Abstract: A welding system and method is disclosed for girth welding high strength materials, including liquefied natural gas storage tanks, using a short arc welding process and a self-shielding electrode. The welding system contains a welding apparatus which advances the self-shielding electrode towards a workpiece to be welded and controls the arc length and the operation of the apparatus so that the weld satisfies the requirements for welding at least American Petroleum Institute Grade X-80 line pipe, or can weld liquefied natural gas storage tanks. The system additionally contains a power source with a controller for creating a current pulse introducing energy into the electrode to melt the end of the self-shielding electrode and a low current quiescent metal transfer section following the end of the melting pulse during which the melted electrode short circuits against the workpiece.

Abstract: A welding system is disclosed for performing a short arc welding process between an advancing wire electrode and a workpiece. The system comprises a power source with a controller for creating a current pulse introducing energy into the electrode to melt the end of the electrode and a low current quiescent metal transfer section following the end of the melting pulse during which the melted electrode short circuits against the workpiece; a timer to measure the actual time between the end of the pulse and the short circuit; a device for setting a desired time from the pulse to the short circuit; a circuit to create a corrective signal based upon the difference between the actual time and the desired time; and, a circuit responsive to the corrective signal to control a given parameter of the current pulse. Also disclosed is a strategy for arc welding utilizing a cored electrode that produces welds with low levels of contaminants and which are strong, tough, and durable.

Abstract: A welding system and method is disclosed for girth welding high strength materials using a short arc welding process and a self-shielding electrode. The welding system contains a welding apparatus which advances the self-shielding electrode towards a workpiece to be welded and controls the arc length and the operation of the apparatus so that the weld satisfies the requirements for welding at least American Petroleum Institute Grade X-80 line pipe. The system additionally contains a power source with a controller for creating a current pulse introducing energy into the electrode to melt the end of the self-shielding electrode and a low current quiescent metal transfer section following the end of the melting pulse during which the melted electrode short circuits against the workpiece.

Abstract: An electric arc welder for creating a welding process in the form of a succession of AC waveforms between a particular type of cored electrode, with a sheath and core, and a workpiece by a power source comprising an high frequency switching device for creating the individual waveforms in the succession of waveforms, each waveform having a profile is formed by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz where the profile is determined by the input signal to a wave shaper controlling the short current pulses; a circuit to create a profile signal indicative of the particular type of electrode; and a select circuit to select the input signal based upon the profile signal whereby the wave shaper causes the power source to crate a specific waveform profile for the particular type of cored electrode.

Abstract: Various slag systems exhibiting improved flow characteristics and weld puddle properties are provided. Also provided are flux cored electrodes for producing the noted slag systems and related methods of arc welding.

Abstract: Disclosed are techniques and compositions for arc welding consumables such as electrodes that reduce the energy otherwise required for the welding. Particularly, the techniques and electrode compositions can reduce the extent of contamination of weld metal in an arc welding operation. The techniques and compositions promote exothermic reactions during the welding process which reduce the energy otherwise required of the arc. Lower energy arcs can be of shorter length, which thereby reduce the potential for weld contamination by agents from the atmosphere or shielding gas. The techniques and compositions can also be used to selectively tailor shape of the resulting weld, achieve particular weld deposition rates, achieve particular cooling rates and thus influence weld properties, and also enable formation of certain phases in the weld metal.

Abstract: An electrode composition is disclosed, particularly useful for arc welding and utilized in a flux-cored arc electrode, which produces a slag that is readily removable. The electrode composition employs aluminum and magnesium in a atomic ratio of 1.5:1 or more, respectively. Also disclosed are methods for facilitating the removal of slag by use of particular electrode or welding compositions.

Abstract: A method of arc welding with a cored electrode comprising creating a positive waveform with a first shape and having a first time; creating a negative waveform with a second shape and having a second time; making one of the first and second shapes greater in magnitude than the other of the shapes; and, adjusting the percentage relationship of the first and second times so the time of the shape with the greater magnitude is substantially less than the time of the other shape.

Abstract: An electric arc welder for creating a welding process in the form of a succession of AC waveforms between a particular type of cored electrode, with a sheath and core, and a workpiece by a power source comprising an high frequency switching device for creating the individual waveforms in said succession of waveforms, each waveform having a profile is formed by the magnitude of each of a large number of short current pulses generated at a frequency of at least 18 kHz where said profile is determined by the input signal to a wave shaper controlling said short current pulses; a circuit to create a profile signal indicative of said particular type of electrode; and a select circuit to select said input signal based upon said profile signal whereby said wave shaper causes said power source to crate a specific waveform profile for said particular type of cored electrode.