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.

A process for preparing a multi-thickness welded steel vehicle rail, the process comprises the steps of: (a) forming a first tube having a first outer diameter, an inner diameter and a first wall thickness; (b) forming a second tube having the first outer diameter, a second inner diameter and a second wall thickness different than the first wall thickness; (c) swaging a first end of the first tube to a second outer diameter less than the second inner diameter of the second tube; (d) inserting the swaged first end of the first tube into an end of the second tube to form a joint; (e) welding the first tube and the second tube together to form a weld at the joint to form a tube blank with a heat affected zone of lower metal strength in the area of the weld; (f) preheating the tube blank to create a common crystalline microstructure along a length of the tube blank; (g) introducing the tube blank into a blow molding tool having inner molding walls; (h) molding the tube blank at an elevated temperature by expanding the tube blank against the inner molding walls of the molding tool by injecting a pressurized medium into an interior cavity of the tube blank; and (i) quenching the tube blank by replacing the pressurized medium with a cooling medium through the molding tool and the tube blank to achieve a rapid cooling effect on the tube blank and to create a completed vehicle rail with essentially uniform material strength across the weld. A completed vehicle rail has an overlapped welded structure and uniform microcrystalline structure along the length of the rail.

A process for preparing a multi-thickness welded steel vehicle rail, the process comprises the steps of: (a) forming a first tube having a first outer diameter, an inner diameter and a first wall thickness; (b) forming a second tube having the first outer diameter, a second inner diameter and a second wall thickness different than the first wall thickness; (c) swaging a first end of the first tube to a second outer diameter less than the second inner diameter of the second tube; (d) inserting the swaged first end of the first tube into an end of the second tube to form a joint; (e) welding the first tube and the second tube together to form a weld at the joint to form a tube blank with a heat affected zone of lower metal strength in the area of the weld; (f) preheating the tube blank to create a common crystalline microstructure along a length of the tube blank; (g) introducing the tube blank into a blow molding tool having inner molding walls; (h) molding the tube blank at an elevated temperature by expanding the tube blank against the inner molding walls of the molding tool by injecting a pressurized medium into an interior cavity of the tube blank; and (i) quenching the tube blank by replacing the pressurized medium with a cooling medium through the molding tool and the tube blank to achieve a rapid cooling effect on the tube blank and to create a completed vehicle rail with essentially uniform material strength across the weld. A completed vehicle rail has an overlapped welded structure and uniform microcrystalline structure along the length of the rail.

A method for producing a plate heat exchanger and the plate heat exchanger, particularly a soldered aluminium plate heat exchanger. In the method, a heat exchanger block is provided having a plurality of partition plates and edge strips arranged between the partition plates. A connection device is provided to be mounted on the heat exchanger block. A planar region for securing the connection device to the heat exchanger block is provided with at least one welded weld bead by means of a first weld. The connection device is welded onto the weld bead by means of a second weld. The welding method used for the first weld is a friction stir welding method.

A method for manufacturing a shaft body by welding a plurality of shaft members together and forming the shaft body, the method including: a primary tempering step of subjecting a range in at least one of the shaft members, which is in the vicinity of an end of another shaft member side adjacent thereto, to tempering before the shaft members are welded together so that a strength of an end side of a region thereof is lower than a strength at a side which is opposite to the end of the region thereof; a welding step of welding the shaft members together after the primary tempering step; and a secondary tempering step of tempering the vicinity of a weld part between the shaft members after the welding step.

A method for manufacturing a shaft body by welding a plurality of shaft members together and forming the shaft body, the method including: a primary tempering step of subjecting a range in at least one of the shaft members, which is in the vicinity of an end of another shaft member side adjacent thereto, to tempering before the shaft members are welded together so that a strength of an end side of a region thereof is lower than a strength at a side which is opposite to the end of the region thereof; a welding step of welding the shaft members together after the primary tempering step; and a secondary tempering step of tempering the vicinity of a weld part between the shaft members after the welding step.

A method of joining an aluminum workpiece and an adjacent overlapping steel workpiece by reaction metallurgical joining, and the resultant metallurgical joint formed between the two workpieces, are disclosed. The method involves compressing a reaction material located between the aluminum and steel workpieces and heating the reaction material momentarily to form a metallurgical joint that comprises bonding interface between the reaction material and the steel workpiece and a bonding interface between the reaction material and the aluminum workpiece. The reaction material is formulated to be able to interact with both aluminum and steel in order to establish the bonding interfaces of the metallurgical joint. Moreover, the practice of oscillating wire arc welding may be employed to deposit the reaction material in the form of a reaction material deposit onto the steel workpiece prior to assembling the steel and aluminum workpieces in a workpiece stack-up.

A method of joining an aluminum workpiece and an adjacent overlapping steel workpiece by reaction metallurgical joining, and the resultant metallurgical joint formed between the two workpieces, are disclosed. The method involves compressing a reaction material located between the aluminum and steel workpieces and heating the reaction material momentarily to form a metallurgical joint that comprises bonding interface between the reaction material and the steel workpiece and a bonding interface between the reaction material and the aluminum workpiece. The reaction material is formulated to be able to interact with both aluminum and steel in order to establish the bonding interfaces of the metallurgical joint. Moreover, the practice of oscillating wire arc welding may be employed to deposit the reaction material in the form of a reaction material deposit onto the steel workpiece prior to assembling the steel and aluminum workpieces in a workpiece stack-up.

A welding system and a method of control. The welding system may include a weld gun that may have an induction coil and a guide sleeve. The induction coil may heat a welding electrode in the weld gun. The guide sleeve may inhibit the welding electrode from engaging the induction coil.

Provided is a novel method for improving fatigue strength, which is applicable to any small portion that is covered with another member. A method for improving fatigue strength according to the present invention includes: disposing an aid (3, 15) to be opposed to an processing object (2A, 2B, 6) on which a fatigue strength improving process is performed, the aid being configured to assist the improving process; and generating sparks between the aid (3, 15) and the processing object (2A, 2B, 6).