Specific AC welding waveforms are utilized to increase the toughness level of austenitic stainless steel above what is achieved using the same welding consumables using standard DC welding waveforms.

A welding or additive manufacturing power supply includes a user interface that receives a user input shielding gas mixture comprising separately adjustable amounts of a first and a second shielding gas. Output circuitry generates a shielding gas customized welding waveform. A memory stores a first plurality of waveform parameters that are associated with the first shielding gas, and a second plurality of waveform parameters that are associated with the second shielding gas. A controller is operatively connected to control operations of the output circuitry, and is configured to determine a third plurality of waveform parameters at least partially defining the shielding gas customized welding waveform. The controller determines the third plurality of waveform parameters from the first and second plurality of waveform parameters and the amounts of the first and second shielding gas.

Embodiments of welding systems and methods for reducing spatter in pulsed welding are disclosed. A welding power source includes a first welding output stud to be electrically connected to a consumable welding electrode and a second welding output stud to be electrically connected to a workpiece. Power electronics generate welding output current pulses. A switching network is connected between the power electronics and the first welding output stud. A controller is connected between the power electronics and the switching network. The controller controls the timing of each welding output current pulse and switches the switching network back and forth between a first welding output current flowing state and a second welding output current impeding state based on the timing. An increase in a decay rate of a trailing edge of each welding output current pulse is effected during the second welding output current impeding state.

A method and apparatus for providing welding type power is disclosed. The output is cyclical, and is a controlled voltage output during the background and/or peak and a controlled current output during the transition up and/or down. During the controlled current portion the output is responsive to output voltage.

An apparatus to provide welding power. The apparatus may include a direct current-alternate current (DC-AC) power converter to output a primary current and a transformer stage. The transformer stage may include at least one power transformer to receive the primary current from the (DC-AC) power converter on a primary side of the transformer stage and to output a first voltage through a first rectifier and a first set of secondary windings disposed on a secondary side of the transformer stage. The transformer stage may further include an auxiliary set of secondary windings disposed on the secondary side to output a second voltage. The apparatus may also include a pair of active unidirectional switches disposed on the secondary side to receive the second voltage from the auxiliary set of secondary windings.

In thin sheet welding, when a heat input amount relative to a sheet thickness is too large, a welding defect such as a deviation from aim due to occurrence of a strain or burn through may easily occur. When a welding current is decreased to reduce the heat input amount, there is an issue in which an arc tends to become unstable. In arc welding that repeats short-circuit and arcing, first heat input period (Th) and second heat input period (Tc) having a heat input amount less than that of first heat input period (Th) are periodically repeated. This reduces the heat input amount into a welding object and suppresses burn through and a strain upon welding while making the arc stable.

Provided is a system for providing pulsed arc starting phase, where the system comprises power conversion circuitry configured to convert input power to welding-type power and output the welding-type power, and control circuitry configured to control the power conversion circuitry to output the welding-type power. The control circuitry is configured to control the power conversion circuitry to output a plurality of welding current pulses during at least a portion of one or both of a run-in period or a ramp period for wire feeding of a welding wire ends, where each of the plurality of welding current pulses is associated with a respective pulse period and a respective pulse duty cycle.

Forward feeding for feeding a welding wire in a direction of a workpiece and backward feeding for feeding in an opposite direction to the forward feeding are alternately performed, and the welding wire is fed at a wire feeding speed cyclically changed in a predetermined cycle and at a predetermined amplitude to perform welding by repeating an arc period and a short-circuit period. Provided during forward feeding, stopping feeding of the welding wire from a time of an elapse of a half cycle of a change of the wire feeding speed to an elapse of a first feeding stop period, and feeding the welding wire forward at a first feeding speed from an elapse of the first feeding stop period to an elapse of a predetermined period. The welding wire is fed backward after the elapse of the predetermined period.

A pulse welding period includes a first peak period for supplying a first peak current to a welding wire, a first base period for supplying a base current smaller than the first peak current to the welding wire, a second peak period for supplying a second peak current to the welding wire after alternately repeating the first peak period and the first base period (n1) times (n is an integer equal to or larger than 2), and a second base period for supplying the base current to the welding wire. The second peak current is larger than the first peak current, and droplets are transferred from the welding wire during the second peak period or the second base period.

An apparatus to provide welding power. The apparatus may include a direct current-alternate current (DC-AC) power converter to output a primary current and a transformer stage. The transformer stage may include at least one power transformer to receive the primary current from the (DC-AC) power converter on a primary side of the transformer stage and to output a first voltage through a first rectifier and a first set of secondary windings disposed on a secondary side of the transformer stage. The transformer stage may further include an auxiliary set of secondary windings disposed on the secondary side to output a second voltage. The apparatus may also include a pair of active unidirectional switches disposed on the secondary side to receive the second voltage from the auxiliary set of secondary windings.