The resistance spot welding method includes performing actual welding to squeeze, by a pair of electrodes (14), a sheet combination with a sheet thickness ratio of more than 3 in which a thin sheet (11) is overlapped on at least one face of two or more overlapping thick sheets (12, 13), and passing a current while applying an electrode force to join the sheet combination, wherein in the actual welding, a pattern of the current and the electrode force is divided into two or more steps including a first step and a second step to perform welding, and an electrode force F1 in the first step and an electrode force F2 in the second step satisfy a relationship

F1>F2.

A steel strip for an electric-resistance-welded steel pipe or tube having a strength of X70 grade or more and excellent HIC resistance and SSC resistance is provided. A steel strip for an electric-resistance-welded steel pipe or tube has a chemical composition containing, in mass %: C: 0.02% to 0.06%; Si: 0.1% to 0.3%; Mn: 0.8% to 1.3%; P: 0.01% or less; S: 0.001% or less; V: 0.04% to 0.07%; Nb: 0.04% to 0.07%; Ti: 0.01% to 0.04%; Cu: 0.1% to 0.3%; Ni: 0.1% to 0.3%; Ca: 0.001% to 0.005%; Al: 0.01% to 0.07%; and N: 0.007% or less, with a balance being Fe and incidental impurities, contents of C, Nb, V, and Ti satisfying the following Expression (1)

[C]−12([Nb]/92.9+[V]/50.9+[Ti]/47.9)≦0.03%  (1),

wherein a ferrite area ratio is 90% or more.

A steel strip for an electric-resistance-welded steel pipe or tube having a strength of X70 grade or more and excellent HIC resistance and SSC resistance is provided. A steel strip for an electric-resistance-welded steel pipe or tube has a chemical composition containing, in mass %: C: 0.02% to 0.06%; Si: 0.1% to 0.3%; Mn: 0.8% to 1.3%; P: 0.01% or less; S: 0.001% or less; V: 0.04% to 0.07%; Nb: 0.04% to 0.07%; Ti: 0.01% to 0.04%; Cu: 0.1% to 0.3%; Ni: 0.1% to 0.3%; Ca: 0.001% to 0.005%; Al: 0.01% to 0.07%; and N: 0.007% or less, with a balance being Fe and incidental impurities, contents of C, Nb, V, and Ti satisfying the following Expression (1)

[C]−12([Nb]/92.9+[V]/50.9+[Ti]/47.9)≦0.03%  (1),

wherein a ferrite area ratio is 90% or more.

A melt cutter includes a case, an electricity-connecting portion, a heating device, a working portion, a control portion, and a heat-dissipating device. The case has a heat-dissipating zone. The electricity-connecting portion is disposed in the case for connecting with an electricity source. The working portion is disposed in the case and has a gap with changeable size for clamping an object. The control portion alternatively triggers the heating device to heat and to transmit heat to the working portion, and it also reduces the size of the gap for melting and cutting the object. The heat-dissipating device is disposed at the heat-dissipating zone and is electrically connected with the electricity-connecting portion. Thereby, the heat-dissipating device helps air communication between interior and exterior of the case.

Production methods for producing a fibre-reinforced metal component having a metal matrix which is penetrated by a plurality of reinforcing fibres are provided. One method includes depositing in layers reinforcing fibres in fibre layers, depositing in layers and liquefying a metal modelling material in matrix material layers, and consolidating in layers the metal modelling material in adjacently deposited matrix material layers to form the metal matrix of the fibre-reinforced metal component. Here, the metal component is formed integrally from alternately deposited matrix material layers and fibre layers. An alternative method includes introducing an open three-dimensional fibrewoven fabric consisting of reinforcing fibres into a casting mould, pouring a liquid metal modelling material into the casting mould and consolidating the metal modelling material to form the metal matrix of the fibre-reinforced metal component. Here, the metal component is formed integrally from the consolidated metal modelling material and the reinforcing fibres.

Production methods for producing a fibre-reinforced metal component having a metal matrix which is penetrated by a plurality of reinforcing fibres are provided. One method includes depositing in layers reinforcing fibres in fibre layers, depositing in layers and liquefying a metal modelling material in matrix material layers, and consolidating in layers the metal modelling material in adjacently deposited matrix material layers to form the metal matrix of the fibre-reinforced metal component. Here, the metal component is formed integrally from alternately deposited matrix material layers and fibre layers. An alternative method includes introducing an open three-dimensional fibrewoven fabric consisting of reinforcing fibres into a casting mould, pouring a liquid metal modelling material into the casting mould and consolidating the metal modelling material to form the metal matrix of the fibre-reinforced metal component. Here, the metal component is formed integrally from the consolidated metal modelling material and the reinforcing fibres.

A transition structure includes a metallic portion, a fiber portion including a plurality of tows embedded within the metallic portion and extending out from the metallic portion forming a fabric, and a binding material forming a matrix surrounding the fiber portion embedded within the metallic portion. The fiber portion may be attached to or form part of a composite vehicle component. The transition structure may join a metallic component and a composite component. The transition structure may be manufactured by creating first channels within a layer of a metallic substrate, inserting fiber tows into the first channels, placing a first metallic layer over the metallic substrate and the fiber tows, consolidating the metallic layer to the metallic substrate, and binding the fiber tows within a resin. Prior to binding, additional layers of channels and fiber tows may be consolidated onto the first metallic layer.

To bond bonding target members stacked on top of each other without generating dust or spatter into an electrically bonded article with improved mechanical strength against strong vibration etc. A first bonding target member or second bonding target member includes a relative displacement amount setting portion for setting the distance by which the bonding target portion of the first member and the bonding target portion of the second member are relatively displaced during bonding, and a current conduction suppressing layer is formed on the relative displacement amount setting portion. The second or first member includes a setting face that is placed opposed to the current conduction suppressing layer of the first or second member. In a state where the first and second members have been positioned, the distance between the current conduction suppressing layer and the setting face is equal to the width H of the bonded portion.

To bond bonding target members stacked on top of each other without generating dust or spatter into an electrically bonded article with improved mechanical strength against strong vibration etc. A first bonding target member or second bonding target member includes a relative displacement amount setting portion for setting the distance by which the bonding target portion of the first member and the bonding target portion of the second member are relatively displaced during bonding, and a current conduction suppressing layer is formed on the relative displacement amount setting portion. The second or first member includes a setting face that is placed opposed to the current conduction suppressing layer of the first or second member. In a state where the first and second members have been positioned, the distance between the current conduction suppressing layer and the setting face is equal to the width H of the bonded portion.

A spot welded member includes a spot weld formed by holding a sheet stack of multiple steel sheets between a pair of electrodes and spot-welding the sheet stack, in which at least one of the multiple steel sheets is a high-strength zinc-based coated steel sheet having a tensile strength of 780 MPa or more, the high-strength zinc-based coated steel sheet having a coating with an Al content of 0.5% or more by mass, and in which the heat shock region of the spot weld outwardly extending from an edge of a corona bond area includes a coated layer including an FeAl alloy layer having an average thickness of 0.3 μm or more and a zinc-based coated layer having an average thickness of 2.0 μm or more on the FeAl alloy layer at the interface between the base steel sheet of the high-strength zinc-based coated steel sheet and the coating.