An additively manufactured object formed by depositing weld bead layers, each of the weld bead layers being obtained by melting and solidifying a filler metal made of a mild steel, the additively manufactured object includes a plurality of the weld bead layers having a ferrite phase with an average grain diameter of 11 μm or less in a part except for a surface oxide film.

A method of resistance spot welding a workpiece stack-up that includes a steel workpiece and an aluminum workpiece includes adhering an aluminum patch to faying surface of a steel workpiece, positioning an aluminum workpiece over the aluminum patch and the steel workpiece to assemble a workpiece stack-up, passing an electric current through the workpiece stack-up to create a molten aluminum weld pool, and terminating passage of the electric current to solidify the molten aluminum weld pool into a weld joint that bonds the steel and aluminum workpieces together through the aluminum patch. A workpiece stack-up having a weld joint that bonds an aluminum workpiece and a steel workpiece together through an aluminum patch is also disclosed. The weld joint establishes a bonding interface with the faying surface of the steel workpiece, and the aluminum patch is adhered to the faying surface of the steel workpiece around the weld joint.

A method for laser keyhole welding is disclosed to weld two pieces together made of a metal alloy. The method independently adjusts power in a focused center beam and power in a concentric focused annular beam. At the termination of a weld, the power of the annular beam is reduced, motion of the focused beams is stopped, the power of the center beam is increased, and the power of both beams is initially ramped down rapidly and then ramped down slowly. Increasing the power of the center beam equalizes the temperature of both pieces prior to solidification and cooling at the termination of the weld. An additional pulse of power may be applied to prevent the formation of defects or to erase any defects.

A fixture assembly for supporting a plurality of blanks during a shearing and welding operation. The fixture assembly includes a base frame. A rotating frame is rotatably connected to the base frame. A fixed block is fixed to the rotating frame for supporting a first blank. A moveable block is moveably connected to the rotating frame for supporting a second blank. A first clamp is provided for coupling the first blank to the fixed block. A second clamp is provided for coupling the second blank to the moveable block. A vertical actuator is coupled with the rotating frame and configured to move the moveable block in a vertical direction being perpendicular to a plane of the rotating frame for moving the second blank. A horizontal actuator is coupled with the rotating frame and configured to move the moveable block in a horizontal direction.

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.

A method of laser welding a steel substrate and a ductile iron substrate is disclosed along with a laser welded assembly that may be formed by practicing the disclosed method. The disclosed laser welding method involves forming a laser weld joint between the steel and ductile iron substrates. The laser weld joint includes a fusion zone comprised of austenite ferrous alloy that has a composition derived from intermixing molten portions of the steel and ductile iron substrates as part of the laser welding process. The austenite ferrous alloy that constitutes the fusion zone of the laser weld joint has a carbon content of 2 wt % or more and a nickel equivalent of 60% or more and can be achieved without preheating the steel and ductile iron substrates prior to welding or using a filler wire to introduce a foreign metal into the molten substrate material created by the laser beam.

A method is provided for manufacturing a mold for injection molding, especially for injection molding of optical components of automotive lighting devices. The method includes at least the following steps: providing a mold body, laser milling a pattern into a surface of the mold body, and coating the surface of the mold body by electroless nickel plating.

A welded joint comprising: a pair of steel base materials having a sheet thickness of 0.4 to 4.0 mm, and at least one of which has a tensile strength of 780 MPa or more; and a weld metal that welds the pair of steel base materials, wherein, when the weld metal is seen in plan view, a weld toe of the weld metal has peaks and valleys, an average distance in a direction orthogonal to a weld line direction between a top point of a peak and a bottom point of a valley that are adjacent to one another is 3.0 mm or less, and an average number of a total of peaks and valleys, at which the distance in the direction orthogonal to the weld line direction between the top point of the peak and the bottom point of the valley that are adjacent to one another is 0.1 mm to 3.0 mm, is 2 to 30/15 mm, and an automobile component having the welded joint.

A power transmission device and a method of manufacturing the same capable of shortening a shaft length and improving mountability are provided. A power transmission device according to the present disclosure includes a planetary carrier configured to support a pinion shaft pivotally supporting a pinion gear, rotatably support the pinion gear, and cause the pinion gear to revolve by rotation of the planetary carrier and a planetary carrier plate fixed fo face the planetary carrier on a side where the pinion gear is positioned, and including dog teeth integrally formed with the planetary carrier plate.

An electrically conductive tip member includes: an inner periphery portion including a Cu matrix phase and a second phase that is dispersed in the Cu matrix phase and contains a Cu—Zr-based compound, the inner periphery portion having an alloy composition of Cu-xZr (where x is the atomic percentage of Zr and satisfies 0.5≤x≤16.7); and an outer periphery portion that is present on an outer circumferential side of the inner periphery portion, made of a metal containing Cu, and has higher electrical conductivity than the inner periphery portion.