, even a lower voltage level can create a small arc flash.
As arc length decreases, the arc cone becomes narrower and the arc is more focused (see Figure 7). The result is a weld bead that is more narrow and ropy and the level of weld penetration may decrease very slightly. Conversely, as arc length increases, the arc cone becomes wider and the arc is broader.
The arc length voltage characteristic of a DC arc is given by the equation V = 24 + 4L where V is the arc voltage and 'L' is the arc length in mm. The static volt ampere characteristic of the power source is approximated by a straight line with no load voltage of 80 volts and the short circuit current of 600 amperes.
But to take one example, a high voltage connector operating requirement of 10,000 volts DC, the creep path (arc distance) between two conductors at sea level would be 1/2 inch (12.7mm), and at 70,000 ft.
Voltage too high: Too much voltage is marked by poor arc control, inconsistent penetration and a turbulent weld pool that fails to consistently penetrate the base material.
The arc length depends on the arc stability, the weld current and the concentricity of the part.
Welding with 12V automotive batteries is very common in the off-road world, and rightfully so. This is the least expensive and least complex method to melt two pieces of metal together.