A welding regime may implements cyclic short circuits under a closed loop voltage control approach. Upon clearing or imminent clearing of the short circuit, a current recess is implemented. The current recess reduces the current that would otherwise be applied to the weld, resulting in multiple benefits. The recess may be implemented by suspending voltage command signals. Following the current recess, normal control is resumed with the then-current voltage command.

A welding regime may implements cyclic short circuits under a closed loop voltage control approach. Upon clearing or imminent clearing of the short circuit, a current recess is implemented. The current recess reduces the current that would otherwise be applied to the weld, resulting in multiple benefits. The recess may be implemented by suspending voltage command signals. Following the current recess, normal control is resumed with the then-current voltage command.

A gas shielded arc welding method includes welding a steel sheet with a tensile strength of 780 MPa or more using a shielding gas containing Ar in an amount of 92 vol. % to 99.5 vol. %. In the gas shielded arc welding method, a value calculated from the following expression (1) is 0.20 or more: {√v/(D/2).sup.2}×10−{(100−C.sub.Ar)×I/v}×0.1 . . . (1), where C.sub.Ar represents an Ar content (vol. %) in the shielding gas, D represents an inner diameter (mm) of a nozzle from which the shielding gas is supplied, v represents a welding speed (cm/min), and I represents a welding current (A).

Devices and methods to extract a desired product from organic matter using supercritical fluid extraction processes are described herein. The extraction vessel generally includes a reaction chamber, a water jacket affixed to the reaction chamber capable of separate pressurization, and a closure mechanism with a gasket, a plug, and a cap ring with ACME threading. The extraction vessel may be sealed by hand closure without a need for additional tools to create a seal able to withstand pressures up to 5,000 psi.

Methods and apparatus to control hot-start weld current for arc ignition are disclosed. An example welding-type power supply includes a power converter to output welding-type current, a temperature monitor to determine a temperature of an electrode using at least one of a temperature measurement or a thermal model, and a current controller to control a hot-start weld current output by the power converter based on the temperature of the electrode.

In certain embodiments, a welding contact tip includes a first axial end portion having a welding wire outlet of an internal bore of the welding contact tip. The welding contact tip also includes a threaded middle portion adjacent the first axial end portion. The threaded middle portion includes external threads configured to mate with internal threads of a gas diffuser of a welding torch. The first axial end portion includes a tapered outer surface adjacent the threaded middle portion. In other embodiments, a welding torch assembly includes a gas diffuser having an outer circumferential groove having an outer surface with first and second walls that extend radially outward from first and second opposite axial sides of the outer surface, a nozzle having an inner circumferential rib with a tapered inner surface, and a compressible member disposed within the outer circumferential groove of the gas diffuser and the inner circumferential rib of the nozzle.

In certain embodiments, a welding contact tip includes a first axial end portion having a welding wire outlet of an internal bore of the welding contact tip. The welding contact tip also includes a threaded middle portion adjacent the first axial end portion. The threaded middle portion includes external threads configured to mate with internal threads of a gas diffuser of a welding torch. The first axial end portion includes a tapered outer surface adjacent the threaded middle portion. In other embodiments, a welding torch assembly includes a gas diffuser having an outer circumferential groove having an outer surface with first and second walls that extend radially outward from first and second opposite axial sides of the outer surface, a nozzle having an inner circumferential rib with a tapered inner surface, and a compressible member disposed within the outer circumferential groove of the gas diffuser and the inner circumferential rib of the nozzle.

A tool welding system is disclosed that includes a table that heats a tool. A multi-axis robot includes a welding head that is moved relative to the table in response to a command. A controller is in communication with the robot and generates the command in response to welding parameters. The weld parameters are based upon a difference between an initial tool shape and a desired tool shape. The difference between the initial tool shape and the desired tool shape corresponds to a desired weld shape. The desired weld shape is adjusted based upon initial tool shape variations, which includes thermal growth of the tool. The tool is welded to provide the desired weld shape to achieve a desired tool shape.

A tool welding system is disclosed that includes a table that heats a tool. A multi-axis robot includes a welding head that is moved relative to the table in response to a command. A controller is in communication with the robot and generates the command in response to welding parameters. The weld parameters are based upon a difference between an initial tool shape and a desired tool shape. The difference between the initial tool shape and the desired tool shape corresponds to a desired weld shape. The desired weld shape is adjusted based upon initial tool shape variations, which includes thermal growth of the tool. The tool is welded to provide the desired weld shape to achieve a desired tool shape.

A flux cored wire, which is obtained by filling the inside of a steel outer skin with a flux, is configured to have a composition that contains, in mass % relative to the total mass of the wire, 0.01-0.12% of C, 0.05% or more but less than 0.30% of Si, 1.0-3.5% of Mn, 0.1% or more but less than 1.0% of Ni, 0.10-0.30% of Mo, 0.1-0.9% of Cr, 4.5-8.5% of TiO.sub.2, 0.10-0.40% of SiO.sub.2, 0.03-0.23% of Al.sub.2O.sub.3 and 80% or more of Fe.