What is CC and CV in welding?
What is CC and CV in welding?
At work we have several different types of welding machines. From a design and arc control standpoint, there are two fundamentally different types of welding power sources. These include power sources that produce a constant current (CC) output and power sources that produce a constant voltage (CV) output.
What kind of arc does a constant voltage power source produce?
Constant voltage power sources have a flat volt-ampere curve.
What is the characteristics of the power supply in arc welding?
The constant voltage power source characteristic is illustrated in Fig. 3. This shows that as the arc length and hence the voltage changes there is a large change in the welding current as the arc lengthens the welding current falls, as the arc shortens the current increases.
What is self regulating arc?
Self-regulation takes place by the mechanism in which after deflection of the arc length in the direction of, for example, increasing the arc length, the system lowers the electrode melting rate – by reducing the arc current.
What is ideal arc length?
Length of arc: The correct arc length varies with each electrode and application. 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.
Is GTAW constant current?
A GTAW power source is a constant-current machine. Unlike constant-voltage power sources, it will do its best to maintain a constant current (i.e., heat) despite changes in the voltage (i.e., arc length). A constant-voltage power source does just the opposite, which is required for gas metal arc welding (GMAW).
What’s the difference between constant current and constant voltage?
The term “constant” is relative. A CC power source will maintain current at a relatively constant level, regardless of fairly large changes in voltage, while a CV power source will maintain voltage at a relatively constant level, regardless of fairly large changes in current.
What power source is used for GTAW?
Welding power sources for gas tungsten arc welding (GTAW) can be alternating current (ac), direct current (dc), or both alternating and direct current (ac/dc) in one machine. The most popular arc welding power source is the transformer-rectifier type.
Why is power source essential for welding?
The primary functions of the power source are to produce sufficient heat to melt the joint and to generate a stable arc and metal transfer. As the welding processes require high current (50-300A) at relatively low voltage (10-50V),the high voltage mains supply (230 or 400V) must be reduced by a transformer.
What three factors are considered when selecting a welding power source?
To evaluate the welding process most appropriate for the job at hand, the following factors would typically be considered:Type of material being welded (see table below)Thickness of the material.The welding position.Type of welding power source and the amount of current available.Time requirements.Working conditions.
Why is GTAW used for root pass?
In addition, GTAW is often used to make root or first-pass welds for piping of various sizes. Because the weld metal is not transferred directly across the electric arc like most open arc welding processes, a vast assortment of welding filler metal is available to the welding engineer.
What are two advantages of GTAW?
Advantages include:Versatility. It can be used to weld almost all metals.Quality. It allows for a high degree of control and when done correctly yields excellent results.Cleanness. GTAW does not create any spatter that must later be cleaned up.Options.
Is MIG GMAW?
Metal Inert Gas (MIG) and Metal Active Gas (MAG) welding are gas metal arc welding (GMAW) processes that use heat created from a DC electric arc between a consumable metal electrode and a workpiece which melt together to create a weld pool that fuses to form a join.
What does GMAW mean in welding?
Gas Metal Arc Welding
Is GMAW a stick welder?
Shielding Method Both SMAW and GMAW rely on a consumable material known as the electrode to create the weld. In recognition of the flux-covered electrode used in SMAW, welders also refer to it as stick welding. GMAW works by a very different technique. Here no layer of flux exists.
Why GMAW can be used in automated welding?
As much of the process is automated, GMAW relieves the weldor (operator) of the burden of maintaining a precise arc length, as well as feeding filler metal into the weld puddle, coordinated operations that are required in other manual welding processes, such as shielded metal arc.
What is CC and CV in welding? At work we have several different types of welding machines. From a design and arc control standpoint, there are two fundamentally different types of welding power sources. These include power sources that produce a constant current (CC) output and power sources that produce a constant voltage (CV) output.…