There is provided an arc welding control method of performing a forward/reverse feeding control of alternating a feeding rate of a welding wire between a forward feeding period and a reverse feeding period, and generating short-circuiting periods and arc periods to perform welding. The welding wire is fed forwardly at a time of staring the welding. The forward/reverse feeding control is started from the reverse feeding period of the welding wire after starting conduction of a welding current.

A welding device for a non-circular plate according to an embodiment includes a chuck for gripping and rotatably supporting a plurality of laminated non-circular plates, a welding torch for welding outer peripheral edge portions of the plurality of laminated non-circular plates, a stationary shield box, and a movable shield box which is position-adjustable with respect to the welding torch so as to form a shield space surrounding the welding torch with the stationary shield box.

The invention is an apparatus and method for Orbital welding of pipes or pipe segments together to form a pipeline, i.e., Orbital welding. A scanner welding unit, a control unit and a welding unit are combined to travel along and above a seam, which is formed between two interfacing base/cylindrical surfaces of every two pipe or pipe segments, scan the pipes/pipe segments relative positioning, alignment and levelling, and their surface geometry and topography and overlay a welding material starting from the root layer at the bottom of the seam and up to its edge and sealing it with a capping layer. The welding unit lowers a welding tip into the seam that may rotate on its axis at different angels relative to the surface during welding. The scanner unit may alert on mismatches on the relative position of the pipes/pipe segments before or after welding and in some cases enable repositioning for a more hermetically sealed weld.

A consumable electrode arc welding method using a shielding gas containing argon comprises: setting a first welding condition in which a first welding current is supplied to a welding wire; and setting a second welding condition in which a second welding current is supplied to a welding wire. The first welding condition and the second welding condition are welding conditions in which a reference current of the welding current is 350 A or higher and a current variation range is from 50 A to 150 A, and the first welding condition and the second welding condition are switched at a cycle of a frequency ranging from 1 Hz to 5 Hz.

A semiconductor device of an embodiment includes a SiC layer including a first trench, a second trench having first and second regions, an n-type first SiC region, a p-type second SiC region, an n-type third SiC region, a p-type fourth SiC region between the first trench and the first SiC region, and a p-type fifth SiC region between the second trench and the first SiC region and having a first portion and a second portion, a gate electrode in the first trench, a first electrode in the second trench, and a second electrode. A distance between the first trench and the first region is greater than a distance between the first trench and the second region, the first portion is separated from the fourth SiC region, the second portion contacts the fourth SiC region, the first region contacts the first portion, and the second region contacts the second portion.

A composite cemented carbide roll comprising an inner layer made of an iron-based alloy, and an outer layer made of cemented carbide which is metallurgically bonded to an outer peripheral surface of the inner layer; the cemented carbide of the outer layer comprising 55-90 parts by mass of WC particles and 10-45 parts by mass of an Fe-based binder phase having a particular composition; a shaft member and a shaft end member being metallurgically bonded to at least one axial end of the inner layer; the inner layer being made of an iron-based alloy containing 2.0% or more in total by mass of at least one selected from the group consisting of Cr, Ni and Mo; and the shaft member and the shaft end member being made of an iron-based alloy containing 1.5% or less in total by mass of at least one selected from the group consisting of Cr, Ni and Mo.

A composite cemented carbide roll comprising an inner layer made of an iron-based alloy, and an outer layer made of cemented carbide which is metallurgically bonded to an outer peripheral surface of the inner layer; the cemented carbide of the outer layer comprising 55-90 parts by mass of WC particles and 10-45 parts by mass of an Fe-based binder phase having a particular composition; a shaft member and a shaft end member being metallurgically bonded to at least one axial end of the inner layer; the inner layer being made of an iron-based alloy containing 2.0% or more in total by mass of at least one selected from the group consisting of Cr, Ni and Mo; and the shaft member and the shaft end member being made of an iron-based alloy containing 1.5% or less in total by mass of at least one selected from the group consisting of Cr, Ni and Mo.

A method of forming a sealed canister and a method of storing radioactive materials is provided. The method of forming includes placing a top plate on a top opening of a side wall, a bottom of the side wall being sealed to a base plate. The top plate includes a top surface with a top edge having a bevel and with a channel set in from the top edge. Finally, a weld is formed between the beveled top edge and the top opening of the side wall to seal the top plate to the side wall.

A welding system configured to weld a workpiece by using a welding device and a positioner includes a control device configured to control the welding device and the positioner. The positioner includes a workpiece position setting mechanism having reference position information, and at least one holding mechanism configured to hold the workpiece. The control device includes a positioner position calculation means for calculating a position of the holding mechanism when holding the workpiece based on the reference position information provided from the workpiece position setting mechanism and workpiece information inputted into the control device in advance.

A hardfacing metal composition and method of restoring worn work string tubing by application of a hardfacing metal to the worn regions of the work string tubing.