This steel sheet has a base steel sheet, a coated portion, and an exposed portion, the shape of the end edge side of the steel sheet and the end portion on the outer side of the base steel sheet is a protruded curve represented by a curvature radius R1 and R1 is 5 μm or more.

A metal case has a bottom part composed of a metal plate, and a side wall part composed of a metal plate that stands from an outer peripheral edge of the bottom part. A boundary part between the bottom part and the side wall part includes a welding portion formed by welding the both parts together. The welding portion is exposed on a surface of the metal case on a lower side in a standing direction of the side wall part. And, a lower end that is a lower end part of the bottom part in the standing direction of the side wall part is located on the lower side in the standing direction than the welding portion is.

A terminal-equipped electric wire manufacturing method includes: an electric wire installation step of inserting a core-wire exposed part between inner wall surfaces of piece parts of a core-wire connection body, the core-wire exposed part having a core-wire diameter smaller than an interval between the inner wall surfaces of the piece parts; a melting step of melting the core-wire exposed part and the core-wire connection body by emitting a laser beam to the core-wire exposed part and the core-wire connection body from a free end side of each piece part; and a fixation step of fixing the core-wire exposed part and the core-wire connection body thus melted, with the emission of the laser beam stopped.

Method of manufacturing a dome comprising: providing a plurality of components; joining a first and a second component together, joining the first and second components together comprising: positioning the first component and the second component in an initial position in which the first surfaces of components are angled from each other by a first angle; melting a volume of material extending between the first and the second component, the volume of material increasing in thickness from the second surfaces to the first surfaces; and the volume of material cooling and solidifying so as to join the first component and the second component together, the cooling of the volume of material reducing the angle between the first surfaces to a second angle less than the first angle such that the first surfaces face towards a centre of the dome and the first and second components form part of the dome.

A weld with a stepped configuration is provided. The stepped configuration may be machined from a substrate to form a weld preparation which may accommodate a stepped weld. The weld with a stepped configuration and a controlled procedure exhibits improved service life and improved damage tolerance. A welded joint with a stepped configuration, a joined component with a stepped configuration, and method of welding a stepped configuration are also provided.

A laser welding method of the present disclosure includes a first step and a second step. In the first step, a first end of a first workpiece is positioned such that the first end of the first workpiece is overlapped on a second end of a second workpiece to form a corner joint. In the second step, the first end forming the corner joint is irradiated from above with a laser beam. Additionally, the first end is positioned to protrude relative to the second workpiece in the first step.

The present invention includes: a preparation process configured to provide a first metal member including an end portion with a vertical face, and a second metal member including an end portion with an inclined face, a higher melting point and a smaller plate thickness than the first metal member; a butting process configured to butt the end portions of the first metal member and the second metal member against each other and form a butted portion with a V-shaped gap; and a joining process configured to join the first metal member and the second metal member together by inserting the rotating rotary tool from only a front face of the first metal member and relatively moving the rotary tool along the butted portion while only the stirring pin is in contact with at least the first metal member.

An exterior panel is formed of superplastic materials, including an exterior skin of titanium to accommodate high thermal stresses imposed on hypersonic transport vehicles during hypersonic flight. The exterior skin is fixed to an underlying reinforcing skeletal structure consisting of a superplastic formable reinforcement (SFR) layer, for example a titanium, zirconium, and molybdenum (TZM) alloy, which supports the exterior skin whenever the latter may be heated to temperatures exceeding 1200 degrees Fahrenheit. The exterior panel includes a separate interior skin configured for attachment to a frame member such as a rib, stringer, or spar of the hypersonic transport vehicle. A multicellular core is sandwiched between the exterior and interior skins to impart tensile and compressive strength to the exterior panel. In one disclosed method, the core is superplastic formed and diffusion bonded to the exterior and interior skins.

A lap-fillet arc welding joint includes a weld bead, the weld bead being formed on an end portion of one sheet of overlapped two sheets and a surface of other sheet along the end portion. The other sheet includes a projecting portion projecting from the surface at a side of a weld toe of at least one of a start portion and a termination portion of the weld bead. The weld toe is located on a slope surface portion of the projecting portion at a side of the end portion of the one sheet.

A technique for producing tailored metal blanks composed of two pieces having different thickness involves modifying at least one piece to include a transition region. A thickness of a modified piece changes over the transition region so that a substantially similar thickness is provided along a joint of the two pieces. The two pieces, subsequent to modification, are joined via a welding process, which may be a laser welding process or a friction stir welding process.