According to an aspect of the present invention, there is provided a flux-cored wire including a steel sheath and a flux that fills the steel sheath. The flux contains fluorides of which a total value α of F-equivalent values is 0.21% or more, oxides of which the total value β of amounts ranges from 0.30% to less than 3.50%, and carbonates of which a total value of amounts ranges from 0% to 3.50%. An amount of CaO ranges from 0% to less than 0.20%. An amount of iron powder ranges from 0% to less than 10.0%. A X-value is 5.0% or less. The amount of CaF.sub.2 is less than 0.50%. The amount of Ti oxides ranges from 0.10% to less than 2.50%. A ratio of α to β ranges from 0.10 to 4.00. A total value of amounts of MgCO.sub.3, Na.sub.2CO.sub.3, and LiCO.sub.3 ranges from 0% to 3.00%. Other chemical composition is within a predetermined range. Ceq ranges from 0.45% to 1.20%.

According to an aspect of the present invention, there is provided a flux-cored wire including a steel sheath and a flux that fills the steel sheath. The flux contains fluorides of which a total value α of F-equivalent values is 0.21% or more, oxides of which the total value β of amounts ranges from 0.30% to less than 3.50%, and carbonates of which a total value of amounts ranges from 0% to 3.50%. An amount of CaO ranges from 0% to less than 0.20%. An amount of iron powder ranges from 0% to less than 10.0%. A X-value is 5.0% or less. The amount of CaF.sub.2 is less than 0.50%. The amount of Ti oxides ranges from 0.10% to less than 2.50%. A ratio of α to β ranges from 0.10 to 4.00. A total value of amounts of MgCO.sub.3, Na.sub.2CO.sub.3, and LiCO.sub.3 ranges from 0% to 3.00%. Other chemical composition is within a predetermined range. Ceq ranges from 0.45% to 1.20%.

A joining apparatus for the joining of a joining element to a workpiece on a joining surface, the joining apparatus comprising: a joining head that defines a joining axis; a cleaning device for cleaning the joining surface; and a drive unit for moving the cleaning device in relation to the joining head between a waiting position and a cleaning position. The waiting position axially rearward and transversely spaced from a holding device forwardmost on the joining head; and the cleaning position axially forward and transversely closer to the holding device

A joining apparatus for the joining of a joining element to a workpiece on a joining surface, the joining apparatus comprising: a joining head that defines a joining axis; a cleaning device for cleaning the joining surface; and a drive unit for moving the cleaning device in relation to the joining head between a waiting position and a cleaning position. The waiting position axially rearward and transversely spaced from a holding device forwardmost on the joining head; and the cleaning position axially forward and transversely closer to the holding device

A method of joining a steel first member to a stainless steel second member includes buttering a first joint surface on the first member, the buttering including: preheating the first joint surface; welding a border layer of weld material to the first joint surface; and heat treating the border layer and the first joint surface after welding the border layer. A weld is formed between the first and second members after heat treating the border layer and the first joint surface. The border layer and a second joint surface on the second member are preheated; and a body of weld material is added between the border layer and the second joint surface.

Used gas lift valves having a used bellows assembly are remanufactured. Separable components are disassembled, and the used bellows assembly is removed from a dome housing by de-brazing the used bellows at a brazed joint from a mating surface of the dome housing. A replacement bellows is then affixed (e.g., arc welded) to the dome housing's mating surface, and a bellows adapter is affixed (e.g., arc welded) to the replacement bellows. The separable components of the used valve are then reassembled to produce a remanufactured gas lift valve. The remanufactured valve has a replacement bellows composed of a nickel-chromium alloy as opposed to a nickel-copper alloy, has the replacement bellows arc-welded to the dome housing as opposed to being brazed thereto, and has the adapter arc-welded to the bellows as opposed to being brazed thereto.

Used gas lift valves having a used bellows assembly are remanufactured. Separable components are disassembled, and the used bellows assembly is removed from a dome housing by de-brazing the used bellows at a brazed joint from a mating surface of the dome housing. A replacement bellows is then affixed (e.g., arc welded) to the dome housing's mating surface, and a bellows adapter is affixed (e.g., arc welded) to the replacement bellows. The separable components of the used valve are then reassembled to produce a remanufactured gas lift valve. The remanufactured valve has a replacement bellows composed of a nickel-chromium alloy as opposed to a nickel-copper alloy, has the replacement bellows arc-welded to the dome housing as opposed to being brazed thereto, and has the adapter arc-welded to the bellows as opposed to being brazed thereto.

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.

Second member (20) includes a material that is difficult to weld to first member (10). First member (10) is provided with first penetrating part (11) penetrating in a thickness direction. Third member (30) is arc-welded to an inner peripheral surface of first penetrating part (11) and opening surface (10a) of first member (10) via second penetrating part (21) of second member (20). Second member (20) is compressed by flange (31) and first member (10) by solidification contraction of third member (30), and second member (20) is therefore fixed between flange (31) of third member (30) and first member (10).