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).

A modular two-part welding and processing platform is described. A cart section is capable of rotating around objects such as pipes and cylinders, or of linear travel along plates or the like. This cart section reversibly couples to a processing section supplied for instance with welding apparatus, painting apparatus, cleaning means, analysis means or the like. By means of this two-part device, work pieces can be cleaned, welded, and inspected quickly and accurately. Special marks may be provided on the work piece which in conjunction with sensors and motoring means on the cart, allow for precise positioning of the process head with respect to the work.

A modular two-part welding and processing platform is described. A cart section is capable of rotating around objects such as pipes and cylinders, or of linear travel along plates or the like. This cart section reversibly couples to a processing section supplied for instance with welding apparatus, painting apparatus, cleaning means, analysis means or the like. By means of this two-part device, work pieces can be cleaned, welded, and inspected quickly and accurately. Special marks may be provided on the work piece which in conjunction with sensors and motoring means on the cart, allow for precise positioning of the process head with respect to the work.

Systems and methods are disclosed for automatically activating or deactivating a gouging torch. In particular, the disclosed systems and methods activate and/or deactivate a gouging torch based on a valve operation selection. For example, for welding power supplies and/or welding wire feeders configured to operate both wire welding processes as well as gouging, a valve can be integrated with a gouging torch, which can be adjusted to allow or arrest the flow of compressed air to the gouging torch. In response, the welding power source and/or welding wire feeder automatically changes one or more output characteristics, to switch between a wire welding process and a gouging process without requiring the operator to interact with either the welding power source or welding wire feeder.

A welding or cutting system having a power supply with no user interface hardware or software for controlling the operation of the power supply, and a mobile communication device which contains an application allowing for control of the power supply. The mobile device is coupled to the power supply through either a wired or wireless connection.

A welding or cutting system having a power supply with no user interface hardware or software for controlling the operation of the power supply, and a mobile communication device which contains an application allowing for control of the power supply. The mobile device is coupled to the power supply through either a wired or wireless connection.

A multi-electrode submerged arc welding method enables, in multi-electrode submerged arc welding using five or six electrodes, a deep penetration and a large amount of deposit metal to be obtained by supplying a large current, and enables stable arc to be generated by respective electrodes by suppressing magnetic interference. Welding defects can be prevented, beads with a good shape or appearance can be obtained, and the welding speed can be increased.

A multi-electrode submerged arc welding method enables, in multi-electrode submerged arc welding using five or six electrodes, a deep penetration and a large amount of deposit metal to be obtained by supplying a large current, and enables stable arc to be generated by respective electrodes by suppressing magnetic interference. Welding defects can be prevented, beads with a good shape or appearance can be obtained, and the welding speed can be increased.

Provided is a method for bonding dissimilar metals to each other, the method comprising: dissimilar metal layer-forming steps (P2), (P3), (P4) for supplying, to form dissimilar metal layers; a second metal layer-forming step (P5) for supplying, on the surface of the dissimilar metal layers, a filler material formed of a second metal, and heating the filler material formed of the second metal to a temperature equal to or higher than a melting point of the second metal, to form a second metal layer formed of the second metal; and a second material-to-be-bonded welding step (P6) for welding a second material to be bonded that is formed of the second metal, onto the second metal layer.

In a fillet welded joint a base material tensile strength is 980 MPa or more, a carbon equivalent is 0.36 or more and 0.60 or less, a tensile strength [MPa] is 1950 times or more of the carbon equivalent [wt %], a weld metal average carbon equivalent is 0.45 or more and 0.65 or less, and at a prescribed position below a surface of a weld toe, a Vickers hardness HVbond at a boundary between the weld metal and a heat affected zone, an average value HVwmt of the Vickers hardness of the weld metal in a position 0.1-mm or more and 0.3-mm or less to the weld metal side of the boundary, and an average value HVhaz of the Vickers hardness of the heat affected zone in a position 0.1-mm or more and 0.3-mm or less to the heat affected zone side of the boundary satisfy HVbond≤HVwmt, HVbond≥HVhaz-50, and HVhaz≤350.