This disclosure relates generally to welding, and more specifically, to submerged arc welding (SAW). In an embodiment, a welding system includes a gas supply system configured to provide a fluorine-containing gas flow. The system also includes a wire supply system configured to provide welding wire, and a flux supply system configured to provide flux near a welding arc during submerged arc welding (SAW). The system further includes a welding torch assembly configured to receive the fluorine-containing gas flow and the welding wire and to deliver the fluorine-containing gas flow and the welding wire near the welding arc during the SAW.

A welding system includes a welder configured to output welding power to generate an arc between a welding electrode and a workpiece. The welding system also includes a power pin configured to be coupled to the welder in a first orientation or a second orientation. The power pin is configured to switch the welding power from a first polarity to a second polarity when the power pin is switched from being coupled to the welder in the first orientation to being coupled to the welder in the second orientation.

This disclosure relates generally to welding, and more specifically, to submerged arc welding (SAW). In an embodiment, a welding system includes a gas supply system configured to provide a fluorine-containing gas flow. The system also includes a wire supply system configured to provide welding wire, and a flux supply system configured to provide flux near a welding arc during submerged arc welding (SAW). The system further includes a welding torch assembly configured to receive the fluorine-containing gas flow and the welding wire and to deliver the fluorine-containing gas flow and the welding wire near the welding arc during the SAW.

A welding nozzle includes a body having an upper portion and a lower portion. The upper portion is configured to engage with an end portion of a welding gun or torch. The lower portion defines an electrode receiving aperture, and a plurality of gas ports.

An apparatus and method for cleaning an oxide film using a direct current reverse polarity are provided. The apparatus for cleaning an oxide film formed on a workpiece may include a power supply configured to apply direct current power and to include a positive electrode terminal and a negative electrode terminal, the workpiece configured to be electrically connected to the negative electrode terminal to act as a negative electrode to which a current is applied, and a torch having a positive electrode, which is spaced apart from the oxide film by a predetermined distance and is electrically connected to the positive electrode terminal, the torch being installed to be movable relative to the workpiece. The oxide film formed on the workpiece may be removed by applying a reverse polarity direct current between the workpiece, serving as the negative electrode, and the positive electrode to generate an arc.

Disclosed is an arc welding control method of controlling a welding current in short-circuit arc welding of feeding a welding wire toward a base metal and alternating a short-circuit state and an arc state. The arc welding control method includes: executing, in the short-circuit state, a first increase in the welding current with a first slope, a first decrease in the welding current to a first bottom value after executing the first increase, a second increase in the welding current with a second slope after executing the first decrease, and a second decrease in the welding current to a second bottom value that is smaller than the first bottom value after executing the second increase to shift a state to the arc state.

The invention described herein generally pertains to a system and method for generating a negative polarity welding output current waveform to control a welding process. An electric arc welding system generates an electric welding waveform with portions in a negative polarity. A cycle of the electric welding waveform includes a background current phase, a short clearing ramp phase after the background current phase, a peak current phase, and a tail-out current phase of the electric welding waveform, wherein the peak current phase provides a negative peak current level, the tail-out current phase provides a monotonically increasing tail-out current level toward the positive background current level, and the short clearing ramp phase provides a decreasing current level in a positive polarity of current for the electric welding waveform.

A low-back-pressure penetrating arc welding apparatus and a welding method using the same are disclosed. Through vacuuming a central vacuum chamber of a low-back-pressure protection device by a suction device, a plume of a penetrating arc located in the central vacuum chamber, as well as a back side of a keyhole molten pool, are maintained in a negative-pressure vacuum state relative to an argon gas ambience. A pressure gradient in the keyhole molten pool is thus generated that points from a front side of the keyhole molten pool to the back side of the keyhole molten pool. The pressure gradient thus further enhances a stiffness of the front side of the keyhole molten pool as well as a stability of the penetrating arc, resulting in an enhancement in the piercing capability of the penetrating arc, without changing a force distribution and a temperature gradient of the keyhole molten pool.

A welding system includes a welder configured to output welding power to generate an arc between a welding electrode and a workpiece. The welding system also includes a power pin configured to be coupled to the welder in a first orientation or a second orientation. The power pin is configured to switch the welding power from a first polarity to a second polarity when the power pin is switched from being coupled to the welder in the first orientation to being coupled to the welder in the second orientation.

A welding torch system includes a nozzle, a contact tip retainer assembly, and a diffuser assembly. The diffuser assembly couples to the neck of a welding torch. Additionally, the welding torch system includes a contact tip axially secured between the contact tip retainer assembly and the diffuser assembly. Further, the nozzle axially secures the contact tip retainer assembly and the contact tip to the diffuser assembly.