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.

Properties and performance of weld material between metals in a weldment is controlled by modifying one or more of the nitrogen content and the carbon content to produce carbide (e.g. MC-type), nitride and/or complex carbide/nitride (e.g. MX-type) type precipitates. Fusion welding includes (i) adjusting shield gas composition to increase nitrogen/carbon gas and nitride/carbide species, (ii) adjusting composition of nitrogen/carbon in materials that participate in molten welding processes, (iii) direct addition of nitrides/carbides (e.g. powder form), controlled addition of nitride/carbide forming elements (e.g. Ti, Al), or addition of elements that increase/impede solubility of nitrogen/carbon or nitride/carbide promoting elements (e.g. Mn), and (iv) other processes, such as use of fluxes and additive materials. Weld materials have improved resistance to different cracking mechanisms (e.g., hot cracking mechanisms and solid state cracking mechanisms) and improved tensile related mechanical properties.

A method is disclosed for connecting two components by TIG welding, the components consisting of an air-hardening steel alloy and, for example, of the material T23 or T24. A joint is produced between the components that are to be connected, said joint widening, in particular, from an inside toward an outside. First, a root layer is welded in the region of the inside. Subsequently, a fill layer adjoining the root layer is welded, so that the joint is at least 90% filled. Finally, a cover layer is welded onto the fill layer, whereby the welding parameters are prespecified in such a manner that a temperature in an optimizing temperature range is adjusted on the inside in the region of the root layer.

A method is disclosed for connecting two components by TIG welding, the components consisting of an air-hardening steel alloy and, for example, of the material T23 or T24. A joint is produced between the components that are to be connected, said joint widening, in particular, from an inside toward an outside. First, a root layer is welded in the region of the inside. Subsequently, a fill layer adjoining the root layer is welded, so that the joint is at least 90% filled. Finally, a cover layer is welded onto the fill layer, whereby the welding parameters are prespecified in such a manner that a temperature in an optimizing temperature range is adjusted on the inside in the region of the root layer.

A pipeline is a pipeline having plural weld zones in which ends of plural steel pipes are joined by welding, the plural steel pipes are produced from plural charges of molten steel having one or more steel compositions; yield point elongation is not present on a stress-strain curve obtained when stress is applied in a longitudinal direction of each of the steel pipes; a thickness of each of the steel pipes t (mm) and an average pipe outside-diameter D (mm) satisfy t/D×100≦6; and in the plurality of the weld zones, ΔYS which is a yield strength difference between one steel pipe and the other steel pipe that are welded to each other (MPa), and YR representing a yield ratio that is a ratio of the yield strength to tensile strength of a pipe having a low yield strength out of the one steel pipe and the other steel pipe, satisfy ΔYS≦−1.75×YR+230.

The disclosed technology generally relates to consumable electrode wires and more particularly to consumable electrode wires having a core-shell structure, where the core comprises aluminum. In one aspect, a welding wire comprises a sheath having a steel composition and a core surrounded by the sheath. The core comprises aluminum (Al) at a concentration between about 3 weight % and about 20 weight % on the basis of the total weight of the welding wire, where Al is in an elemental form or is alloyed with a different metal element. The disclosed technology also relates to welding methods and systems adapted for using the aluminum-comprising electrode wires.

The disclosed technology generally relates to consumable electrode wires and more particularly to consumable electrode wires having a core-shell structure, where the core comprises aluminum. In one aspect, a welding wire comprises a sheath having a steel composition and a core surrounded by the sheath. The core comprises aluminum (Al) at a concentration between about 3 weight % and about 20 weight % on the basis of the total weight of the welding wire, where Al is in an elemental form or is alloyed with a different metal element. The disclosed technology also relates to welding methods and systems adapted for using the aluminum-comprising electrode wires.

A mobile hardbanding system that uses PTA welding to perform hardbanding on drill string sections at the well site. The inventive system allows alternate use of PTA and MIG welding. Both a PTA torch and a MIG torch are provided. Changing from one type of welding to the other is simplified by including separate electrical, gas, and cooling conduits for each torch. The torch not in use is parked in the welding compartment near the weld box. The powder hopper for the PTA welding assembly may be mounted on a swivel arm so that it can be moved out of the way when the MIG torch is in use.

A mobile hardbanding system that uses PTA welding to perform hardbanding on drill string sections at the well site. The inventive system allows alternate use of PTA and MIG welding. Both a PTA torch and a MIG torch are provided. Changing from one type of welding to the other is simplified by including separate electrical, gas, and cooling conduits for each torch. The torch not in use is parked in the welding compartment near the weld box. The powder hopper for the PTA welding assembly may be mounted on a swivel arm so that it can be moved out of the way when the MIG torch is in use.