A welding method and a welding apparatus using the same control heat emission amounts of interfaces of a welding subject to be similar by adjusting cross-sectional areas of two welding tips arranged on both outer facing surfaces of a panel type welding subject, superimposed in multi-layers, to simultaneously form a nugget diameter.

A method of manufacturing a joining apparatus includes: providing a first metal member including an opening and a joint structure; providing a second metal member including an outer circumferential wall capable of contacting an inner circumferential wall that surrounds the opening and a joined structure, to which the joint structure is joined; causing the first metal member and the second metal member to move relative to each other, bringing one of a first joining section, which is configured by the inner circumferential wall and the outer circumferential wall, and a second joining section, which is configured by the joint structure and the joined structure, into contact, and separating the other joining section; starting energization between the first and the second metal members; bringing components of the other joining section into contact with each other; and joining the first and second joining sections by the relative movement and the energization.

A welding electrode may comprise a welding electrode body and a welding electrode cap that is connected or connectable to the welding electrode body for making contact between the welding electrode and a component for producing a welded connection. The problem of achieving an efficient heating of the sandwich sheet to be welded in a compact layout with the fewest possible modifications of the welding electrodes used heretofore is solved in that an electrically conductive resistance element integrated, or which can be integrated, in the welding electrode and which is connected or connectable in an electrically-conductive manner to the welding electrode body and the welding electrode cap is provided for the heating of the component. Furthermore, a method and a device with the welding electrode and a use are disclosed.

An alignment apparatus and an alignment method that enables to align an optical device with a receptacle, where the optical device and the receptacle have respective axes tilted to each other. The method includes steps of: (1) obtaining a minimum pressure caused to the optical device from the receptacle as varying a rolling angle around the X-axis of the optical device but fixing the pitching angle around the Y-axis at a rotating angle around the Z-axis; (2) determining a rotating angle where thus obtained minimum pressure becomes the minimum; and (3) iterating those procedures until the rotating angle obtained as varying the rolling angle and another rotating angle obtained as varying the pitching angle substantially coincides to each other.

A method of resistance welding a component to a sandwich sheet, which includes a thermoplastic layer disposed between two metallic outer layers, may involve heating a region of the sandwich sheet to be welded such that the thermoplastic layer softens, displacing the thermoplastic layer from the region by pressing the outer layers together, and welding the outer layers to the component by an electrical current flow for welding in a first circuit. The first circuit may include a first power source via a first welding electrode arranged at a side of the sandwich sheet and a second welding electrode arranged at a side of the component. This method is easy to run and achieves short cycle times due at least in part to the region being heated by a current flow for preheating in a second circuit that comprises a second power source and an electrical conductor that is arranged between the first welding electrode and the sandwich sheet.”

The present invention relates to steel used for a sash component and the like of a vehicle and, more specifically, to a hot-rolled steel sheet for a high-strength electric resistance welded steel pipe having excellent expandability and a method for manufacturing same, the hot-rolled steel sheet having a smaller decrease in the strength of a welding heat-affected zone (HAZ) formed during electric resistance welding, in comparison with a base material.

Structures for a tool surface of a downhole tool are constructed from a metal clay molded in a wet state. The wet state clay is a workable combination that can have a braze alloy grain, a tungsten carbide grain, and a binder. Additional cutting inserts can be embedded in the molded clay. Heat treatment applied to the molded metal clay causing the binder to be combusted and consumed. The braze alloy melts and then cools into a fused state with the tungsten carbide grain therein. The structure can affix to the tool surface of the tool by first being fused and then attached by brazing to the tool. Alternatively, the structure can be positioned in a fusible state adjacent the tool surface. When the heat treatment is applied, the structure fuses together and forms a metallurgical bond with the tool surface of the tool.

Provided are a hot-rolled steel sheet for an electric resistance welded steel pipe and a method for manufacturing the same, an electric resistance welded steel pipe and a method for manufacturing the same, a line pipe, and a building structure. The hot-rolled steel sheet has a chemical composition containing, by mass %, C: 0.030% or more and 0.20% or less, Si: 0.02% or more and 1.0% or less, Mn: 0.40% or more and 3.0% or less, P: 0.050% or less, S: 0.020% or less, N: 0.0070% or more and 0.10% or less, and Al: 0.005% or more and 0.080% or less, the balance being Fe and incidental impurities, in which N dissolved in steel is contained in an amount of 0.0010% or more and 0.090% or less, and letting a sheet thickness be t, a steel microstructure at a ½t position has an average grain size of 20.0 μm or less.

A preferable aspect of the present invention provides a hot-rolled steel sheet with excellent low-temperature toughness, a steel pipe using the same, and a manufacturing method therefor, wherein the hot-rolled steel sheet contains, by weight, 0.35-0.65% C, 0.01-0.4% Si, 13-26% Mn, 0.01-0.3% Ti, 0.01% or less B, 4% or less Al, 1-6% Cr, 0.05% or less P, 0.02% or less S, 0.01% or less N, 0.01-2% Cu, 0.001-0.015% Nb, and the balance Fe and other unavoidable impurities, the alloy elements satisfying the following relational formulas—[Relational formula 1] 70<[10*(C/12)+(Mn/55)+(Al/27)]*100<95 and [Relational formula 2] 4<100*(Cr/52+100*(Nb/93))<9; wherein a microstructure comprises, by area fraction, 97% or more (including 100%) of austenite and 3% or less (including 0%) of a carbide, the crystal grain size of the austenite being 18-30 μm or less; and wherein the size of the carbide is 0.5 μm or less.

Steel sheet low in cost and improved in fatigue characteristics without causing a drop in the cold formability, characterized in that it comprises an inner layer and a hard layer on one or both surfaces of the inner layer, a thickness of the hard layer is 20 μm or more and 40% or less of the thickness of the steel sheet, an average micro-Vickers hardness of the hard layer is 240 HV or more and less than 400 HV, an amount of C of the hard layer is 0.4 mass % or less, an amount of N is 0.02 mass % or less, a variation of hardness measured by a nanoindenter at a depth of 10 from the surface of the hard layer is a standard deviation of 2.0 or less, an average micro-Vickers hardness of the inner layer is 80 HV or more and less than 400 HV, a volume rate of carbides contained in the inner layer is less than 2.00%, and the average micro-Vickers hardness of the hard layer is 1.05 times or more the average micro-Vickers hardness of the inner layer.