Provided is an austenitic stainless steel weld joint that is excellent in polythionic acid SCC resistance and naphthenic acid corrosion resistance, and is also excellent in creep ductility. An austenitic stainless steel weld joint includes a base material and a weld metal. The weld metal has a chemical composition at its width-center position and at its thickness-center position consisting of, in mass %, C: 0.050% or less, Si: 0.01 to 1.00%, Mn: 0.01 to 3.00%, P: 0.030% or less, S: 0.015% or less, Cr: 15.0 to 25.0%, Ni: 20.0 to 70.0%, Mo: 1.30 to 10.00%, Nb: 0.05 to 3.00%, N: 0.150% or less, and B: 0.0050% or less, with the balance: Fe and impurities.

Disclosed is an apparatus for arc welding, comprising: a torch body comprising a power supply line and a gas supply line; two or more metal segments movable relative to one another being sized and shaped to surround a seam between two elongated objects to be welded together, the two or more metal segments being in electrical communication with the power supply line; and a gas jacket attached to each of the metal segments.

A multiple welding method and a welding device with at least two electrodes which ensure a welding quality that is as consistent as possible and stable welding processes. A test parameter is applied to one of the at least two welding current circuits before the start or after the end of the multiple welding method and at least one electrical. welding parameter is recorded in at least one other welding current circuit, with an electrically conductive connection between the at least two welding current circuits being detected if the recorded welding parameter is influenced by the test parameter and fulfills a predetermined test criterion. Alternatively, at least one electrical welding parameter is recorded in each welding current circuit during the multiple welding method, with an electrically conductive connection between the at least two welding current circuits being detected if the recorded welding parameters change simultaneously.

A multiple welding method and a welding device with at least two electrodes which ensure a welding quality that is as consistent as possible and stable welding processes. A test parameter is applied to one of the at least two welding current circuits before the start or after the end of the multiple welding method and at least one electrical. welding parameter is recorded in at least one other welding current circuit, with an electrically conductive connection between the at least two welding current circuits being detected if the recorded welding parameter is influenced by the test parameter and fulfills a predetermined test criterion. Alternatively, at least one electrical welding parameter is recorded in each welding current circuit during the multiple welding method, with an electrically conductive connection between the at least two welding current circuits being detected if the recorded welding parameters change simultaneously.

A ball for a ball valve, wherein the ball comprises a substrate of metal having surface modified portions to act as seating surfaces for a seat of the ball valve; and a seat ring for a ball valve, wherein the seat ring comprises a substrate of metal having a surface modified portion to act as a seating surface for a ball of the ball valve.

Described herein are examples of weld training systems that show (e.g., transparent and/or translucent) “ghost” images of a welding tool on a display screen of a welding headgear to indicate target positions and/or target orientations of an actual welding tool. In some examples, the weld training systems may additionally “reset” the target tool image to a position closer to the actual welding tool if the target tool image gets too far away. The ability to “reset” the target tool image to a position closer to the actual welding tool may help in minimizing a risk that an operator 106 will overcompensate to try to catch up with the target tool image, which can be detrimental to the weld. Additionally, resetting the target tool image to a position closer the welding tool may allow an operator to better perceive and/or understand differences in orientation and/or other technique parameters.

The present invention relates to methods and apparatus for detection of fire states in the presence of welding activities. In some examples, the welding detection system may algorithmically calculate a risk of a fire state developing. In some embodiments, the welding fire detection and prevention system may communicate warning states to users, supervisors, equipment and/or building monitoring systems.

A welding torch includes a torch body and at least one device for feeding a consumable welding wire towards the tool center point that has an attachment device for attachment to the torch or an element connected thereto. A base support, which is connected to the attachment device, includes at least two deflection elements for guiding the wire towards the center point. The at least two deflection elements are arranged on the base support so that a first wire path length from the last deflection element located closest to the center point to the center point is shorter than a second wire path length between the last deflection element and a further deflection element as viewed counter to a main wire feed direction, and so that the arcuate wire has a greater segment height along the second path length than the segment height along the first path length.

Provided is an austenitic stainless steel weld joint that is excellent in polythionic acid SCC resistance and naphthenic acid corrosion resistance, and is also excellent in creep ductility. An austenitic stainless steel weld joint includes a base material and a weld metal. The weld metal has a chemical composition at its width-center position and at its thickness-center position consisting of, in mass %, C: 0.050% or less, Si: 0.01 to 1.00%, Mn: 0.01 to 3.00%, P: 0.030% or less, S: 0.015% or less, Cr: 15.0 to 25.0%, Ni: 20.0 to 70.0%, Mo: 1.30 to 10.00%, Nb: 0.05 to 3.00%, N: 0.150% or less, and B: 0.0050% or less, with the balance: Fe and impurities.

Apparatuses and methods for repairing a defect in a nuclear reactor are provided. The apparatus includes a body for insertion in a tubular structure, the body includes: an end effector having a weld torch operable to deposit weld material by forming molten weld droplets and depositing the weld droplets the tubular structure. A drive unit includes a brace for selectively anchoring against said tubular structure; at least one linear actuator for moving the apparatus relative to the brace; and a rotational actuator coupled to rotate the weld torch. The method includes inserting a repair apparatus into tubular structure of the nuclear reactor; moving the repair apparatus to a defect location; depositing a protective weld layer over the defect by sequentially depositing weld droplets atop a weld pool on the tubular structure, wherein the protective weld layer bonds to the tubular structure surrounding the defect.