Basic Welding Circuit, Arc Shielding, and Nature of the Arc

By RobotWorx

To understand an arc welding system, several properties of welding need to be understood. The basic welding circuit, arc shielding, and the nature of the arc are three of the most basic concepts of arc welding.

A basic arc welding circuit contains several components: a shielding gas supply, a power source, an electrode supply, and a welding gun. The shielding gas supply, as it sounds, distributes shielding gas through a hose to the welding gun to aid in the welding process. The gas is usually stored is a cylinder near the welding robot arm. The power source provides the electricity through one of several types of designs including transformer and inverter. The electricity is vital is creating and maintaining a welding arc that melts and joins metal parts together. The electrode supply stores and feeds the metal electrode to the welding torch. This electrode is what carries the electricity to the part being welded. In some types of arc welding, the electrode is consumable and melts into the part. The welding gun in an industrial robot application is mounted to the wrist of the robot arm. The welding gun represents one end of the welding circuit and is where the welding actually happens. The electrode exits the tip, or nozzle, of the welding gun and makes contact with the metal part to initiate the arc, then keeps close proximity to maintain the arc.

Arc shielding is an important part of the arc welding process. Once the arc is established, it needs to remain in an inert environment around the weld pool. This inert environment is essential in ensuring that rust, holes, and other imperfections are avoided and weld quality is high. Because oxygen is generally what causes rust and poor weld quality, argon, carbon dioxide, and helium are common shielding gases.

The nature of the arc in arc welding refers to process of the electricity from the power supply flowing through the welding gun and between two electrodes. Different types of current, electrodes, shielding gases, and metal being welded are used depending on the desired outcome, type of part being welded, current, and polarity.

RobotWorx stocks and sells fully reconditioned industrial welding robots from FANUC Robotics and Motoman Robotics. The FANUC ArcMate 120iB industrial robot arm and the Motoman EA1900N robot arm are both popular welding robot arms that weld with precision and flexibility. To inquire about these and other industrial welding robots, contact the experts at RobotWorx by calling 740-251-4327 or visit our contact page.